Clinical Nuclear Medicine

Head-to-Head Comparison of 18F-FDG and 68Ga-FAPI-04 PET/CT for Radiological Evaluation of Cervical Cancer

Purpose We aimed to compare the potential value of 68Ga-FAPI-04 and 18F-FDG PET/CT in primary cervical cancer and lymph node metastases. Methods Patients with cervical cancer underwent both 68Ga-FAPI-04 and 18F-FDG PET/CT. Histopathology and follow-up CT or MRI results (at least 3 months of follow-up) were used as reference criteria. Paired-sample t test was used to compare the SUVmax of 18F-FDG and 68Ga-FAPI-04 PET/CT for cervical cancer primary lesions and metastatic lymph nodes. Results A total of 35 patients with a mean age of 53 ± 11 years (range, 30–76 years) were included. The detection rate of both tracers for primary tumors was 100%. There was no significant correlation between 18F-FDG and 68Ga-FAPI-04 for SUVmax (14.5 ± 5.7 vs 15.1 ± 6.2; P = 0.645). In addition, the detection rates of 68Ga-FAPI-04 and 18F-FDG for lymph node metastasis were 100% and 98%, respectively. No significant difference was found in SUVmax between 18F-FDG and 68Ga-FAPI-04 groups (7.6 ± 4.0 vs 7.0 ± 3.5; P = 0.572). Twelve false-positive lymph nodes were detected in 8 patients with 18F-FDG PET/CT, none of which were developed on 68Ga-FAPI-04 PET/CT. Conclusion 68Ga-FAPI-04 PET/CT has a high tracer rate for the diagnosis of primary cervical cancer and lymph node metastases. Moreover, 68Ga-FAPI-04 PET/CT also showed good results in distinguishing metastatic lymph nodes from reactive lymph nodes of cervical cancer.

Atypical Foot Swelling in Metastatic Endometrial Carcinoma: Role of FDG PET/CT

Abstract An 83-year-old woman with a history of endometrial carcinoma (EMC), treated with surgery and chemotherapy in August 2020, presented with a 1-year history of left foot swelling, tenderness, and heat. Despite multiple consultations, no diagnosis was made, and she developed painful swelling with a limping gait. A biopsy was done on July 14, 2023, confirmed metastatic EMC. FDG PET/CT revealed widespread metastases, including in the lungs, pleura, mediastinal, hilar, inguinal, right external iliac nodes, left labia majora, left iliac bone, left tibia, and left foot. Excision of left inguinal and vulvar tumors also confirmed metastatic EMC.

FDG PET/CT in a Case of Primary Ewing Sarcoma of the Uterus

A 23-year-old woman presented with prolonged menstruation for 10 days. Pelvic ultrasound showed multiple masses in the uterus, suspicious for leiomyomas. Pelvic MRI showed an irregular multinodular uterine mass involving the cervix, and bilateral enlarged extrailiac lymph nodes, suggesting uterine malignancy with lymph node metastases. FDG PET/CT showed heterogeneous activity of the uterine mass and multiple FDG-avid lymph nodes in the bilateral pelvic and retroperitoneal regions, suggesting uterine malignancy with multiple lymph node metastases. Hysterectomy, bilateral salpingo-oophorectomy, and pelvic and retroperitoneal lymph node dissection revealed EWSR1-rearranged Ewing sarcoma of the uterus and no malignancy in the resected lymph nodes.

18F-FDG PET/CT Findings of an Isolated Splenic Metastasis From Endometrial Adenocarcinoma

Abstract Splenic metastasis from endometrial carcinoma is rare, especially when the spleen is the sole metastatic site. Herein, we report the case of a 47-year-old woman with a history of endometrial adenocarcinoma diagnosed 1 year ago. At that time, she underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic node dissection. Restaging 18 F-FDG PET/CT demonstrated an isolated splenic mass with elevated FDG activity. There were no other signs of recurrence. The lesion was surgically resected and diagnosed as a metastasis from the endometrial adenocarcinoma.

Adrenal and Bone Metastases as the Initial Presentation of Endometrial Carcinoma Diagnosed by 18F-FDG PET/CT

Abstract Adrenal and bone metastases as the initial presentation of endometrial carcinoma are rare. We report a case of endometrial carcinoma in a 47-year-old woman with initial manifestation as right chest wall pain, which was suspected as adrenal cortical carcinoma with rib metastasis after diagnostic CT scan. However, uterine and pelvic bone lesions were revealed by staging FDG PET/CT. Eventually, endometrial carcinoma with adrenal and bone metastases was confirmed pathologically.

18F-FDG PET and 18F-FDG PET/CT in Vulvar Cancer

Aim The aims of this study were to determine the role of 18F-FDG PET/CT in vulvar cancer patients and to extract summary estimates of its diagnostic performance for preoperative lymph node staging. Patients and Methods PubMed/Medline and Embase databases were searched to identify studies evaluating 18F-FDG PET/CT in vulvar cancer patients. The assessment of methodological quality of the included articles was performed. Per-patient and per-groin pooled estimates, with 95% confidence intervals (CIs), of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratio (DOR) were calculated. Results Ten articles were included in the systematic review, 7 among which evaluated the diagnostic performance of preoperative 18F-FDG PET/CT for lymph node staging. Qualitative per-patient analysis (72 patients from 4 studies) resulted in estimated pooled sensitivity, specificity, PPV, NPV, and DOR of 0.70 (95% CI, 0.44–0.95), 0.90 (95% CI, 0.76–1.04), 0.86 (95% CI, 0.66–1.06), 0.77 (95% CI, 0.56–0.97), and 10.49 (95% CI, 1.68–65.50), respectively. Qualitative per-groin analysis (245 groins from 5 studies) resulted in estimated pooled sensitivity, specificity, PPV, NPV, and DOR of 0.76 (95% CI, 0.57–0.94), 0.88 (95% CI, 0.82–0.94), 0.70 (95% CI, 0.55–0.85), 0.92 (95% CI, 0.86–0.97), and 19.43 (95% CI, 6.40–58.95), respectively. Conclusions Despite limited literature data, this systematic review and meta-analysis revealed that a negative preoperative PET/CT scan may exclude groin metastases in at least early-stage vulvar cancer patients currently unfit for sentinel node biopsy and select those eligible for a less invasive surgical treatment. A positive PET/CT result should otherwise be interpreted with caution. Larger prospective studies are needed to confirm these results and to evaluate the diagnostic value of standardized semiquantitative analysis compared with the qualitative one.

Walthard Cell Nests Leading to 18F-FDG Increased Uptake of Fallopian Tube

Abstract We present 18F-FDG PET/CT findings of fallopian tube with Walthard cell nests. The images revealed a thickening of the bilateral fallopian tubes with increased FDG uptake. Malignant tumor or tuberculosis of the fallopian tube was suspected. Histopathology suggested fallopian tube with Walthard cell nests.

A Scallop-shaped Photopenic Region in the Urinary Bladder Area on Tc-99m MDP Bone Scan Caused by a Uterine Cervical Leiomyoma

A 46-year-old woman with right breast invasive ductal carcinoma and sternalgia underwent Tc-99m methylene diphosphonate (MDP) whole-body bone scintigraphy, on which a scallop-shaped photopenic region in the urinary bladder area was found, besides increased radioactivity in the sternum region and both breasts. By reviewing a previous CT scan, a pelvic mass oppressing the right wall of the urinary bladder was noted, which was confirmed to be a rare uterine cervical leiomyoma by biopsy.

68Ga-FAPI-04 PET/MR Versus 18F-FDG PET/CT in the Detection of Ovarian Cancer

Abstract A 75-year-old woman presented with right lower abdominal pain. Pelvic ultrasound showed a cystic solid mass in the right adnexa. Painless enlarged lymph nodes on the left supraclavicular side with biopsy were suggestive of metastatic cancer. 18F-FDG PET/CT performed to evaluate the primary tumor showed intense uptake in both regions of the right adnexa and the gastric sinus, but 68Ga-FAPI PET/MRI showed uptake only in the right adnexal region. A subsequent gastroscopic biopsy confirmed atrophic inflammation. Finally, surgery histopathology revealed ovarian cancer. This case demonstrated that 68Ga-FAPI PET/MRI may help exclude suspected primary gastric carcinoma with false-positive 18F-FDG uptake.

18F-FDG PET/CT Findings in a Patient With Uterine Inflammatory Myofibroblastic Tumor

A large intrauterine mass was detected in a 49-year-old woman who presented with irregular vaginal bleeding and intermittent fever. 18 F-FDG PET/CT revealed a massive intrauterine tumor with heterogeneous and elevated 18 F-FDG uptake. Histopathological analysis of the hysterectomy specimen confirmed the diagnosis of an inflammatory myofibroblastic tumor of the uterus.

18F-FAPI-04 PET/CT in the Evaluation of Patients With Cervical Cancers

Background: To explore the potential utility of 18F-AlF-NOTA-fibroblast activation protein inhibitor (FAPI)-04 PET/CT (denoted as 18F-FAPI-04 PET/CT) in the evaluation of cervical cancer through a head-to-head comparison with 18F-FDG PET/CT for detecting primary tumors and metastatic lymph nodes. Patients and Methods: A total of 22 patients with a pathologic diagnosis of cervical cancer underwent 18F-FDG PET/CT and 18F-FAPI-04 PET/CT within a 7-day period. Out of the 22 patients, 19 (median age, 62.3 y) were included in the final analysis. Comparisons were made between the ability of 18F-FDG PET/CT and 18F-FAPI-04 PET/CT to detect primary lesions and metastatic lymph nodes; semiquantitative PET/CT parameters were also analyzed, including SUVmax, SUVmean, metabolic tumor volume (MTV for 18F-FDG) and fibroblast tumor volume (FTV for 18F-FAPI-04), tumor lesion glycolysis (TLG for 18F-FDG) and tumor lesion FAPI (TLF for 18F-FAPI-04), and tumor-to-background ratios (TBRliver and TBRblood), calculated by dividing the SUVmax of the lesion by the SUVmean of normal liver or blood pool. Results: 18F-FAPI-04 PET/CT identified a greater number of primary lesions and metastatic lymph nodes compared with 18F-FDG PET/CT. 18F-FAPI-04 PET/CT detected 19/19 primary tumors, achieving a detection rate of 100%, while 18F-FDG PET/CT identified 18/19 primary tumors, with a detection rate of 95%. The PPV for both tracers was 100%, the NPV for 18F-FDG PET/CT was 0%. For metastatic lymph nodes, 18F-FAPI-04 PET/CT detected 82 nodes in 7 patients, while 18F-FDG PET/CT detected 44 nodes in the same 7 patients. TBR was significantly higher for 18F-FAPI-04 PET/CT compared with 18F-FDGPET/CT for primary lesions (TBRblood: 16.33 vs 9.83, P = 0.005; TBRliver: 21.59 vs 7.04, P < 0.0001) and metastatic lymph nodes (TBRblood: 9.16 vs 7.64, P = 0.033; TBRliver: 10.38 vs 5.29, P < 0.0001). No significant differences were observed in other semiquantitative parameters. Conclusions: 18F-FAPI-04 PET/CT had superior performance in detecting primary lesions and metastatic lymph nodes in cervical cancer compared with 18F-FDG PET/CT. 18F-FAPI-04 exhibited lower uptake in normal tissues, leading to a higher TBR. These findings imply that 18F-FAPI-04 PET/CT has potential for clinical application in cervical cancer.

Cervical Paraganglioma Negative on Both 68Ga-DOTATATE and 18F-FDG PET/CT Studies

A 66-year-old woman with a nodule between the bladder and the vagina underwent both 68 Ga-DOTATATE and 18 F-FDG PET/CT. Neither study showed increased activity in the nodule. Cervical paraganglioma was diagnosed from the pathologic examination.

18F-FDG PET/CT Findings in a Patient With Primary Sarcomatoid Carcinoma of the Uterus

Primary sarcomatoid carcinoma of the uterus is a rare and highly malignant neoplasm with a poor prognosis. Herein, we reported a case of uterine sarcomatoid carcinoma in a 55-year-old woman with colporrhagia for 1 month. 18F-FDG PET/CT showed intense 18F-FDG uptake of the uterine tumor with hypermetabolic pelvic lymph node and pulmonary nodules. Histopathology and immunohistochemistry of the uterine lesion tissue confirmed the diagnosis of sarcomatoid carcinoma after needle biopsy.

18F-AlF-NOTA-FAPI-04 Superior to 18F-FDG PET/CT in Detecting Primary Tumor and Metastatic Lymph Nodes in a Cervical Cancer Patient

Abstract A 41-year-old woman with an enlarged right supraclavicular lymph node underwent a fine-needle biopsy, which confirmed the presence of metastatic squamous cell carcinoma. To identify the primary tumor, an 18F-FDG PET/CT scan was performed, revealing multiple metabolically active lymph nodes throughout the body, but no primary lesion was identified. Subsequently, an 18F-AlF-NOTA-FAPI-04 PET/CT scan was conducted, which demonstrated increased abnormal uptake in the cervix and revealed additional metabolically active lymph nodes. Thus, a biopsy of the uterine cervical region was performed, and the results confirmed cervical squamous cell carcinoma.

Skull Base Metastasis of Uterine Carcinosarcoma Mimicking Primary Carcinoma of the Middle Ear

Abstract Uterine carcinosarcoma is a rare type of endometrial carcinoma with poor prognosis. A bone metastasis to the skull base is extremely scarce in uterine carcinosarcoma. A 54-year-old woman with uterine carcinosarcoma complained of right ear otorrhea and otalgia. 18F-FDG PET/CT presented an increased FDG uptake at the right middle ear involving the mastoid process and external acoustic meatus. Primary carcinoma of the middle ear was considered according to clinical symptoms and PET manifestation. However, the skull base metastasis from uterine carcinosarcoma was pathologically confirmed. The rare metastasis from uterine carcinosarcoma should be differentiated from primary carcinoma of the middle ear.

The Application of 18F-FES PET in Clinical Cancer Care

Introduction [18F]fluoroestradiol (FES) can be used for the noninvasive visualization and quantification of tumor estrogen receptor (ER) expression and activity and was FDA-approved as a diagnostic agent in May 2022 for detecting ER-positive lesions in patients with recurrent or metastatic breast cancer. PET imaging was also used to detect ER-positive lesions and malignancy among patients with uterine, ovarian, and other ER-positive solid tumors. We conducted a systemic review of the studies on FES PET imaging used among patients with cancer not limited to breast cancer to better understand the application of FES PET imaging. Methods PubMed/MEDLINE and Cochrane Library databases were used to perform a comprehensive and systematic search and were updated until August 15, 2022. Two authors independently reviewed the titles and abstracts of the retrieved articles by using the search algorithm and selected the articles based on the inclusion and exclusion criteria. All statistical analyses were conducted using R statistical software. Results Forty-three studies with 2352 patients were included in the qualitative synthesis, and 23 studies with 1388 patients were included in the quantitative analysis, which estimated the FES-positive detection rate. Thirty-two studies (77%) included breast cancer patients in 43 included studies. The FES SUVmean was higher in patients with endometrial cancer (3.4–5.3) than in those with breast cancer (2.05) and uterine sarcoma (1.1–2.6). The pooled detection rates of FES PET imaging were 0.80 for breast and 0.84 for ovarian cancer patients, both similar to that of 18F-FDG. The FES uptake threshold of 1.1 to 1.82 could detect 11.1% to 45% ER heterogeneity, but the threshold of FES uptake did not have consistent predictive ability for prognosis among patients with breast cancer, unlike uterine cancer. However, FES uptake can effectively predict and monitor treatment response, especially endocrine therapy such as estradiol, ER-blocking agents (fulvestrant and tamifoxen), and aromatase inhibitors (such as letrozole and Z-endoxifen). Conclusions [18F]fluoroestradiol PET is not only a convenient and accurate diagnostic imaging tool for detecting ER-expressing lesions in patients with breast and ovarian cancer but also among patients with uterine cancer. [18F]fluoroestradiol PET is a noninvasive predictive and monitoring tool for treatment response and prognosis.

68Ga-FAPI PET/CT Visualized Benign Metastasizing Leiomyoma With Bone Invasion

Abstract Benign metastasizing leiomyoma (BML) is a rare disease associated with pelvic leiomyoma. We report 18F-FDG and 68Ga-FAPI PET/CT findings in a 51-year-old woman with multiple BMLs. The mass in the abdominopelvic cavity and other metastatic lesions showed highly increased 68Ga-FAPI uptake, whereas uptake of 18F-FDG in those lesions was low. Our report demonstrates that 68Ga-FAPI PET/CT showed a different result in detecting BML to 18F-FDG PET/CT, and 68Ga-FAPI PET/CT may be a promising method for whole-body evaluate metastases.

Massive Hepatocellular Carcinoma Combined With Giant Uterine Fibroid on 18F-FDG PET/CT

Abstract A 50-year-old woman was admitted due to a liver mass discovered by ultrasound in routine physical examination. MRI demonstrated a large hepatocellular carcinoma. It also discovered an abdominal mass simultaneously. 18F-FDG PET/CT was performed for staging. PET/CT showed mixed and mild metabolism of the hepatic lesion and giant abdominopelvic mass, respectively. Hepatocellular carcinoma combined with a benign mass in abdominopelvic cavity from uterine was considered and finally proved pathologically. We present a rare case of woman with large liver cancer accompanied by giant uterine fibroid where 18F-FDG PET/CT helped in making the right diagnosis.

Ovarian Metastasis From Diffuse Epithelioid Malignant Mesothelioma Revealed by 18F-FDG PET/CT

Abstract Diffuse epithelioid malignant mesothelioma (MM) with metastasis to the ovary is rare. We reported FDG PET/CT findings in a 39-year-old woman with ovarian metastasis from diffuse epithelioid MM. The ultrasound findings at the external hospital revealed multiple masses in the hepatic hilus. FDG PET/CT examination was recommended to evaluate the nature of the lesions. It showed that 2 hypodense lesions in the perihepatic space had intense activity, and there was an additional FDG lesion in the right ovary, which was later confirmed as diffuse epithelioid MM with ovarian metastasis by pathological examination.

Peritoneal and Nodal Gliomatosis Mimicking Metastasis on FDG PET/CT in a Patient With Ovarian Immature Teratoma

Abstract Peritoneal and nodal gliomatosis is a rare disease condition characterized by implants of mature glial tissue on the peritoneum and lymph nodes. It is typically associated with teratoma and has no adverse effect on prognosis. We present a case of 22-year-old woman who underwent FDG PET/CT for the staging of ovarian immature teratoma. PET/CT revealed mildly increased FDG uptake in the peritoneal cavity and increased FDG uptake in the internal mammary and cardiophrenic angle lymph nodes, which were histopathologically diagnosed as peritoneal and nodal gliomatosis. This case suggests that PET/CT findings of peritoneal and nodal gliomatosis could mimic metastasis.

Hypermetabolic Broad Ligament Leiomyoma in Postmenopausal Women Mimicking Ovarian Tumors on 18F-FDG PET/CT

Abstract Extrauterine leiomyomas are rare and often occur in broad ligament or fallopian tube. Diagnosis of broad ligament leiomyoma is challenging for its solid nature and special location. Leiomyomas typically exhibit mild FDG uptake, especially in postmenopausal woman. We here reported a 57-year-old postmenopausal woman with intense FDG-avid broad ligament leiomyoma on 18F-FDG PET/CT, which might be misdiagnosed as ovarian tumor.

Simultaneous Time-of-Flight PET/MR Identifies the Hepatic 90Y-Resin Distribution After Radioembolization

Abstract A 61-year-old woman with multiple hepatic metastases from uterus cervical cancer received 90Y radioembolization. The simultaneous time-of-flight (TOF) PET/MR clearly identified the untreated tumor parts on the posttherapeutic 90Y internal pair-production imaging. After another boosted 90Y injection, the metastatic hepatic tumors were well covered. The follow-up PET/MR revealed tumor shrinkage. The one-stop-shop TOF PET/MR provided useful follow-up information in patients receiving 90Y radioembolization.

Prognostic Value of FDG PET/CT in Patients With Neuroendocrine Carcinoma of the Uterine Cervix

Purpose We evaluated the prognostic value of metabolic parameters measured on pretreatment FDG PET/CT in patients with cervical neuroendocrine carcinomas (NECs). Methods A total of 22 patients with cervical NECs who underwent pretreatment FDG PET/CT were retrospectively reviewed. The SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesion were measured. The associations between prognostic factors and progression-free survival (PFS) and overall survival (OS) were investigated using the Kaplan-Meier method, log-rank test, and univariate and multivariate Cox proportional hazards model. Results Of the 22 patients, 12 developed disease progression, and 5 died during the follow-up period. Univariate analyses revealed that MTV, TLG, and the International Federation of Gynecology and Obstetrics stage were significantly associated with PFS (all P < 0.05), whereas SUVmax did not show a significant correlation with PFS. Kaplan-Meier survival curves revealed that patients with MTV >31.9 cm3 (log-rank, P < 0.001), TLG >154.3 (log-rank, P < 0.001), and higher International Federation of Gynecology and Obstetrics stage (log-rank, P = 0.026) had significantly shorter PFS. In the multivariate analyses, MTV (P = 0.017; hazard ratio [HR], 7.298; 95% confidence interval [CI], 1.427–37.316) and TLG (P = 0.003; HR, 15.175; 95% CI, 2.470–93.244) were independent prognostic factors, whereas for OS, the univariate analysis revealed that only TLG >154.3 showed statistical significance (P = 0.043; HR, 9.821; 95% CI, 1.080–89.290). Conclusions Metabolic tumor volume and TLG on FDG PET/CT were the significant prognostic factors of PFS in patients with cervical NECs. Patients with high MTV and TLG had worse clinical outcomes. In addition, TLG may also be a predictor of OS.

Impact of 18F-FDG PET on the Management in Patients With Recurrent Gynecologic cancer

Purpose Gynecological cancer is the most prevalent cancer among women worldwide. We performed a meta-analysis to assess the impact of 18F-FDG PET on the management of patients with recurrent gynecological cancers, including cervical, uterine, and ovarian cancers. Methods We systematically searched MEDLINE and EMBASE databases for English-language publications. All published studies on the impact of PET scans on the management of patients with recurrent gynecological cancers were reviewed. The proportion of management change (%), defined as the percentage of patients whose management changed after FDG PET to those who underwent FDG PET, was calculated. The data from each study were analyzed using MedCalc Statistical Software version 14.12.0 (MedCalc Software, Ostend, Belgium). Results Nineteen studies including 6191 patients were eligible for inclusion. The impact of FDG PET scan for detecting recurrence/metastasis in patients with gynecologic cancer was evaluated using management change rates, ranging from 9.4% to 60.7% with a pooled effect of 42.0% (95% confidence interval [CI], 34.5%–49.6%; I 2 = 92.9%). In the subtype analysis, FDG PET scanning resulted in changes in the management in 48.5% (95% CI, 37.8%–59.3%; I 2 = 67.8%) of cervical cancer, 34.7% (95% CI, 33.4%–36.0%; I 2 = 0%) of uterine cancer, and 40.3% (95% CI, 26.7%–54.7%; I 2 = 95.2%) of ovarian cancer cases. Conclusions FDG PET has a significant impact on the restaging of patients with gynecological cancer. These findings suggest that FDG PET should be performed, especially in cases of suspected recurrence/metastasis in the main gynecologic cancer types, including cervical, ovarian, and uterine cancers.

18F-Fluciclovine PET/MRI in a Patient With Squamous Cell Carcinoma of the Uterine Cervix Correlated With 18F-FDG PET/CT

Abstract A 32-year-old woman with a FIGO (International Federation of Gynecology and Obstetrics) stage IIA invasive squamous cell carcinoma of the uterine cervix underwent a clinical FDG PET/CT scan, which revealed intense uptake in the primary. On research 18F-fluciclovine PET/MRI, the primary showed elevated fluciclovine uptake at 5 and 40 minutes after radiotracer injection, with no evidence of regional or distant metastasis. Fluciclovine PET may have diagnostic value for cervical cancer imaging with a potential advantage over FDG of minimal urinary activity from renal excretion; however, in this patient, the metabolic activity was inferior to that of FDG PET.

Hypermetabolic Subserosal Uterine Leiomyoma With Synchronous Atypical Multiple Myeloma Mimicking Ovarian Malignancy With Multiple Bone Metastases on 18F-FDG PET/CT

Abstract Subserosal cystic myoma with intense FDG uptake can resemble malignant cystic ovarian tumor and may lead to a false-positive diagnosis. A 49-year-old woman presented with chest pain for 4 months, and the initial chest CT showed multiple bone lesions. 18F-FDG PET/CT revealed not only multiple osteolytic lesions with FDG uptake but also a highly FDG-avid mass abutting the right side of the uterus. Ovarian malignancy with multiple bone metastases was considered initially. Subsequent biopsy confirmed multiple myeloma, and a subserosal uterine myoma was diagnosed by transvaginal sonography.

Development and Validation of 18F-FDG PET/CT-Based Models for Predicting Successful Complete Cytoreduction During Primary Cytoreductive Surgery for Advanced Ovarian cancer

Purpose The aim of this study was to develop an 18F-FDG PET/CT-based model to predict complete cytoreduction during primary cytoreductive surgery (CRS) for ovarian cancer (OC). Patients and Methods We retrospectively identified patients with stage III–IV OC who underwent primary CRS between June 2013 and February 2020 at 2 tertiary centers. Patients from each hospital were assigned to training and test sets. The abdominal cavity was divided into 3 sections, and data for the PET/CT-derived parameters were collected through image analysis. Various prediction models were constructed by combining clinicopathologic characteristics and PET/CT-derived parameters. The performance of the model with the highest area under the receiver operating characteristic curve (AUC) was externally validated. Results The training and test sets included 159 and 166 patients, respectively. The median age of patients in the test set was 55 years; 72.3% of them had stage III tumors, and 65.4% underwent complete cytoreduction. Metabolic tumor volume, total lesion glycolysis, and the number of metastatic lesions above the upper margin of the renal vein (area A) were selected among the PET/CT parameters. The best predictive multivariable model consisted of CA-125 (<750 or ≥750 IU/mL), number of metastatic lesions (<2 or ≥2), and metabolic tumor volume of area A, predicting complete cytoreduction with an AUC of 0.768. The model was validated using a test set. Its predictive performance yielded an AUC of 0.771. Conclusions We successfully developed and validated a preoperative model to predict complete cytoreduction in advanced OC. This model can facilitate patient selection for primary CRS in clinical practice.

FDG PET/CT Findings in a Patient With Ovarian Metastasis of Pheochromocytoma

Abstract Pheochromocytoma metastasizing to the ovary is extremely rare. We report the case of a 59-year-old woman who underwent right adrenal pheochromocytoma resection 14 years ago and remained asymptomatic until recently when she complained of palpitation, perspiration, and hypertension. 18F-FDG PET/CT revealed a left adnexal mass with increased activity, which was later surgically removed and pathologically confirmed as ovarian metastasis of pheochromocytoma.

Incidental Finding of an Ovarian Carcinoid on 11C-Methionine PET/CT

Abstract A 68-year-old woman with a history of multiple myeloma on regular hematological follow-up and with no previous relevant gynecological diseases was found to have an incidental focal uptake by the right ovary at 11C-methionine PET/CT (C-MET). Transvaginal ultrasound was then performed showing a 2-cm solid right ovarian mass with irregular borders and moderate vascularization at color Doppler examination. Therefore, the patient underwent bilateral salpingectomy, and the final histological results revealed a rare presentation of mature teratoma with insular carcinoid tumor arising from the right ovary.

Hyperestrogenism on 18F-FDG PET/CT in a Patient With Estrogen-Producing Ovarian Clear Cell Carcinoma

Abstract A 78-year-old woman was referred to the gynecologic outpatient department because she was suspected of having ovarian cancer based on an imaging study performed during a general medical examination. Further examination using 18F-FDG PET/CT revealed a bulky mass lesion with low FDG avidity, as well as surprisingly strong bilateral breast radiotracer uptake despite the patient's age. Thus, an estrogen-producing tumor was suspected. Bilateral salpingo-oophorectomy was performed, and surgical pathology diagnosed the tumor as clear cell carcinoma of the ovary.

Ovarian Metastasis as Initial Presentation of Pancreatic Carcinoma on FDG PET/CT

Abstract Pancreatic carcinoma metastasizing to the ovary is rare. We report the case of a 69-year-old woman with ovarian metastasis as initial presentation. Ultrasonography revealed a multicystic mass in the right adnexa, which was considered a malignancy. FDG PET/CT performed to detect possible metastasis revealed a right adnexal mass with mild activity and an additional FDG focus in the tail of the pancreas, which later proved to be ovarian metastasis from pancreatic carcinoma.

Solitary Cerebellar Metastasis of Ovarian Cancer Detected by FDG PET/CT

Abstract Ovarian cancer with solitary metastasis to the cerebellum is very rare. We presented a 58-year-old woman complaining of headaches 9 months after debulking surgery and chemotherapy due to ovarian cancer. The serum CA125 level was elevated. FDG PET/CT was then recommended to identify potential malignancy and showed a hypermetabolic mass in the right cerebellum. The cerebellar mass was surgically removed, and the pathology confirmed metastasis from ovarian cancer.

Solitary Axillary Lymph Node Metastasis From Ovarian Cancer on 18F-FDG PET/CT

Abstract Solitary axillary lymph node metastasis from ovarian cancer is rare. A 74-year-old woman who had undergone hysterectomy and bilateral salpingo-oophorectomy for ovarian cancer 2 years ago presented to our hospital with enlarged axillary lymph node. 18F-FDG PET/CT revealed left axillary lymphadenopathy with an SUVmax of 8.92. The postbiopsy pathology confirmed metastasis of poorly differentiated ovarian adenocarcinoma. This case highlights the need to consider ovarian cancer metastasis in cases of solitary axillary lymphadenopathy with intense FDG uptake, especially in patients with a recent history of ovarian cancer.

The Search for New 2-18F-FDG PET/CT Imaging Biomarkers in Advanced Ovarian Cancer Patients

Performance of Multiparametric Functional Imaging to Assess Peritoneal Tumor Burden in Ovarian Cancer

Purpose The aim of the study was to evaluate the clinical utility of pretreatment 18F-FDG PET/CT with quantitative evaluation of peritoneal metabolic cartography in relation to staging laparoscopy for ovarian carcinomatosis. Patients and Methods A retrospective review of prospectively collected data from 84 patients with FIGO (International Federation of Gynecology and Obstetrics) stage IIIC to IV ovarian cancer was carried out. All patients had a double-blinded 18F-FDG PET/CT review. Discriminant capacity of metabolic parameters to identify peritoneal carcinomatosis in the 13 abdominal regions according to the peritoneal cancer index was estimated with area under the receiver operating characteristic curve (AUC). Results The metabolic parameter showing the best trade-off between sensitivity and specificity to predict peritoneal extension compared with peritoneal cancer index score was the metabolic tumor volume (MTV), with a Spearman ρ equal to 0.380 (P < 0.001). The AUC of MTV to diagnose peritoneal involvement in the upper abdomen (regions 1, 2, and 3) ranged from 0.740 to 0.765. MTV AUC values were lower in the small bowel regions (9–12), ranging from 0.591 to 0.681, and decreased to 0.487 in the pelvic region 6. 18F-FDG PET/CT also improved the detection of extra-abdominal disease, upstaging 35 patients (41.6%) from stage IIIC to IV compared with CT alone and leading to treatment modification in more than one third of patients. Conclusions 18F-FDG PET/CT metrics are highly accurate to reflect peritoneal tumor burden, with variable diagnostic value depending on the anatomic region. MTV is the most representative metabolic parameter to assess peritoneal tumor extension.

Lateral Hepatic Fissure Peritoneal Carcinomatosis as a Pitfall for Hepatic Metastasis of Advanced Ovarian Cancer

Abstract A 52-year-old woman previously treated for a stage IIIc high-grade ovarian serous carcinoma presented right upper quadrant abdominal pain, 3 years after extended surgery and chemotherapy. Abdominal CT, MRI, and 18F-FDG PET/CT showed a right hepatic mass, consistent for lone recurrence nearby the hepatic lateral fissure. Preoperative and histologic examination identified a peritoneal lateral fissure lesion. The patient underwent atypic segment 5 segmentectomy. She has been disease-free for 3 years now. Advanced ovarian cancer can be responsible for perihepatic sulcus lesions, such as this right fissure lesion. They should not be mistaken for inoperable parenchyma metastases.

Ovarian Inflammation Mass Mimicking Recurrent Rectal Cancer 17 Years After Surgery

Abstract A 58-year-old woman diagnosed with rectal cancer received surgery and chemotherapy 17 years ago, and since then, she has been tumor-free. However, 1 month ago, she complained of progressive abdominal and pelvic pain. MRI scans revealed a soft-tissue ovarian mass with heterogeneous signals in the right pelvis, showing obvious enhancement after contrast injection. On PET/CT images, the lesion presented with intense FDG accumulation. Above imaging findings raised the possibility of tumor recurrence, and thus exploratory laparotomy was performed. Pathological results confirmed the diagnosis of active inflammation with fibrous tissue hyperplasia.

Solitary Vulvar Involvement of Ovarian Non-Hodgkin Lymphoma Mimicking Bartholin’s Abscess on 18F-FDG PET/CT

Abstract A 49-year-old woman was diagnosed with diffuse large B-cell lymphoma of the left ovary. Two months after the hysterectomy and bilateral salpingo-oophorectomy operation, the patient was referred to 18F-FDG PET/CT for staging. A mass lesion measuring 2.8 × 3 cm with intense 18F-FDG uptake was observed at right labium majus, which could be considered as a Bartholin’s cyst or abscess. The lesion was excised, and non-Hodgkin lymphoma involvement of vulva was revealed by histopathology.

Application of Multimodal Imaging Biomarker in the Differential Diagnosis of Ovarian Mass

Purpose The aim is to investigate the diagnostic performance of multimodal imaging with 18F-FDG PET/CT, MRI, and contrast-enhanced CT (CECT) in cases with unilateral or bilateral ovarian mass without ancillary findings of malignancy. Methods Retrospectively, 307 patients who had unilateral or bilateral ovarian masses and underwent preoperative FDG PET/CT and/or MRI/CECT were included. The criterion standard for the ovarian mass was the final pathology. The peak standardized uptake value (SULpeak) among benign tumors (BTs), borderline ovarian tumors (BoTs), and malignant ovarian tumors (MTs) were compared. The cutoff value of SULpeak to discriminate between BT/BoT and MT was determined from the training (n = 200) and validation (n = 131) cohorts. Diagnostic performances of SULpeak, Ovarian-Adnexal Reporting Data System (O-RADS) MRI score, CECT findings, and combination of multimodal imagings were analyzed. Results SULpeak of MT was significantly higher than that of BT or BoT (P < 0.05). There was no significant difference in SULpeak between BT and BoT (P = 0.147). The cutoff value of SULpeak for discriminating between BT/BoT and MT was 1.76 (sensitivity, 87.0%; specificity, 83.0%). Diagnostic performance for BT/BoT versus MT of O-RADS MRI, CECT, FDG PET/CT plus O-RADS MRI score, and FDG PET/CT plus CECT yielded the respective sensitivities of 100%, 94%, 95%, and 82%, and specificities of 43%, 46%, 88%, and 91%, respectively. Conclusions Multimodal imaging biomarkers including FDG PET/CT and MR/CECT could provide additional information to differentiate ovarian masses.

18F-FDG PET/CT for Staging and Response Evaluation in a Rare Case of Childhood Ovarian Primitive Neuroectodermal Tumor

Abstract Primitive neuroectodermal tumor (PNET) is an aggressive small cell malignancy. Apart from the central nervous system, they can arise from peripheral sites as well. Ovarian PNETs are extremely rare neoplasms. We here present a case of childhood ovarian PNET, where 18F-FDG PET/CT was efficiently used for staging and response evaluation.

Metabolic Response by 18F-FDG PET/CT in Metastatic Malignant Struma Ovarii Treated With Targeted Therapies

Abstract Malignant struma ovarii (MSO) is a rare malignant ovarian tumor, histologically identical to differentiated thyroid cancers. Given the rarity of this disease, there are no treatment guidelines, and the place of imaging for response assessment remains controversial. We report a metabolic response assessed by 18F-FDG PET/CT in a 71-year-old woman with radioiodine-refractory metastatic MSO treated by targeted therapies (first line with lenvatinib and second line with pazopanib). This case of exceptional response also highlights the usefulness of 18F-FDG PET/CT for therapeutic assessment of targeted drugs in such a rare clinical entity of malignant MSO.

68Ga–Prostate-Specific Membrane Antigen PET/CT in Ovarian Tumors

Purpose of the Report Ovarian cancer is usually diagnosed in an advanced stage of disease due to the absence of specific symptoms and a lack of sensitive diagnostic methods. Prostate-specific membrane antigen (PSMA) is expressed on prostate cancer cells but can be found in other tumors such as ovarian cancer. The aim of this pilot study was to evaluate the feasibility of using 68Ga-PSMA-11 PET/CT in detection of ovarian neoplasm before surgical treatment. Patients and Methods Eight women with mean age of 56.0 ± 16.2 years were included in the study. All patients underwent transvaginal ultrasound followed by CT scan of the chest and abdomen as qualification for surgery. Within a 1-week interval, PET/CT was performed on a Siemens Biograph scanner, 60 minutes after injection of 2 MBq/kg 68Ga-PSMA-11. Results In 3 cases (37.5%), the 68Ga-PSMA-11 PET/CT was positive, whereas histological examination confirmed 2 serous ovarian cancer cases and 1 ovarian borderline tumor. The SUVmax in the serous ovarian cancer was 8.7 and 4.1, and in the borderline ovarian tumor, it was 13.8. No correlation was found between antigen CA-125 level and 68Ga-PSMA expression. Range of tumor SUVmax was not correlated with stage of disease. The remaining 62.5% (5/8) were negative in 68Ga-PSMA-11 PET/CT, and histopathology confirmed benign pelvic tumor. Conclusions The initial experience supports the potential to use 68Ga-PSMA-11 in ovarian cancer to differentiate malignant and benign tumors before surgery. This study was approved by the Ethical Committee of the Medical University of Warsaw (KB/2/A/2018).

Mediastinal Recurrence of Uterine Cervix Cancer on 18F-FDG PET/CT

Abstract We report the case of a 64-year-old woman with a mediastinal relapse of a uterine cervix cancer with positive human papillomavirus, an unusual site of recurrence. She consulted because of solid and liquid dysphagia of sudden appearance. Endoscopic study and non–contrast-enhanced CT showed intraluminal esophageal stenosis with a retrograde esophageal distension. 18F-FDG PET/CT demonstrated an infiltrating hypermetabolic lesion in posterior mediastinum, middle and lower esophagus, and stomach, with no signs of local or regional relapse of the uterine neoplasm.

Incidental Diagnosis of Right Renal Subcapsular Urinoma on an 18F-FDG PET/CT Scan Performed for Staging of Cervical Cancer

Abstract A 53-year-old woman with cervical cancer underwent FDG PET/CT staging, which demonstrated an avid cervical mass with right parametrial involvement and presence of bilateral lymph node metastases. The right ureter was encased, resulting in obstruction and renal pelvic dilatation. Avid right renal subcapsular lesions were also noted, which were hyperintense on T2-weighted imaging compatible to encapsulated fluid collections. These lesions were diagnosed as subcapsular urinoma due to transmitted back pressure caused by obstruction of the right ureter.

Synchronous Isolated Ovarian Metastasis From Endometrioid Endometrial Carcinoma on FDG PET/CT

Women with ovarian metastasis from endometrial cancer are more likely to have >50% myometrial invasion, high-grade non-endometrioid tumors, and lymphovascular space invasion. Low-grade endometrioid endometrial cancers with <50% myometrial invasion and negative lymphovascular space invasion have a very low rate (0.5%) of ovarian metastasis. We describe FDG PET/CT findings in a case of low-grade endometrioid endometrial cancer with <50% myometrial invasion, negative lymphovascular space invasion, negative lymph node metastasis, and synchronous isolated unilateral small ovarian metastasis. Both the primary and metastatic tumors showed intense FDG activity.

[68Ga]Ga-DOTATATE PET/CT in Well-differentiated Ovarian Neuroendocrine Tumor Associated With Mature Cystic Teratoma

A well-differentiated ovarian neuroendocrine tumour (NET) associated with a mature cystic teratoma is rarely reported in the literature: the histologic diagnosis of these tumours is challenging due to the absence of defined guidelines for such lesions. Molecular imaging using [ 68 Ga]Ga-DOTATATE PET/CT can play a pivotal role in evaluating somatostatin receptor (SSTR) expression for NET and assessing morphologic features for diagnosing teratoma, especially in patients of ovarian NET associated with mature cystic teratoma in single individual. In addition, [ 68 Ga]Ga-DOTATATE PET/CT offers advantages for implementing theranostic approaches in the treatment of these rare tumours, should this be contemplated.

[68Ga]Ga-FAPI-46 PET/MRT Unveils Lymph Node Metastases and Changes Treatment Strategy in Recurrent Advanced High-grade Serous Ovarian Carcinoma Patient

High-grade serous ovarian carcinoma (HGOC) is frequently diagnosed at an advanced stage, leading to high recurrence rates. This case report highlights the utility of [68Ga]Ga-FAPI-46 PET/MRI in detecting previously unidentified lymph node metastases in a 75-year-old woman with recurrent HGOC, which altered the treatment strategy. The imaging revealed increased [68Ga]Ga-FAPI-46 uptake in nonenlarged mediastinal and left perihilar lymph nodes, reclassifying the patient from FIGO IIIb to FIGO stage IV and prompting a change in therapeutic management.

Unexpected Radioiodine Uptake in 131I Whole-Body Scan

Abstract A 23-year-old woman underwent a near-total thyroidectomy approximately 4 months prior due to papillary carcinoma. To eliminate residual thyroid tissue, she was administered 130 mCi of 131I during her initial radioiodine therapy session. After receiving therapy for 3 days, a focus of radioiodine uptake was noted in the left pelvic cavity on the posttherapy 131I whole-body image. Further analysis using SPECT/CT imaging pinpointed the uptake to the left ovary. Histopathological findings confirmed the presence of a mature teratoma in the ovary.

Pulmonary Metastases From Early-stage Granulosa Cell Tumor 15 Years Later on 18F-NOTA-FAPI-04 and 18F-FDG PET/CT

This article reports a case of rare pulmonary metastases arising from an ovarian granulosa cell tumor using 18F-NOTA-FAPI-04 PET/CT. We discussed a patient who was diagnosed with ovarian granulosa cell tumor (stage IA) after surgery 15 years ago and developed pulmonary metastases. The metastatic lesions with solid and (or) cystic components displayed variable (none to mild) fluorodeoxyglucose (FDG) avidity and significantly higher uptake of FAPI. This case highlighted the utility of 18F-NOTA-FAPI-04 PET/CT, suggesting that it may serve as a promising novel tool for the diagnosis and staging of ovarian granulosa cell tumors.

Metastatic Lung Adenocarcinoma Presenting Within Struma Ovarii

Abstract Tumor-to-tumor metastasis is extremely rare. We herein describe a 67-year-old woman who underwent FDG PET/CT for initial staging of lung cancer. This imaging examination revealed a pelvic mass with peripheral FDG uptake, suggesting a metastatic tumor from lung cancer or a secondary malignancy. Examination of a surgical specimen confirmed metastatic lung adenocarcinoma within a struma ovarii, suggesting tumor-to-tumor metastasis.

Intense FAP Expression of Ovarian Metastatic Breast Cancer Detected by [68Ga]RTX-1363 PET/CT

Abstract PET/CT targeting fibroblast activation protein α (FAP) in cancer-associated fibroblasts shows promise in theranostics. Here, we report the case of a 31-year-old woman with hormone receptor–positive/human epidermal growth factor receptor 2–negative breast cancer who presented with rising CA15-3 for further diagnostic workup. Whereas [18F]FDG PET/CT was unremarkable, novel [68Ga]RTX-1363 PET/CT revealed intense tracer accumulation in thoracoabdominal lymph nodes and both ovaries. Follow-up imaging confirmed tumor progression, and diagnostic laparoscopy verified metastatic disease in the ovaries with high FAP expression in the tumor stroma. This case underscores the superior sensitivity of [68Ga]RTX-1363 PET/CT over [18F]FDG PET/CT, enhancing breast cancer diagnostic and therapeutic strategies.

“Cancer Integrin” αvβ6 Imaging With 68Ga-Trivehexin PET/CT in Assessment of Ovarian Carcinoma

Abstract Peritoneal cancer index is an integral parameter for preoperative assessment of peritoneal disease. Current imaging modalities including 18F-FDG PET/CT, though superior to CT, underestimate the disease extent, mainly due to its high physiological background activity. Novel “cancer integrin” targeting imaging with 68Ga-trivehexin demonstrates limited physiological activity in the abdomen with superior target-to-background ratio than 18F-FDG PET/CT. Thus, we describe the first case demonstrating potential utility of novel “cancer integrin” αvβ6 imaging agent 68Ga-trivehexin for assessment of disease burden in advanced epithelial ovarian cancer.

Vaginal Mucosal Melanoma on 18F-FDG and 68Ga-FAPI-04 PET/CT

Vaginal mucosal melanoma is rare and insidious. A 74-year-old woman underwent 18 F-FDG and 68 Ga-FAPI-04 PET/CT for vaginal masses. The masses showed significant uptake of 68 Ga-FAPI compared with 18 F-FDG. In our case, this indicates the potential value of 68 Ga-FAPI-04 PET/CT in the diagnosis of mucosal melanoma.

131I-MIBG and 18F-FDG PET/CT in a Case of Synchronous Right Pheochromocytoma and Undifferentiated Uterine Carcinoma

Pheochromocytomas are rare catecholamine-secreting tumors arising from the adrenal medulla, often presenting with episodic hypertension, palpitations, and diaphoresis. Meanwhile, undifferentiated carcinoma of the uterine corpus is an aggressive and poorly differentiated endometrial malignancy with a high propensity for metastasis and poor prognosis. The incidental detection of such an aggressive malignancy in a patient undergoing evaluation for pheochromocytoma is exceedingly rare and poses significant diagnostic and therapeutic challenges. Here, we present a case of a 63-year-old woman who was being evaluated for right pheochromocytoma and underwent 131 I-MIBG scan for the same, which led to incidental detection of synchronous uterine carcinoma.

Intense FDG Uptake in Leiomyomatosis Peritonealis Disseminata With Fumarate Hydratase Deficiency

Abstract A 35-year-old woman with a history of laparoscopic myomectomy presented with repeated abdominal pain. Contrast-enhanced abdominal and pelvic CT showed multiple enhancing solid or mixed cystic and solid peritoneal masses, and an enhancing uterine mass. All these masses showed intense FDG uptake on FDG PET/CT. The intraperitoneal and uterine masses were surgically removed. The histological and immunohistochemical findings of the peritoneal lesions were consistent with leiomyomatosis peritonealis disseminata with fumarate hydratase deficiency, and the uterine mass was adenomyosis. This case indicates fumarate hydratase-deficient extrauterine leiomyoma can show intense FDG uptake mimicking malignancy.

Radiation Recall Myositis Detected With 18F-FDG PET/CT After a Treatment of Cervical Cancer

Abstract A 34-year-old woman, after being treated for cervical cancer, presented with severe pain in the inguinal and the upper abdominal region with restriction in range of motion of the trunk 71 days after radiation therapy and 19 days after receiving adjuvant gemcitabine and cisplatin chemotherapy. The 18F-FDG PET/CT showed complete response to cancer treatment, but also revealed a localized inflammatory process that was delimited by radiation fields rather than anatomical structures, suggesting a radiation recall phenomenon.

Predicting Malignancy in Adnexal Tumors With FAPI PET/CT and FDG PET/CT

Abstract A 54-year-old woman presented with a 55 × 64-mm tumor in the ovary with high [18F]FDG uptake on [18F]FDG PET/CT highly suggestive of ovarian cancer. Prior to surgery, the patient underwent [68Ga]-Ga- fibroblast activation protein inhibitor (FAPI)-46 PET/CT, which revealed low [68Ga]-Ga-FAPI-46 tumor uptake. Histopathology revealed a borderline ovarian tumor, which has low malignant potential and a 10-year survival rate greater than 93%. High [18F]FDG uptake is considered a fair predictor of malignancy in adnexal tumors. The present case demonstrates the potential superiority of [68Ga]-Ga-FAPI-46 PET/CT over [18F]-FDG PET/CT in differentiating malignant adnexal tumors from borderline ovarian tumors.

Ovarian Clear Cell Adenocarcinoma With Low 68Ga-FAPI-46 and Low 18F-FDG Uptake on PET/CT

Abstract A 67-year-old woman presented with a 12 × 20 × 24-cm adnexal tumor. Ultrasonography revealed an irregular, multilocular tumor, with increased flow in the solid components, and ascites—features that are consistent with ovarian cancer. The patient underwent 18F-FDG PET/CT and 68Ga-FAPI-46 PET/CT, both of which showed low uptake values. Histopathology confirmed ovarian clear cell adenocarcinoma (OCCC), a less common subtype that is underrepresented in FAPI PET/CT studies so far. Low 18F-FDG uptake is a known feature of OCCC and has been previously reported; however, this case identifies OCCC as a potential pitfall in 68Ga-FAPI-46 PET/CT.

Unveiling Ovarian Cancer With [18F]FDG and [68Ga]Ga-FAPI-46 PET/CT

A 71-year-old woman presented with fatigue, dyspnea, and weight gain, suggestive of a serious systemic disease. CT revealed a large pericardial effusion, and subsequent [18F]FDG PET/CT showed focal areas of elevated FDG uptake in the pericardium and moderate, symmetric FDG uptake in normal-sized ovaries. Pericardial effusion cytology indicated a gynecological malignancy. Additional [68Ga]Ga-FAPI-46 PET/CT demonstrated more distinct uptake in the pericardium and lymph nodes. Histopathology of ovarian surgical specimens confirmed poorly differentiated ovarian cancer. This case highlights the utility of FDG PET/CT in evaluating pericardial effusion of unknown etiology and introduces the potential role of FAPI PET/CT in such scenarios.

Comparative Evaluation of 68Ga-FAPI-04 PET for Initial N and M Staging in Gastric Cancer: A Study Against Histopathology and Contrast-Enhanced CT

Purpose: To evaluate the efficiency of 68Ga-FAPI-04 PET (PET/MRI or PET/CT) for N and M staging in gastric carcinoma and compare outcomes with histopathology and contrast-enhanced computed tomography (CECT). Patients and Methods: Patients with gastric carcinoma who had undergone 68Ga-FAPI-04 PET/MRI or PET/CT before treatment were retrospectively enrolled. Histopathology post lymphadenectomy was the gold standard for N staging, while histopathology and follow-up data were the reference for overall outcomes. The diagnostic efficiency of 68Ga-FAPI-04 PET for detecting regional lymph node involvement and distant metastases was compared to that of CECT. Results: Sixty-two patients were enrolled. In 18 patients who underwent 68Ga-FAPI-04 PET/MRI and lymphadenectomy, 532 lymph nodes were dissected. 68Ga-FAPI-04 PET/MRI showed similar sensitivity, specificity, and accuracy compared to CECT (28.3% vs. 23.2%, 99.8% vs. 99.3%, and 86.5% vs. 85.2%, all P > 0.05). Fifty-five patients had regional lymph node metastasis, 68Ga-FAPI-04 PET exhibited comparable diagnostic efficiency to CECT, with sensitivity of 83.6% versus 87.3%, specificity of 100% versus 85.7%, accuracy of 85.5% versus 87.1% (all P > 0.05). Excluding 3 patients with only abdominal CECT, 32 out of 59 patients had distant metastasis, with no significant differences in sensitivity, specificity, and accuracy between 68Ga-FAPI-04 PET and CECT based on patient (100% vs. 87.5%, 92.6% vs. 96.3%, and 96.6% vs. 91.5%, all P >0.05). Notably, 68Ga-FAPI-04 PET outperformed CECT in detecting peritoneal, distant lymph nodes, bone, liver, and ovarian metastases by visualizing more lesions or greater lesion extent. Conclusions: 68Ga-FAPI-04 PET exhibits comparable diagnostic performance to CECT for patient-based N staging and M staging of gastric cancer. However, it surpasses CECT in visualizing distant metastases.

Functional Imaging in 2 Rare Cases of Struma Ovarii With Contrasting Features

We present 2 cases, one with benign struma ovarii that was diagnosed preoperatively on Tc-99m and I-131 scans and another of malignant struma ovarii with peritoneal metastases that were detected postoperatively on 18F-FDG PET/CT and post-radioiodine (I-131) therapy scans. Benign struma ovarri had a rare occurrence of coexisting Graves’ disease, while malignant struma ovarii demonstrated rare peritoneal involvement on functional imaging. Even though rare, struma ovarii can present with contrasting features and may require extensive workup, including functional scans and radioiodine therapy as shown in these cases.

18F-FDG PET/CT in Epithelioid Malignant Peripheral Nerve Sheath Tumor of the Vagina

We describe MRI and FDG PET/CT findings of vaginal epithelioid malignant peripheral nerve sheath tumor in a 60-year-old woman. The patient presented with irregular vaginal bleeding. On MRI, the mass appeared hypointense on T1WI and hyperintense on T2WI, demonstrating diffusion restriction and enhancement. 18 F-FDG PET/CT revealed a solitary vaginal mass with intense FDG uptake. Surgical pathology confirmed the diagnosis of epithelioid malignant peripheral nerve sheath tumor.

Unilateral Nodular Adrenal Hyperplasia Mimicking Endometrial Cancer Metastasis on 18F-FDG PET/CT After Immunochemotherapy

Unilateral nodular adrenal hyperplasia after immunochemotherapy is extremely rare. We reported a 70-year-old woman with endometrial cancer who underwent 18F-FDG PET/CT to evaluate the immunochemotherapy response. Compared with the baseline, follow-up PET/CT revealed a newly hypermetabolic nodule in the left adrenal gland, initially suspected to be metastatic. However, surgical resection and pathology confirmed it as adrenal hyperplasia. This case highlights the importance of recognizing unilateral nodular adrenal hyperplasia as a rare imaging finding mimicking metastasis following immunochemotherapy, which should be considered in the differential diagnosis.

FDG PET/CT Image of Extrarenal Wilms Tumor of Cervix

Wilms tumor is a rare type of cancer that mainly affects children. It’s the most common cancer of the kidneys in children. Although it is usually seen under the age of 3, it can also be diagnosed at older ages. Extrarenal Wilms tumor (ERWT) is very rare, comprising <1% of all Wilms tumor cases. It is most commonly seen in the retroperitoneum and pelvic region and has been reported in a limited number of patients in the literature. This report presents a patient with ERWT of the cervix who underwent FDG PET/CT imaging.

Extrarenal Uptake of 99mTc-DMSA in Uterine Leiomyoma

We present a DMSA renal scan finding in a 42-year-old woman with new flank pain. Ultrasonography revealed hydronephrosis and renal stones. A 99mTc-DMSA renal scan showed global cortical loss and multiple cortical defects in the left kidney, with an incidental large zone of uptake in the abdominopelvic region initially suspected as bladder. SPECT/CT imaging clarified this as a large leiomyoma which is proved in permanent pathology. This case highlights the importance of advanced imaging to distinguish physiological organs from tumoral masses and avoid misdiagnosis.

Extrauterine Endometrial Stromal Sarcoma Mimicking Colorectal Cancer With Metastases

Abstract Extrauterine endometrial stromal sarcoma (EESS) is extremely rare, especially with the colorectum involvement. We describe 18F-FDG PET/CT findings of EESS in the sigmoid colon and rectum in a 46-year-old woman who complained diarrhea. 18F-FDG PET/CT revealed multiple hypermetabolic lesions in the abdomen and pelvis, including the sigmoid colon and rectum. Therefore, colorectal cancer with metastases was initially suspected; however, ultimately low-grade EESS was pathologically confirmed. Widespread EESS with intestine involvement revealed by 18F-FDG PET/CT should be carefully distinguished from colorectal cancer with metastases.

Imaging of Tumor Hypoxia With 18F-EF5 PET/MRI in Cervical Cancer

Purpose of the Report The aim of this study was to evaluate the distribution of hypoxia using 18F-EF5 as a hypoxia tracer in cervical cancer patients with PET/MRI. We investigated the association between this 18F-EF5-PET tracer and the immunohistochemical expression of endogenous hypoxia markers: HIF1α, CAIX, and GLUT1. Patients and Methods Nine patients with biopsy-proven primary squamous cell cervix carcinoma (FIGO 2018 radiological stages IB1–IIIC2r) were imaged with dual tracers 18F-EF5 and 18F-FDG using PET/MRI (Int J Gynaecol Obstet. 2019;145:129–135). 18F-EF5 images were analyzed by calculating the tumor-to-muscle ratio to determine the hypoxic tissue (T/M ratio >1.5) and further hypoxic subvolume (HSV) and percentage hypoxic area. These 18F-EF5 hypoxic parameters were correlated with the size and localization of tumors in 18F-FDG PET/MRI and the results of hypoxia immunohistochemistry. Results All primary tumors were clearly 18F-FDG and 18F-EF5 PET positive and heterogeneously hypoxic with multiple 18F-EF5–avid areas in locally advanced cancer and single areas in clinically stage I tumors. The location of hypoxia was detected mainly in the periphery of tumor. Hypoxia parameters 18F-EF5 max T/M ratio and HSV in primary tumors correlated independently with the advanced stage (P = 0.036 and P = 0.040, respectively), and HSV correlated with the tumor size (P = 0.027). The location of hypoxia in 18F-EF5 imaging was confirmed with a higher hypoxic marker expression HIF1α and CAIX in tumor fresh biopsies. Conclusions The 18F-EF5 imaging has promising potential in detecting areas of tumor hypoxia in cervical cancer.

Superiority of 18F-FAPI PET/CT to 18F-FDG PET/CT in the Evaluation of Synchronous Renal and Uterine PEComa

A 24-year-old woman presented with abdominal distension for 1 week. Abdominal contrast-enhanced CT showed 2 abnormal enhanced lesions in uterine fundus and in the lower pole of the right kidney, suggesting a probability of malignancies. As part of a clinical trial, the patient underwent both 18 F-FAPI and 18 F-FDG PET/CT to assess the malignancy of the lesions. Compared with 18 F-FDG PET/CT, 18 F-FAPI PET/CT demonstrated more intense and extensive tracer uptake in these lesions. Finally, pathologic analysis confirmed perivascular epithelioid cell tumors.

Malignant Extrarenal Rhabdoid Tumor of the Vagina on FDG PET/CT

Abstract Malignant rhabdoid tumor is an aggressive neoplasm commonly arising from the kidney during infancy and childhood. Extrarenal forms of this tumor are relatively rare and have been reported in several extrarenal sites including central nervous system, liver, bladder, vulva, and head and neck. Hereby, we present FDG PET/CT findings of malignant extrarenal rhabdoid tumor originating from the vagina in an 8-year-old girl.

Paraganglioma From Vaginal Wall Revealed by 131I-MIBG Scan

Abstract Vaginal paraganglioma is very rare. Most patients first presented irregular heavy menses and abnormal vaginal bleeding. The accurate diagnosis can only be made pathologically. Here we report a case of paraganglioma arising from vaginal wall in a 44-year-old woman who only presented catecholamine-related symptoms. The lesion had negative 99mTc-HYNIC-TOC (hydrazinonicotinyl-Tyr3-octreotide) activity but positive on 131I MIBG scan. Paraganglioma was highly suspected, which was confirmed by pathological and immunohistochemical findings after surgical resection of the lesion.

Recurrent Ovarian Cancer Presenting as a Solitary Chest Wall Metastasis Revealed by FDG PET/CT

Abstract A 55-year-old woman who was diagnosed with ovarian cancer 4 years ago complained of back pain for 1 month, and the CA-125 level was elevated. FDG PET/CT was then performed for restaging, and the images revealed a hypermetabolic mass in the right posterior chest wall. Postsurgical pathology confirmed metastasis from ovarian cancer.

Intense 68Ga-FAPI-46 Activity in Lesions of Recurrent Ovarian Clear Cell Carcinoma That Were Negative on FDG PET/CT Study

Abstract A 55-year-old woman with recurrent ovarian clear cell carcinoma who underwent complete surgical staging and completed chemotherapy session approximately 7 months before. She presented with increased CA-125 levels. 68Ga-FAPI-46 PET showed significantly higher tumor-to-background contrast of recurrent intra-abdominal node metastases and distant metastases, which were undetectable in the 18F-FDG PET. These findings changed the patient management. Larger studies with comparisons with other imaging modalities are required to validate the diagnostic performance.

18F-FDG PET/CT in Bilateral Breasts Metastasis From Ovarian Carcinoma

Abstract Ovarian carcinomas generally metastasize within the peritoneal cavity due to exfoliation of malignant cells from primary tumor. Metastasis to the breasts is an unusual event and may mimic primary neoplastic disease. Usually, breast metastasis presents as a single isolated, well-circumscribed soft tissue lesion, and serous papillary carcinoma is the most common type of ovarian tumor that can metastasize to the breast. Concurrent bilateral breast metastasis is rare event. We present a follow-up case of metastatic carcinoma ovary, demonstrating FDG-avid soft tissue density masses in the bilateral breast parenchyma along with bilateral axillary lymphadenopathy, biopsy of which revealed metastatic deposits from carcinoma ovary.

Isolated Vaginal Recurrence of Urothelial Bladder Cancer on FDG PET/CT

A 58-year-old woman who underwent partial cystectomy for a high-grade invasive urothelial carcinoma of the left lateral bladder wall 11 months ago was referred of FDG PET/CT scan to evaluate a possible vaginal malignancy detected on a follow-up pelvic MRI 5 days ago. FDG PET/CT showed intense activity of the vaginal mass indicating malignancy and no other lesion suspicious for malignancy. A diagnosis of metastatic high-grade urothelial carcinoma of the vagina was made after removal of the mass.

The Association of Tumor Burden by 18F-FDG PET/CT and Survival in Vulvar Carcinoma

Purpose The aim of this study was to assess the impact of 18F-FDG PET/CT metabolic parameters obtained at initial staging of vulva carcinoma on survival in women with and without HIV infection. Patients and Methods 18F-FDG PET/CT images of women with vulva cancer who are planned for definitive therapy were analyzed. SUVmax, SUVmean, MTV, and total lesion glycolysis (TLG) as well as whole-body MTV and whole-body TLG were computed. Results Twenty-five women were included with a mean age of 43.44 ± 10.32. The majority of the patients were HIV infected with a median CD4 count of 444.00 cells/mm3. The HIV-infected women are younger at diagnosis than their HIV-uninfected counterparts. All patients presented with inguinofemoral lymph node involvement, whereas half the patients had pelvic nodal metastasis. All the patients with distant visceral or skeletal metastasis were HIV infected. The lungs were the most common site of distant metastasis. When comparing the SUVmax, SUVmean, MTV, TLG, wbMTV, and wbTLG between HIV-infected and HIV-uninfected patients, we did not find statistical differences. Twelve patients (48%) were upstaged to metastatic disease. Seven patients had died at the time of analysis. The wbMTV and wbTLG were significantly higher in nonsurvivors than survivors. Conclusions 18F-FDG PET/CT improves initial staging of squamous cell carcinoma among women with and without HIV infection. The whole-body tumor burden assessed by 18F-FDG PET metabolic metrics did not differ between HIV-infected and HIV-uninfected women. A higher whole-burden tumor burden is associated with a higher risk of mortality among women with vulva cancer.

High-Specific-Activity 131I-MIBG for the Treatment of Advanced Pheochromocytoma and Paraganglioma

Background Metastatic pheochromocytomas and paragangliomas (MPPGLs) are rare tumors with limited treatment options. High-specific-activity 131I-MIBG (HSA-131I-MIBG) is the only US Food and Drug Administration–approved therapy for MPPGL. We studied the efficacy and safety of HSA-131I-MIBG in routine clinical practice. Patients and Methods The primary endpoints were objective response rate (ORR) and disease control rate (DCR). Secondary endpoints were duration of response, blood pressure control, safety, overall and progression-free survival rates, MIBG uptake, and correlations with genetic background. Results The study included 25 patients. Twenty-four patients had distant metastases, 17 (68%) had hormonally active tumors, and 13 (52%) had previously received antineoplastic treatment. In 24 evaluable patients, the ORR was 38%, including 2 patients with complete response, and the DCR was 83%; median time to response was 12.5 months (95% confidence interval, 4.6–25.1). Twelve patients had sporadic disease, among whom the ORR was 25% and DCR was 83%. Twelve patients had hereditary disease (SDHB, VHL, RET); among these, the ORR was 50%, and DCR was 83%. Plasma metanephrines normalized in 30% of patients and improved by greater than 50% in 46%. Sixteen patients had hormonally active tumors and hypertension; in 9 (56%) of these, blood pressure normalized, leading to discontinuation of antihypertensive therapy. The most common adverse events were grades 1–2 nausea/vomiting and transient bone marrow suppression. One patient developed premature ovarian failure. Reversible grades 3–4 myelosuppression were seen in 7 patients (28%). One patient had fatal pneumonitis. Conclusions HSA-131I-MIBG is associated with a high DCR in patients with MPPGL, regardless of underlying genetic mutation.

Cutaneous Metastasis of Ovarian Cancer on 68Ga-FAPI PET/CT

Abstract Ovarian cancer with cutaneous metastases is quite rare. We report the findings of cutaneous metastases from ovarian cancer on 68Ga-FAPI PET/CT imaging. A 53-year-old woman with cutaneous metastases from ovarian cancer was enrolled in 68Ga-FAPI PET/CT clinical trial. The images showed intense FAPI activity in the known cutaneous metastases.

Struma Ovarii With Extensive Peritoneal Implants Metastasis Revealed by 99mTcO4 SPECT/CT

Abstract Struma ovarii is a rare form of ovarian teratoma composed entirely or mainly of mature thyroid tissue. A 55-year-old woman with persistent hypogastric pain for 4 months was admitted to our hospital. She had undergone resection of struma ovarii 4 years ago. Contrast-enhanced CT shows multiple significantly enhanced nodules scattered in the abdominopelvic cavity. Pathological examination of the nodule in the left pararenal region demonstrated thyroid-like follicular epithelium. Herein, we present the 99mTcO4 whole-body scintigraphy SPECT/CT findings of a case of struma ovarii with extensive peritoneal implants metastasis. Then, she was treated with total thyroidectomy and 131I therapy.

Unusual Presence of Synchronous Primary Ovarian and Thyroid Extranodal Non-Hodgkin Lymphoma Without Lymph Node Involvement

Abstract Extranodal lymphomas without lymph node involvement are rarely observed and create diagnostic challenges. We present the case of a 33-year-old woman who was admitted with abdominal swelling. Ultrasonography findings suggested bilateral ovarian masses. 18F-FDG PET/CT revealed intense uptake on the bilateral pelvic mass and thyroid gland. Following excisional surgery and thyroid fine-needle aspiration biopsy, the patient was diagnosed with diffuse large B-cell lymphoma. This case is exceptionally rare, as it presents 2 synchronous extranodal involvements in the ovaries and the thyroid gland independently while not presenting any lymph node activity, which has not been reported before.

18F-FDG PET/CT Findings of Ovarian Myxoid Chondrosarcoma

Abstract Ovarian myxoid chondrosarcoma is a rare and aggressive tumor. We present 18F-FDG PET/CT findings of ovarian myxoid chondrosarcoma. The images not only demonstrated a pelvic mass with increased FDG uptake, but also a mass with increased FDG uptake in the right lower abdominal wall. Ovarian malignancy with abdominal wall metastases was suspected. An extraskeletal myxoid chondrosarcoma was diagnosed histopathologically after the mass excision.

18F-FDG and 68Ga-FAPI-04 PET/CT in Evaluating Clear-Cell Endometrial Cancer

Abstract A 60-year-old woman diagnosed with clear cell endometrial carcinoma received neoadjuvant chemotherapy. However, the patient was inoperable and referred to our clinic to evaluate the extent of the disease. The patient underwent 18FDG PET/CT and 68Ga-FAPI (fibroblast activated protein inhibitor)-04 PET/CT scans. 68Ga-FAPI-04 PET/CT outperformed 18FDG PET/CT demonstrating higher uptake in the metastatic lesions.

18F-FDG PET/CT Findings of Tibia Metastasis From Endometrial Adenocarcinoma

Abstract Bone metastases from endometrial carcinoma are rare, especially when the bone is the sole metastatic site. A 55-year-old woman with a history of endometrial carcinoma was referred for FGD PET/CT scan due to pain in the left knee. The images showed that multiple lesions with intense activity were detected in the left tibia. Histopathological examination and immunohistochemistry of the left tibial lesion confirmed metastases from the endometrial adenocarcinoma.

Synchronous Endometrial Cancer Detected on 68Ga-DOTATATE PET/CT

Abstract A 50-year-old woman with history of metastatic neuroendocrine tumor underwent a follow-up PET/CT with 68Ga-DOTATATE. An enlarged uterus with diffuse increased uptake warranted further investigation with an MRI that showed mass-like thickening of the endometrium, T2 hyperintensity, lobulated contour, and invasion of more than 50% of the myometrium. Biopsy revealed endometrial carcinoma with mucinous features. Mild to moderate uptake of the 68Ga-DOTATATE by the uterus can be a normal physiological finding; however, it should prompt further investigation, particularly in a postmenopausal woman with concerning imaging or clinical findings.

Intranodular Thyroid Metastasis of a Large Cell Neuroendocrine Carcinoma of the Endometrium

Abstract A 64-year-old woman underwent initial 18F-FDG PET/CT staging for a suspicious endometrial mass, which showed high uptake in the endometrial mass and a focal uptake in a known left thyroid nodule. Histology revealed a high-grade large cell neuroendocrine carcinoma of the endometrium with FIGO (International Federation of Gynecology and Obstetrics) stage Ib. Further explorations revealed a synchronous thyroid metastasis. Patient then received adjuvant immunochemotherapy. This case showed a potential pitfall in the initial assessment of this rare and aggressive malignancy on which the therapeutic approach greatly depends.

68Ga-Prostate-Specific Membrane Antigen PET/CT in Endometrial Cancer: A Preliminary Report

Purpose of the Report Endometrial cancer is the most common gynecological cancer. Prostate-specific membrane antigen (PSMA) is expressed in prostate cancer cells but can be found in other cancers, such as endometrial cancer, during angiogenesis. The aim of this prospective pilot study was to evaluate the feasibility of using 68Ga-PSMA-11 PET/CT in endometrial cancer patients before surgical treatment. Patients and Methods Seven women with a mean age of 58 ± 7.9 years were included in the study. All patients underwent standard imaging studies involving transvaginal ultrasound, ceCT scans of the chest and abdomen, and MRI as qualified for surgery. Additionally, PET/CT was performed on a Siemens Biograph scanner 60 minutes after the injection of 2 MBq/kg 68Ga-PSMA-11. Results Six of 7 patients had positive 68Ga-PSMA-11 PET/CT images, and histopathology confirmed endometrial cancer. One patient also exhibited uptake in the left ovary, and final histopathology revealed a hemorrhagic cyst. Lymph node involvement was further confirmed after ceCT fusion with 68Ga-PSMA-11. The consensus of histopathological staging of endometrial cancer and ceCT was 4/7, that of MR was 6/7, and that of 68Ga-PSMA-11 PET/CT was 5/7. All methods were consistent in terms of staging in 3/7 patients. Conclusions The initial experience showed the possibility of using 68Ga-PSMA-11 in endometrial cancer patients. However, prospective large studies are needed to explore the real diagnostic role of radiolabelled PSMA in this field. This study was approved by the Ethical Committee of the Medical University of Warsaw (KB/2/A/2018).

Hybrid PET/MRI in Staging Endometrial Cancer

Aim The assessment of deep myometrial invasion (MI) and lymph node involvement is of utmost importance in the preoperative staging of endometrial cancer (EC). Imaging parameters derived respectively from MRI and PET have shown good predictive value. The main aim of the present study is to assess the diagnostic performance of hybrid 18 F-FDG PET/MRI in EC staging, with particular focus on MI and lymphnodal involvement detection. Patients and Methods Prospective monocentric study including 35 patients with biopsy-proven EC undergoing preoperative 18 F-FDG PET/MRI (December 2018–March 2021) for staging purpose. Histological examination was the reference standard. PET (SUV max , SUV mean with a threshold of 40% of SUV max –SUV mean40 , metabolic tumor volume, total lesion glycolysis) and MRI (volume index [VI], total tumor volume, tumor volume ratio [TVR], mean apparent diffusion coefficient, minimum apparent diffusion coefficient) parameters were calculated on the primary tumor, and their role in predicting EC risk group, the presence of lymphovascular space invasion (LVSI), and MI was assessed. Receiver operating characteristics analysis was used to assess the predictive value of PET and MRI parameters on EC characteristics. Results Patients' median age was 66.57 years (SD, 10.21 years). 18 F-FDG PET/MRI identified the primary tumor in all patients. Twenty-two of 35 patients had high-risk EC and 13/35 low-risk disease; 13/35 presented LVSI, 22/35 had deep MI at histological examination, and 13/35 had p53 hyperexpression. PET/MRI was able to detect lymphnodal involvement with high accuracy and high specificity (sensitivity of 0.8571, specificity of 0.9286, accuracy of 0.9143), also showing a high negative predictive value (NPV) for lymphnodal involvement (NPV of 0.9630, positive predictive value [PPV] of 0.7500). The assessment of deep MI using PET/MRI correctly staged 27 patients (77.1%; sensitivity of 0.7273, specificity of 0.8462, accuracy of 0.7714), with also a good PPV (PPV of 0.8889, NPV of 0.647). MRI-derived total tumor volume, VI, and TVR were significant in predicting EC groups (high-risk vs low-risk patients) ( P = 0.0059, 0.0235, 0.0181, respectively). MRI-derived volume, VI, TVR, and PET-derived metabolic tumor volume and total lesion glycolysis were able to predict LVSI ( P = 0.0023, 0.0068, 0.0068, 0.0027, 0.01394, respectively). Imaging was not able to predict grading, presence of deep MI, nor hyperexpression of p53. Conclusions 18 F-FDG PET/MRI has good accuracy in preoperative staging of EC; PET and MRI parameters have synergic role in preoperatively predicting LVSI, with MRI parameters being also predictive for EC risk group.

Metastatic Small Cell Neuroendocrine Carcinoma of Endometrium

Abstract Primary small cell neuroendocrine carcinoma of endometrium is very rare and aggressive carcinoma. Most patients present with metastases at the time of diagnosis and have very poor prognosis. Only very few cases are reported in literature. Here we present a case of 67-year-old woman, who on evaluation for mild pain abdomen was subsequently diagnosed to have metastatic small cell neuroendocrine carcinoma of endometrium on PET/CT scan and biopsy.

PET Imaging of Estrogen Receptors for Gynecological Tumors

Abstract In the past few decades, PET with 18F-FDG has been used for the diagnosis of gynecological malignancies and is considered to be superior to conventional imaging methods in diagnostic accuracy for detecting metastatic lesions and local recurrence and in evaluating the treatment response. On the other hand, several gynecological tumors, such as endometrial cancer and leiomyoma, and breast cancer are estrogen-dependent, in which estrogen is essential for their development and progression. 18F-FES is an 18F-labeled compound of estradiol, the most bioactive type of estrogen, and 18F-FES PET has been well-established for diagnosis, staging, and posttherapeutic follow-up in patients with estrogen receptor–positive breast cancer. Compared with in vitro assessment of tumor biopsy material, PET imaging has the advantages of being able to measure in vivo tumor behavior, characterize the entire tumor burden, and capture the heterogeneity of the tumor phenotype. In this article, we review the phenotyping of estrogen-related gynecological tumors other than breast cancer using 18F-FES PET and demonstrate the additional value of 18F-FES PET to 18F-FDG PET in their diagnosis and prognostication. Moreover, promising PET tracers other than 18F-FES and 18F-FDG for the evaluation of estrogen-related gynecological tumors are introduced.

Solitary Splenic Metastasis From Endometrial Carcinoma Revealed on FDG PET/CT

Abstract Solitary splenic metastasis from endometrial carcinoma is rare. We report a case of imaging findings of solitary splenic metastasis in a 53-year-old woman who underwent resection surgery of endometrial carcinoma of uterus 1 year ago. On FDG PET/CT, it presented as a solitary soft tissue mass with an SUVmax of 18.44. The postoperative pathology supported metastasis from endometrial carcinoma.

Rare Presentation of Late Complications After Undiagnosed Perforated Appendicitis Mimicking Recurrent Endometrial Carcinoma on 18F-FDG PET/CT

Abstract Acute appendicitis is one of the most common causes of acute abdominal pain. Undiagnosed or untreated appendicitis can lead to serious complications. The most frequent complication of acute appendicitis is perforation with subsequent formation of a localized periappendiceal abscess or diffuse bacterial peritonitis. Late occurring complications following undiagnosed appendix perforation can pose a diagnostic challenge due to uncharacteristic clinical and imaging presentation. Herein, we describe late findings of undiagnosed perforated appendicitis that on 18F-FDG PET/CT mimicked recurrent endometrial carcinoma disease in a 67-year-old woman.

Incidental Finding of Endometrioid Adenocarcinoma of the Ovary on 131I Whole-Body Scan

Abstract A 57-year-old woman was referred for radioactive iodine therapy 12 weeks after completion thyroidectomy and left modified radical neck dissection for pT2N1Mx follicular variant papillary thyroid carcinoma. After 4 weeks of l-thyroxine withdrawal, stimulated serum thyroglobulin level was less than 0.1 ng/mL with positive thyroglobulin antibody. Posttherapy 131I scintigraphy with SPECT/CT of the head and abdominopelvic region showed thyroid residual in the neck, occipital bone metastasis, and heterogenous tracer uptake in a large peritoneal mass, likely arising from the left ovary. Left salpingo-oophorectomy was performed, and histopathologic examination revealed endometrioid carcinoma of left ovary.

Inflammatory Myofibroblastic Tumor of the Liver Mimicking Metastasis on 18F-FDG PET/CT

Abstract A 62-year-old woman with history of stage III endometrial cancer was found to have a small enhancing liver lesion on follow-up abdominal CT and MRI, suspicious for metastasis. Subsequent 18F-FDG PET/CT was performed, demonstrating intense uptake within the liver lesion, consistent with metastasis. Subsequently, laparoscopic wedge liver lesion resection was performed. Histopathologic examination confirmed the diagnosis of inflammatory myofibroblastic tumor (IMT) with predominant inflammatory cells. Although solitary liver IMTs are rare occurrences with imaging features overlapping with malignancy, IMT should be considered in the differential diagnosis of suspicious liver lesions, especially when the pattern of spread is unusual.