Investigator

Remi A. Nout

Leiden University

RANRemi A. Nout
Papers(7)
Clinical Behavior and…Prognostic Integrated…Margin and robustness…Automated planning of…Acute and long-term t…Closing the gap for c…Afterloader integrate…
Collaborators(10)
Jérémy GodartMischa S HoogemanNanda HorewegInger-Karine Kolkman-…Carien CreutzbergRobin StraathofViktor H. KoelzerW Glenn McCluggageAlicia León-CastilloAmy Jamieson
Institutions(7)
Leiden UniversityErasmus University Ro…Erasmus University Ro…Delft University Of T…Universität ZürichBelfast Health And So…University Of British…

Papers

Clinical Behavior and Molecular Landscape of Stage I p53-Abnormal Low-Grade Endometrioid Endometrial Carcinomas

Abstract Purpose: The clinical significance of the p53-abnormal (p53abn) molecular subtype in stage I low-grade endometrioid endometrial carcinoma (EEC) is debated. We aimed to review pathologic and molecular characteristics, and outcomes of stage I low-grade p53abn EEC in a large international cohort. Experimental Design: Previously diagnosed stage I p53abn EC (POLE–wild-type, mismatch repair–proficient) low-grade EEC from Canadian retrospective cohorts and PORTEC-1&2 trials were included. Pathology review was performed by six expert gynecologic pathologists blinded to p53 status. IHC profiling, next-generation sequencing, and shallow whole-genome sequencing was performed. Kaplan–Meier method was used for survival analysis. Results: We identified 55 stage I p53abn low-grade EEC among 3,387 cases (2.5%). On pathology review, 17 cases (31%) were not diagnosed as low-grade EEC by any pathologists, whereas 26 cases (47%) were diagnosed as low-grade EEC by at least three pathologists. The IHC and molecular profile of the latter cases were consistent with low-grade EEC morphology (ER/PR positivity, patchy p16 expression, PIK3CA and PTEN mutations) but they also showed features of p53abn EC (TP53 mutations, many copy-number alterations). These cases had a clinically relevant risk of disease recurrence (5-year recurrence-free survival 77%), with pelvic and/or distant recurrences observed in 12% of the patients. Conclusions: A subset of p53abn EC is morphologically low-grade EEC and exhibit genomic instability. Even for stage I disease, p53abn low-grade EEC are at substantial risk of disease recurrence. These findings highlight the clinical relevance of universal p53-testing, even in low-grade EEC, to identify women at increased risk of recurrence.

Prognostic Integrated Image-Based Immune and Molecular Profiling in Early-Stage Endometrial Cancer

Abstract Optimum risk stratification in early-stage endometrial cancer combines clinicopathologic factors and the molecular endometrial cancer classification defined by The Cancer Genome Atlas (TCGA). It is unclear whether analysis of intratumoral immune infiltrate improves this. We developed a machine-learning, image-based algorithm to quantify density of CD8+ and CD103+ immune cells in tumor epithelium and stroma in 695 stage I endometrioid endometrial cancers from the PORTEC-1 and -2 trials. The relationship between immune cell density and clinicopathologic/molecular factors was analyzed by hierarchical clustering and multiple regression. The prognostic value of immune infiltrate by cell type and location was analyzed by univariable and multivariable Cox regression, incorporating the molecular endometrial cancer classification. Tumor-infiltrating immune cell density varied substantially between cases, and more modestly by immune cell type and location. Clustering revealed three groups with high, intermediate, and low densities, with highly significant variation in the proportion of molecular endometrial cancer subgroups between them. Univariable analysis revealed intraepithelial CD8+ cell density as the strongest predictor of endometrial cancer recurrence; multivariable analysis confirmed this was independent of pathologic factors and molecular subgroup. Exploratory analysis suggested this association was not uniform across molecular subgroups, but greatest in tumors with mutant p53 and absent in DNA mismatch repair–deficient cancers. Thus, this work identified that quantification of intraepithelial CD8+ cells improved upon the prognostic utility of the molecular endometrial cancer classification in early-stage endometrial cancer.

Margin and robustness settings for a library-of-plans IMPT strategy for locally advanced cervical cancer

Abstract Objective. This study aims to determine a margin and robustness setting for treating locally advanced cervical cancer (LACC) with a library-of-plans (LoP) based online-adaptive intensity-modulated proton therapy (IMPT). Approach. We analyzed 13 LACC patients with delineated planning and weekly repeat CT scans (reCTs). For each patient, 120 IMPT treatments of 25 fractions were simulated with a LoPs approach. Six different robustness settings (2–7 mm set-up robustness (SR) plus 3% range robustness (RR)) were used to create those 120 IMPT plans. Each fraction was simulated with a weekly reCT, combined with the sampling of inter- and intrafraction treatment uncertainties. The fraction doses were accumulated to obtain a treatment dose to the target volumes, distinguishing between the low-risk clinical target volume (CTV-T-LR) and the elective CTV (CTV-E). If one of the two targets obtained an adequate coverage for more than 90% of the treatments, different anisotropic margins were sampled on top of the robustness setting to the other target to obtain the Pareto-optimal margin in terms of adequate coverage versus increase in target volume. Main results. The percentage of treatments that reach the dose criterion V 42.75Gy > 95% for the CTV-T-LR was 22.3%, 28.5%, 51.2%, 73.1%, 85.3%, and 90.0% for 2, 3, 4, 5, 6, and 7 mm SR plus 3% RR and for the CTV-E, this percentage was 60.4%, 73.8%, 86.5%, 92.3%, 96.9%, and 98.5%. The Pareto-optimal margin combined with a 5 mm/3% robustness setting for the CTV-T-LR with an adequate coverage for >90% of the treatments was given by {0, 1, 0, 3, 3, 0} mm in the left, right, anterior, posterior, cranial, caudal direction. Significance. Our study evaluated combinations of robustness and anisotropic margin settings for IMPT for LACC. With 5 mm SR and 3% RR for CTV-E and CTV-T-LR plus a margin to the CTV-T-LR of {0, 1, 0, 3, 3, 0} mm in left, right, anterior, posterior, cranial, and caudal ensured an adequate coverage for >90% of the simulated IMPT treatments.

Automated planning of curved needle channels in 3D printed patient-tailored applicators for cervical cancer brachytherapy

Abstract Purpose. Patient-tailored intracavitary/interstitial (IC/IS) brachytherapy (BT) applicators may increase dose conformity in cervical cancer patients. Current configuration planning methods in these custom applicators rely on manual specification or a small set of (straight) needles. This work introduces and validates a two-stage approach for establishing channel configurations in the 3D printed patient-tailored ARCHITECT applicator. Methods. For each patient, the patient-tailored applicator shape was based on the first BT application with a commercial applicator and integrated connectors to a commercial (Geneva) intrauterine tube and two lunar ring channels. First, a large candidate set was generated of channels that steer the needle to desired poses in the target region and are contained in the applicator. The channels’ centrelines were represented by Bézier curves. Channels running between straight target segments and entry points were optimised and refined to ensure (dynamic) feasibility. Second, channel configurations were selected using geometric coverage optimisation. This workflow was applied to establish patient-tailored geometries for twenty-two patients previously treated using the Venezia applicator. Treatment plans were automatically generated using the in-house developed algorithm BiCycle. Plans for the clinically used configuration, T P clin , and patient-tailored configuration, T P arch , were compared. Results. Channel configurations could be generated in clinically feasible time (median: 2651 s, range 1826–3812 s). All T P arch and T P clin plans were acceptable, but planning aims were more frequently attained with patient-tailored configurations (115/132 versus 100/132 instances). Median CTVIR D 98 and bladder D 2 c m 3 doses significantly improved ( p < 0.001 and p < 0.01 respectively) in T P arch plans in comparison with T P clin plans, and in approximately half of the patients dosimetric indices improved. Conclusion. Automated patient-tailored BT channel configuration planning for 3D printed applicators is clinically feasible. A treatment planning study showed that all plans met planning limits for the patient-tailored configurations, and in selected cases improved the plan quality in comparison with commercial applicator configurations.

Acute and long-term toxicity in patients undergoing induction chemotherapy followed by thermoradiotherapy for advanced cervical cancer

To determine rates of vascular toxicity, acute kidney injury (AKI), chronic kidney disease (CKD) and survival in high-risk cervical cancer patients treated with platinum-based induction chemotherapy followed by thermoradiotherapy. Between January 1999 and April 2017, patients with large primary tumors (>6cm) and/or para-aortic lymph node (LN) metastases >1 cm and/or para-iliac LN >2 cm were included. Patient and tumor characteristics, Common Toxicity Criteria v4.03 scores, laboratory tests and treatment data were retrieved from patient records. CT scans were reviewed for the presence of thrombo-embolic events (TEE). The study protocol was approved by the Medical Ethics Review Committee of Erasmus MC, Rotterdam (MEC2017-133). The 105 included patients had a mean age of 47.9 years (range 22-79) and a median follow-up time of 43 months (IQR 14-72). Median tumor size was 6.0 cm (range 2.6-11.5), 30% had a clinical FIGO stage ≥ IIIB and 42% had enlarged para-aortic LN. Cisplatin-based therapy was started in 86 patients (82%), of whom 30 (35%) switched to carboplatin and 47% of patients completed six cycles of platinum-based chemotherapy. All patients received external beam radiotherapy as planned, 98 patients (93%) underwent brachytherapy as planned or received an external boost, and 95 patients (90%) completed all five planned hyperthermia treatments. During cisplatin chemotherapy, 34 patients experienced AKI (39%). At last follow-up, 35% of patients had chronic renal toxicity (GFR 59 - 15/min/1.73 m Achieving a five-year overall survival of 58%, platinum-based induction chemotherapy followed by thermoradiotherapy is an effective treatment for advanced-stage high-risk cervical cancer. However, treatment is accompanied by an unacceptably high prevalence of chemotherapy-associated TEE and acute kidney injury, as well as chronic kidney disease. Future studies should investigate the role of carboplatin in reducing toxicity and the effect of thromboprophylaxis in high-risk patients.

Afterloader integrated EMT enables improved dwell position model definition and quality assurance in Venezia gynaecological brachytherapy applicators

Abstract Objective. In brachytherapy for gynecological cancers using intracavitary applicators, implant reconstruction is commonly performed using applicator libraries. These libraries contain applicator geometry models as well as dwell position (DP) models defined in respect to the applicator geometry. In this study, we investigate whether an afterloader integrated electromagnetic tracking (EMT) system can be utilized for DP model definition and quality assurance in such applicators. Approach. DPs in four sets of two configurations of the Elekta Venezia Advanced Gynaecological Applicator (22 mm ovoids/40 mm intrauterine (IU) and 26 mm ovoids/70 mm IU) were measured using an afterloader integrated EMT system. Measurements were evaluated for reproducibility and compared against manufacturer-specified (MS) DPs and a computed tomography (CT)-corrected DP model. Main Results. Excellent EMT measurement reproducibility was observed, with values of ⩽0.2 mm for both configurations. The overall reproducibility, including applicator geometry reproducibility, was ⩽0.4 mm for both configurations. Significant discrepancies from the manufacturer’s DP model were observed, with a mean ± sd deviation of 1.13 ± 0.66 mm (22/40) and 1.37 ± 0.63 (26/70), particularly in the IU channel, where MS DPs were not experimentally defined. Discrepancies were reduced to 0.89 ± 0.41 mm (22/40) and 0.81 ± 0.33 mm (26/70) when the CT-corrected DP model was used as baseline, highlighting the need for experimentally defined DP models. The overall uncertainty of single measurements was below the clinically acceptable 2 mm limit. Significance. This study confirms that afterloader integrated EMT can accurately reconstruct source paths in gynecological brachytherapy applicators and supports its incorporation into clinical workflows for improved quality assurance and treatment precision. The importance of EMT for quality assurance was highlighted by measured deviations from manufacturer’s DP model in a clinical relevant part of the IU channel.

15Works
7Papers
47Collaborators
1Trials