Nuklearmedizin - NuclearMedicine

Cervical Cancer Metastasis to the Stomach Masquerading as Primary Gastric Cancer: A Case Report of a Rare Metastasis Detected via 18F-FDG PET/CT

Radiomics Analysis of Multiparametric PET/MRI for N- and M-Staging in Patients with Primary Cervical Cancer

Purpose The aim of this study was to investigate the potential of multiparametric 18F-FDG PET/MR imaging as a platform for radiomics analysis and machine learning algorithms based on primary cervical cancers to predict N- and M-stage in patients. Materials and Methods A total of 30 patients with histopathological confirmation of primary and untreated cervical cancer were prospectively enrolled for a multiparametric 18F-FDG PET/MR examination, comprising a dedicated protocol for imaging of the female pelvis. The primary tumor in the uterine cervix was manually segmented on post-contrast T1-weighted images. Quantitative features were extracted from the segmented tumors using the Radiomic Image Processing Toolbox for the R software environment for statistical computing and graphics. 45 different image features were calculated from non-enhanced as well as post-contrast T1-weighted TSE images, T2-weighted TSE images, the ADC map, the parametric Ktrans, Kep, Ve and iAUC maps and PET images, respectively. Statistical analysis and modeling was performed using Python 3.5 and the scikit-learn software machine learning library for the Python programming language. Results Prediction of M-stage was superior when compared to N-stage. Prediction of M-stage using SVM with SVM-RFE as feature selection obtained the highest performance providing sensitivity of 91 % and specificity of 92 %. Using receiver operating characteristic (ROC) analysis of the pooled predictions, the area under the curve (AUC) was 0.97. Prediction of N-stage using RBF-SVM with MIFS as feature selection reached sensitivity of 83 %, specificity of 67 % and an AUC of 0.82. Conclusion M- and N-stage can be predicted based on isolated radiomics analyses of the primary tumor in cervical cancers, thus serving as a template for noninvasive tumor phenotyping and patient stratification using high-dimensional feature vectors extracted from multiparametric PET/MRI data. Key points:

18F-FDG PET/CT imaging of vulva cancer recurrence: A comparison of PET-derived metabolic parameters between women with and without HIV infection

AbstractObjective To assess the patterns of recurrence of vulva cancer on 18F-FDG PET/CT and to compare the 18F-FDG PET metabolic metrics in patients with and without Human Immunodeficiency Virus (HIV).Methods Maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumour volume (MTV and total lesion glycolysis (TLG) were obtained on Flourine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) images of women referred with suspected or confirmed vulva cancer recurrence. We compared HIV-infected and HIV-uninfected patients regarding pattern disease recurrence, age at diagnosis, and the PET-derived metabolic indices.Results We analyzed 33 patients with a mean age 50.76 ± 15.78 including 21 HIV-infected women. The majority of patients (94 %) had squamous cell carcinoma and 84.85 % were Blacks. Of the HIV-infected individuals, the median CD4 count was 526.0 cells/mm3 (IQR: 379.0–729.0). HIV infected patients were younger than the HIV uninfected at the time of diagnosis: 40.50 ± 8.87 vs 66.54 ± 9.71 respectively, p < 0.001. We found a local (vulvar) recurrence rate of 75.8 %. Nodal pelvic recurrences were higher in the HIV-infected patients than in the HIV uninfected patients (70 % vs 30 %, p = 0.027). Three patients had distant metastasis and all three were HIV-infected. There was a higher whole-body MTV and TLG among HIV-infected women compared with HIV-uninfected women, 103.39 vs 17.58 and 852.64 vs 101.79, respectively (p < 0.05 for both).Conclusion HIV-infected women are diagnosed with vulva cancer at a younger age. HIV-infected patients had a higher rate of pelvic lymph node recurrence. There is a higher tumor burden at vulva cancer recurrence among women with HIV infection.

Comparison of semiquantitative metabolic parameters of the primary tumor obtained in PET/CT with 18F-FDG and 18F-FLT in patients with cervical cancer

Abstract Aim The aim of the study was to compare semiquantitative metabolic parameters of primary tumor assessed in vivo in 18F-FDG- and 18F-FLT in cervical cancer patients. Material & Methods 39 patients with histologically confirmed cervical cancer underwent PET/CT scans acquired on separate days 60 min after i. v. injection of 364 ± 75 MBq of 18F-FDG and 259 ± 40 MBq of 18F-FLT. The reconstructed PET images were evaluated using a dedicated workstation for primary tumor semiquantitative parameters: SUVmax, MTV, TLG (for 18F-FLT-TLP) and heterogeneity (AUC-CSH). Wilcoxon-Mann-Whitney test and ROC curves were used for statistical analysis. Based on data from the local cancer registry and 3y- to -5y follow up patients were divided into 2 groups with regard to prognosis. Also differences between histopathological type and FIGO classification in two tracers were assessed. Results Depending on PET/CT results, patients were divided into 3 groups: group 1 with disease limited only to the cervix, group 2 with disease limited to the cervix and iliac lymph nodes, and group 3 with disseminated disease. Statistically significant differences were found between keratinizing and non-keratinizing SCC in SUVmax (p = 0.03) and AUC-CSH (p = 0.04) only in 18F-FLT-PET/CT. Following cut-off values for nodal involvement in SUVmax, MTV, TLG/TLP and AUC-CSH were calculated using ROC curves: 13.5, 39.22, 255.94, 0.59 respectively for 18F-FDG and 12.1, 37.59, 140.01, 0.46 respectively for 18F-FLT. Higher values in both tracers in MTV and TLG/TLP were found in a group with worse prognosis. Conclusion This preliminary study suggests that higher values in MTV and TLG/TLP in both tracers might be associated with worse outcome in cervical cancer patients.

Morbidity and quality of life in patients with vulvar cancer after inguinal sentinel lymphadenectomy compared to radical inguinofemoral lymphadenectomy

Abstract Aim Probability of survival of patients with vulvar cancer directly depends on the lymph node status. Surgery of lymph nodes can be performed as radical inguinofemoral lymphadenectomy or in cases with certain conditions as sentinel lymph node surgery. The aim of this study is to obtain an overview of the intervention-related morbidity and quality of life in patients with vulvar carcinoma after lymphadenectomy. Methods Quality of life and morbidity was compared between patients who underwent radical inguinofemoral lymphadenectomy with those who underwent sentinel lymph node surgery. Results All recorded postoperative complications occur more frequently in the non-sentinel group, Significant difference was shown for the occurrence of lymphedema (p-value = 0.024) and sensitivity loss (p-value = 0.024). Recurrence of disease was more frequent in the non-sentinel group (38 % vs. 20 %, p = 0.621, n.s.) and satisfaction with groin surgery is slightly higher in the sentinel group (94 % vs. 89 %, p = 1.000, n.s.). Conclusion We could demonstrate a significantly lower morbidity of sentinel lymphadenectomy compared to conventional inguinofemoral lymphadenectomy while maintaining the same oncological safety. The low morbidity of sentinel- lymphadenectomy does not seem to influence the postoperative quality of life significantly. However, recording of the individual burden of lymphadenectomy by questionnaires should be optimized.

PET Parameters are Useful in Predicting Endometrial Cancer Risk Classes and Prognosis

Abstract Aim We investigate the role of preoperative PET parameters to determine risk classes and prognosis of endometrial cancer (EC). Methods We enrolled 81 patients with EC who underwent preoperative F-18 FDG PET/CT. PET parameters (SUVmax, SUVmean, MTV, TLG), grade, histology and size of the primary tumor, stage of the disease, the degree of myometrial invasion (MI), and the presence of lymphovascular invasion (LVI), cervical invasion (CI), distant metastasis (DM) and lymph node metastasis (LNM) were recorded. The relationship between PET parameters, clinicopathological risk factors and overall survival (OS) was evaluated. Results The present study included 81 patients with EC (mean age 60). Of the total sample, 21 patients were considered low risk (endometrioid histology, stage 1A, grade 1 or 2, tumor diameter < 4 cm, and LVI negative) and 60 were deemed high risk. All of the PET parameters were higher in the presence of a high-risk state, greater tumor size, deep MI, LVI and stage 1B-4B. MTV and TLG values were higher in the patients with non-endometrioid histology, CI, grade 3 and LNM. The optimum cut-off levels for differentiating between the high and low risk patients were: 11.1 for SUVmax (AUC = 0.757), 6 for SUVmean (AUC = 0.750), 6.6 for MTV(AUC = 0.838) and 56.2 for TLG(AUC = 0.835). MTV and TLG values were found as independent prognostic factors for OS, whereas SUVmax and SUVmean values were not predictive. Conclusions The PET parameters are useful in noninvasively differentiating between risk groups of EC. Furthermore, volumetric PET parameters can be predictive for OS of EC.