The prognostic significance of a negative PSMA-PET scan prior to salvage radiotherapy following radical prostatectomy.

AIM: The optimal management for early recurrent prostate cancer following radical prostatectomy (RP) in patients with negative prostate-specific membrane antigen positron-emission tomography (PSMA-PET) scan is an ongoing subject of debate. The aim of this study was to evaluate the outcome of salvage radiotherapy (SRT) in patients with biochemical recurrence with negative PSMA PET finding. METHODS: This retrospective, multicenter (11 centers, 5 countries) analysis included patients who underwent SRT following biochemical recurrence (BR) of PC after RP without evidence of disease on PSMA-PET staging. Biochemical recurrence-free survival (bRFS), metastatic-free survival (MFS) and overall survival (OS) were assessed using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predefined predictors of survival outcomes. RESULTS: Three hundred patients were included, 253 (84.3%) received SRT to the prostate bed only, 46 (15.3%) additional elective pelvic nodal irradiation, respectively. Only 41 patients (13.7%) received concomitant androgen deprivation therapy (ADT). Median follow-up after SRT was 33 months (IQR: 20-46 months). Three-year bRFS, MFS, and OS following SRT were 73.9%, 87.8%, and 99.1%, respectively. Three-year bRFS was 77.5% and 48.3% for patients with PSA levels before PSMA-PET ≤ 0.5 ng/ml and > 0.5 ng/ml, respectively. Using univariate analysis, the International Society of Urological Pathology (ISUP) grade > 2 (p = 0.006), metastatic pelvic lymph nodes at surgery (p = 0.032), seminal vesicle involvement (p < 0.001), pre-SRT PSA level of > 0.5 ng/ml (p = 0.004), and lack of concomitant ADT (p = 0.023) were significantly associated with worse bRFS. On multivariate Cox proportional hazards, seminal vesicle infiltration (p = 0.007), ISUP score >2 (p = 0.048), and pre SRT PSA level > 0.5 ng/ml (p = 0.013) remained significantly associated with worse bRFS. CONCLUSION: Favorable bRFS after SRT in patients with BR and negative PSMA-PET following RP was achieved. These data support the usage of early SRT for patients with negative PSMA-PET findings.

Whole pelvis vs. hemi pelvis elective nodal radiotherapy in patients with PSMA-positive nodal recurrence after radical prostatectomy - a retrospective multi-institutional propensity score analysis.

PURPOSE: Despite growing evidence for bilateral pelvic radiotherapy (whole pelvis RT, WPRT) there is almost no data on unilateral RT (hemi pelvis RT, HPRT) in patients with nodal recurrent prostate cancer after prostatectomy. Nevertheless, in clinical practice HPRT is sometimes used with the intention to reduce side effects compared to WPRT. Prostate-specific membrane antigen positron emission tomography / computed tomography (PSMA-PET/CT) is currently the best imaging modality in this clinical situation. This analysis compares PSMA-PET/CT based WPRT and HPRT. METHODS: A propensity score matching was performed in a multi-institutional retrospective dataset of 273 patients treated with pelvic RT due to nodal recurrence (214 WPRT, 59 HPRT). In total, 102 patients (51 in each group) were included in the final analysis. Biochemical recurrence-free survival (BRFS) defined as prostate specific antigen (PSA) < post-RT nadir + 0.2ng/ml, metastasis-free survival (MFS) and nodal recurrence-free survival (NRFS) were calculated using the Kaplan-Meier method and compared using the log rank test. RESULTS: Median follow-up was 29 months. After propensity matching, both groups were mostly well balanced. However, in the WPRT group there were still significantly more patients with additional local recurrences and biochemical persistence after prostatectomy. There were no significant differences between both groups in BRFS (p = .97), MFS (p = .43) and NRFS (p = .43). After two years, BRFS, MFS and NRFS were 61%, 86% and 88% in the WPRT group and 57%, 90% and 82% in the HPRT group, respectively. Application of a boost to lymph node metastases, a higher RT dose to the lymphatic pathways (> 50 Gy EQD2α/ß=1.5 Gy) and concomitant androgen deprivation therapy (ADT) were significantly associated with longer BRFS in uni- and multivariate analysis. CONCLUSIONS: Overall, this analysis presents the outcome of HPRT in nodal recurrent prostate cancer patients and shows that it can result in a similar oncologic outcome compared to WPRT. Nevertheless, patients in the WPRT may have been at a higher risk for progression due to some persistent imbalances between the groups. Therefore, further research should prospectively evaluate which subgroups of patients are suitable for HPRT and if HPRT leads to a clinically significant reduction in toxicity.

Intracavitary brachytherapy with additional Heyman capsules in the treatment of cervical cancer.

PURPOSE: Brachytherapy is a mandatory component of primary radiochemotherapy in cervical cancer. The dose can be applied with a traditional intracavitary approach (IC alone) or with multiple catheter brachytherapy to optimize dose distribution in an individual concept. We therefore evaluated whether the utilization of a tandem-ring applicator plus additional intracavitary applicators (add IC) provides an advantage over the traditional IC alone approach, as this method is less time consuming and less invasive compared to a combined intracavitary/interstitial brachytherapy. METHODS: Twenty three procedures of intracavitary brachytherapy for cervical cancer with additional intracavitary applicators performed in seven patients treated between 2016 and 2018 in our institution were included in this study. Plans were optimized for D90 HR-CTV with and without the utilization of the additional applicators and compared by statistical analysis. RESULTS: D90 for HR-CTV was 5.71 Gy (±1.17 Gy) for fractions optimized with add IC approach and 5.29 Gy (±1.24 Gy) for fractions without additional applicators (p < 0.01). This translates to a calculated mean EQD2 HR-CTV D90 of 80.72 Gy (±8.34 Gy) compared to 77.84 Gy (±8.49 Gy) after external beam therapy and four fractions of brachytherapy for add IC and IC alone, respectively (p < 0.01). The predictive value of improved coverage of HR-CTV in the first fraction was high. CONCLUSION: In a subgroup of cases, the addition of intracavitary Heyman capsules can be an alternative to interstitial brachytherapy to improve the plan quality compared to standard IC alone brachytherapy. The benefit from the addition of applicators in the first fraction is predictive for the following fractions.

First experiences with PET-MRI/CT in radiotherapy planning for cervical cancer.

PURPOSE: PET-CT has recently been included in the NCCN staging recommendations for cervical cancer stages II-IV and is already routinely applied to radiotherapy planning for other malignancies, as it is expected to provide higher accuracy for the detection of areas with tumor cell spread. In this study, we report on our first experiences of PET-based radiotherapy planning for cervical cancer. METHODS: 19 patients with cervical cancer that underwent pre-therapeutic PET imaging treated at our institution between January 2016 and April 2019 were included in the study. Information on the primary tumor, lymph node involvement, metastatic spread and changes in the radiotherapy procedure based on the PET findings are described. RESULTS: A previously unknown primary tumor extension that was detected by PET imaging in one patient. In patients who underwent a PET before the systematic pelvic and paraaortic lymphonodectomy (n = 2), PET was false negative for pelvic lymph node metastases in 50%. In patients who underwent a PET after the systematic LNE (n = 13), additional lymph node metastases were detected in seven patients (53.80%). Distant metastases were suspected in three patients (15.7%) based on PET imaging. The suspicion was confirmed in one patient (peritoneal spread) and excluded in two patients (supra-diaphragmatic lymph nodes). In 13 patients (68.4%), RT procedures were altered due to findings in PET imaging. CONCLUSION: PET-based radiochemotherapy planning may improve control rates by identifying areas of tumor cell spread eligible for dose escalation. False positivity, however, should be excluded in patients with findings that lead to major modifications of the therapeutic strategy.

Factors influencing treatment decision and guideline conformity in high-grade endometrial cancer patients: a population-based study.

PURPOSE: Treatment according to guidelines has been demonstrated to improve survival in a number of different cancer entities. Deviations from guidelines depend on several factors, including the patient's preferences, age and comorbidities. The aim of this study was to assess the adherence to guideline recommendations concerning surgical and adjuvant treatment in endometrial cancer. Furthermore, we sought to evaluate the reasons for non-adherence to guidelines by further examining the influence of comorbidities and age. METHODS: The influence of age, comorbidities, tumor stage and histological subtype on guideline adherence was evaluated by multivariable logistic regression in a cohort of 353 high-grade endometrial cancer patients. High-grade endometrial cancer was defined as carcinosarcoma, Type II (serous, clear cell, mixed cell carcinoma) and Type I G3 histology. RESULTS: Extensive surgical procedures, particularly systematic LNE, were less frequently applied in patients with comorbidities (p = 0.015) or higher age (p < 0.01). Guideline adherence was not affected by comorbidities (p = 0.563), but was significantly reduced with higher age (p < 0.01). In a multivariable model, higher age (p < 0.01), obesity (p = 0.011), higher FIGO Stage (p < 0.01) and histologic subtype (p < 0.01) significantly decreased OS. Surgery (p < 0.001), chemotherapy (p < 0.01) and systematic LNE (p = 0.011) were associated with higher OS. CONCLUSION: Age seems to be the strongest independent factor leading to guideline deviation. Comorbidities were associated with less aggressive treatment, but not with deviations from guidelines.

Comparison of survival outcomes and effects of therapy between subtypes of high-grade endometrial cancer - a population-based study.

BACKGROUND: Similarities in outcome between grade 3 endometrioid cancer and non-endometrioid histologies have been reported by a number of studies. Other reports, however, stated a significantly better prognosis for G3 endometrioid compared to type II histology. In this population-based study, we compared the outcome and treatment approaches of high-grade endometrial cancer patients with FIGO stages I-III depending on their histology. MATERIAL AND METHODS: 284 high-grade endometrial cancer patients diagnosed between 1998 and 2015 were retrospectively analyzed. Overall survival (OS), recurrence-free survival (RFS), and recurrence rates were compared depending on histology. RESULTS: Type I G3 patients had a statistically significant OS advantage over women suffering from type II carcinoma (HR 1.527, 95%-CI 1.024-2.276; p = 0.038) and carcinosarcoma (HR 2.106, 95%-CI 1.270-3.493; p = 0.004) in univariable and multivariable Cox-regression analysis. RFS in Type I G3 was significantly superior compared to patients with carcinosarcoma (HR 1.719, 95%-CI 1.018-2.901; p = 0.043) and not significantly superior to type II patients (HR 1.368, 95%-CI 0.920-2.036; p = 0.122). Cumulative recurrence rates were significantly higher in carcinosarcoma compared to type I G3 (HR 2.217, 95%-CI 1.096-4.485; p = 0.027) in univariable analysis, but not after risk adjustment (HR of 1.472, 95%-CI 0.654-3.311; p = 0.350). CONCLUSION: The prognosis of patients with type I G3 endometrial cancer patients seems to be significantly superior to patients with type II cancer and particularly carcinosarcoma. Systematic LND seemed to be beneficial in all of the three subtypes. The benefit of adjuvant treatment methods may differ between histologies.

Is there a benefit for adjuvant radio(chemo)therapy in early cervical cancer? Results from a population-based study.

PURPOSE: Due to insufficient and conflicting prospective evidence, the recommendations on when to apply adjuvant radiochemotherapy in early-stage cervical cancer vary between international guidelines. In this population-based study, we evaluated the outcome of patients with early-stage cervical cancer based on risk factors and the adjuvant therapy they received. METHODS: The effect of primary therapy (surgery and radiochemotherapy RCT, surgery and radiotherapy RT, and surgery alone) on overall survival (OS) and recurrence-free survival (RFS) was evaluated in the complete cohort of 442 patients and in subgroups according to risk profile and nodal status. RESULTS: In low-risk patients, there was no difference in OS (p = 0.276) depending on whether patients received adjuvant therapy or not. Concerning RFS, patients with RT (including one patient with RCT) exhibited a significantly worse outcome compared to the group with surgery alone (p = 0.015). In intermediate-risk patients, the administration of adjuvant RT significantly benefited RFS when compared to surgery only in multivariate analysis (p = 0.031). Concerning OS, no significant influence for adjuvant treatment could be seen (p = 0.354). Though trends towards better OS and RFS could be observed in patients of the high-risk group-both in RCT and RT groups compared to surgery alone-the effects did not prove to be significant. CONCLUSION: Our study reaffirms the evidence against the use of adjuvant radio(chemo)therapy in low-risk early-stage cervical cancer. In intermediate-, and less pronounced in high-risk patients, however, it seems to be beneficial. The role of adjuvant radio(chemo)therapy in early cervical cancer should be further investigated in prospective randomized trials.

Value of indocyanine green pelvic lymph node mapping in the surgical approach of cervical cancer.

PURPOSE: Lymph node metastasis is a significant predictive factor for disease recurrence and survival in cervical cancer patients and relevant for therapeutic strategies. We evaluated the clinical value of indocyanine green (ICG) by measuring the sensitivity and negative predictive value of sentinel lymph node mapping compared with the gold standard of complete lymphadenectomy in detecting lymph node metastases for cervical cancer. METHODS: We utilized the near-infrared imaging agent ICG to detect tumor-infested lymph nodes in the pelvis analogue to a classical sentinel lymph node procedure by analyzing data from 20 patients who had undergone surgery for cervical cancer at our institution. A laparoscopic lymph node mapping procedure by means of ICG, followed by a complete pelvic lymphadenectomy with or without paraaortic lymphadenectomy was done in all patients. RESULTS: Histological examination identified seven patients with tumor-positive pelvic nodes, whereas mapping with ICG identified only five of these patients. Detection rate of positive nodes by ICG mapping and false negative rate was 71.4% and 28.6%, respectively; bilateral detection rate was 83.3%. One of the two false negative patients additionally suffered from deep infiltrating endometriosis. CONCLUSIONS: Our results indicate that ICG can identify the relevant pelvic nodes independent of tumor size, provided bilateral detection is achieved and additional, related diseases are excluded. TRIAL REGISTRATION: This trial is registered within the German Clinical Trial Register (DRKS-ID: DRKS00014692).

Cavity volume changes after surgery of a brain metastasis-consequences for stereotactic radiation therapy.

PURPOSE: For a large or symptomatic brain metastasis, resection and adjuvant radiotherapy are recommended. Hypofractionated stereotactic radiotherapy (HFSRT) is increasingly applied in patients with a limited number of lesions. Exact target volume definition is critical given the small safety margins. Whilst technical advances have minimized inaccuracy due to patient positioning and radiation targeting, little is known about changes in target volume. This study sought to evaluate potential changes in the resection cavity of a brain metastasis. METHODS: In all, 57 patients treated with HFSRT after surgical resection of one brain metastasis between 2008 and 2015 in our institution were included in this study. Gross tumor volume (GTV) of the initial metastasis and the volume of the resection cavity in the post-operative, planning, and follow-up MRIs were measured and compared. RESULTS: The mean cavity size decreased after surgery with the greatest change of -23.4% (±41.5%) occurring between post-operative MRI and planning MRI (p < 0.01). During this time period, the cavity volume decreased, remained stable, and increased in 79.1, 3.5, and 17.4%, respectively. A further decrease of -20.7% (±58.1%) was perceived between planning MRI and first follow-up (p < 0.01). No significant difference in pattern of change could be observed depending on the volume of initial GTV, size of the post-operative resection cavity, initial or post-resection FLAIR (fluid-attenuated inversion recovery) hyper-intensity, postsurgical ischemia, or primary tumor. The resection cavities of patients with post-operative ischemia were significantly larger than resection cavities of patients without ischemia. CONCLUSION: The resection cavity seems to be very dynamic after surgery. Hence, it remains necessary to use very recent scans for treatment planning.

Stereotactic irradiation of the resection cavity after surgical resection of brain metastases - when is the right timing?

Purpose: This study aimed to evaluate whether an early beginning of the adjuvant stereotactic radiotherapy after macroscopic complete resection of 1-3 brain metastases is essential or whether longer intervals between surgery and radiotherapy are feasible.Material and methods: Sixty-six patients with 69 resection cavities treated with HFSRT after macroscopic complete resection of 1-3 brain metastases between 2009 and 2016 in our institution were included in this study. Overall survival, local recurrence and locoregional recurrence were evaluated depending on the time interval from surgery to the start of radiation therapy.Results: Patients that started radiotherapy within 21 days from surgery had a significantly decreased OS compared to patients treated after a longer interval from surgery (p < .01). There was no significant difference between patients treated ≥ 34 and 22-33 days from surgery (p = .210). In the univariate analysis, local control was superior for patients starting treatment 22-33 days from surgery compared to a later start (p = .049). This effect did not prevail in a multivariate model. There was no significant difference between patients treated within 21 days and patients treated more than 33 days after surgery (p = .203). Locoregional control was not influenced by RT timing (p = .508).Conclusion: A short delay in the start of radiotherapy does not seem to negatively impact the outcome in patients with resected brain metastases. We even observed an unexpected reduction in OS in patients treated within 21 days from surgery. Further studies are needed to define the optimal timing of postoperative radiotherapy to the resection cavity.

Quality of life and oncological outcome in endometrial cancer patients after vaginal brachytherapy: comparison of two dosing schemes.

PURPOSE: Vaginal brachytherapy reduces the risk of local recurrence and was shown to be equieffective in preventing vaginal vault recurrence, but less toxic compared to external-beam radiotherapy in a subset of high intermediate-risk endometrial cancer patients and is administered as single adjuvant treatment in those patients. Different radiotherapeutic approaches with various dosing schemes exist toward brachytherapy. The aim of this study was to compare the outcome and long-term quality of life after brachytherapy with two different high-dose-rate dosing schemes. METHODS: Retrospective analysis was conducted of the recurrence and survival rates of 104 patients with endometrial cancer FIGO stage I-II that underwent adjuvant brachytherapy with three times 5 Gy or four times 5 Gy to the upper two-thirds of the vaginal vault in two different institutions between January 2010 and December 2013. Quality of life was assessed by EORTC QLQ-30 questionnaire and EN 24 module. RESULTS: The vaginal vault recurrence rates were 4.9% and 5.0% for patients treated with 3 × 5 Gy and 4 × 5 Gy, respectively (p = 0.98). We did not observe a difference in pelvic recurrence (p = 0.96), overall survival (p = 0.33) or quality of life between the different radiotherapy regimens. Metastatic recurrence and the use of chemotherapy contribute to impairment on quality of life. Younger patients (< 70 years) reported worse emotional functioning (p = 0.02) and higher symptom scales of diarrhea (p = 0.01) and financial problems (p = 0.03). Sexual activity was lower in patients younger than 70 years (p = 0.05). CONCLUSIONS: Further prospective studies are needed to evaluate the effect of dosing schemes on recurrence rates and quality of life. Younger patients (< 70 years) seem to experience greater reduction in quality of life due to endometrial cancer diagnosis.

Does post-operative radiochemotherapy improve survival in high-grade endometrial cancer patients? Results of a population-based cohort analysis of a cancer registry.

PURPOSE: Adjuvant treatment of high-grade endometrial cancer varies greatly due to the lack of definitive results from controlled randomized trials on the subject. In a retrospective study, we sought to investigate the influence of post-operative radio-, chemo, and radiochemotherapy on survival time and recurrence rates among high-grade endometrial cancer patients. METHODS: 284 high-grade endometrial cancer patients (FIGOI-III, or unknown classification) diagnosed between 1998 and 2015 were retrospectively analyzed. All patients underwent surgery. Overall survival (OS), recurrence-free survival (RFS), and recurrence rates were compared for post-operative treatment modalities of radiotherapy alone (RT), chemotherapy alone (CTX), radiochemotherapy (RCT), and observation (OBS). RESULTS: Post-operative RCT and RT resulted in a significantly improved 5-year OS of 94.1% (HR 0.104, CI 0.013-0.809) and 62.1% (HR 0.615, CI 0.390-0.969), respectively, compared to 43.6% for OBS. CTX did not significantly improve OS leading to a 5-year OS of 56.5% (HR 0.783, CI 0.224-2.740). 5-year recurrence rate was lowest for patients treated with RCT (5.3%). 5-year RFS was 94.1% for the RCT group and proved to be significantly superior to 58.8% for RT (HR 9.034, CI 1.184-68.948), 56% for CTX (HR 12.738, CI 1.337-121.346), and 37.4% for OBS (HR 16.407, CI 2.127-126.575), respectively. In comparison with OBS, RT alone resulted in a significant improvement in RFS (HR 0.551, CI 0.354-0.856). CONCLUSIONS: Our retrospective population-based study indicates a survival benefit from treating high-grade endometrial cancer with post-operative RCT. Randomized controlled trials are needed to minimize potential confounding parameters and further clarify the subject.

Undetectable PSA predicts outcome after salvage radiotherapy for biochemical recurrence following radical prostatectomy.

BACKGROUND AND PURPOSE: Salvage radiotherapy (SRT) is a curative treatment option in patients with biochemical recurrence after radical prostatectomy (RP). Undetectable prostate-specific antigen (PSA) < 0.1 ng/mL following SRT predicts biochemical progression-free survival (BPFS). The aim of this large retrospective study was to evaluate whether this effect persists in an extended follow-up of >5 years. MATERIALS AND METHODS: A total of 678 patients treated with SRT for biochemical recurrence after RP were included. Exclusion criteria were lymph node or distant metastases, pre-SRT PSA > 3 ng/mL, and receipt of androgen deprivation therapy (ADT) between RP and SRT. All patients received a median dose of 70.2 (range 59.4-72.0) Gy to the prostatic fossa. The log-rank test (Kaplan-Meier) and Cox regression analysis were used to evaluate the impact of disease- and treatment-related parameters on BPFS, metastasis-free survival (MFS), and overall survival (OS). RESULTS: Median follow-up after SRT was 5.6 (range 0.1-14.5) years. The 5-year BPFS was 77.8 % in patients with a PSA nadir < 0.1 ng/mL (undetectable) and 16.3 % in the remaining cohort (p < 0.001). Five-year MFS was 95.3 % with undetectable PSA versus 84.0 % with detectable PSA (p < 0.001), and 5-year OS values were 97.5 % and 92.7 % with undetectable versus detectable PSA, respectively (p = 0.04). In multivariate analysis, undetectable PSA was the strongest predictor of BPFS (HR = 0.122; 95 %CI: 0.080-0.187; p < 0.001) and MFS (HR = 0.262; 95 %CI: 0.136-0.594; p < 0.001), but was not significant for OS (HR = 0.615; 95 %CI: 0.298-1.269; p = 0.189). CONCLUSION: PSA < 0.1 ng/mL following SRT without ADT is a significant predictor of BPFS and MFS. The results suggest that it might be feasible to withhold ADT in selected patients if they have undetectable PSA after SRT. Prospective studies are warranted to confirm these findings.

European association of urology risk stratification predicts outcome in patients receiving PSMA-PET-planned salvage radiotherapy for biochemical recurrence following radical prostatectomy.

PURPOSE: The European Association of Urology (EAU) proposed a risk stratification (high vs. low risk) for patients with biochemical recurrence (BR) following radical prostatectomy (RP). Here we investigated whether this stratification accurately predicts outcome, particularly in patients staged with PSMA-PET. METHODS: For this study, we used a retrospective database including 1222 PSMA-PET-staged prostate cancer patients who were treated with salvage radiotherapy (SRT) for BR, at 11 centers in 5 countries. Patients with lymph node metastases (pN1 or cN1) or unclear EAU risk group were excluded. The remaining cohort comprised 526 patients, including 132 low-risk and 394 high-risk patients. RESULTS: The median follow-up time after SRT was 31.0 months. The 3-year biochemical progression-free survival (BPFS) was 85.7 % in EAU low-risk versus 69.4 % in high-risk patients (p = 0.002). The 3-year metastasis-free survival (MFS) was 94.4 % in low-risk versus 87.6 % in high-risk patients (p = 0.005). The 3-year overall survival (OS) was 99.0 % in low-risk versus 99.6 % in high-risk patients (p = 0.925). In multivariate analysis, EAU risk group remained a statistically significant predictor of BPFS (p = 0.003, HR 2.022, 95 % CI 1.262-3.239) and MFS (p = 0.013, HR 2.986, 95 % CI 1.262-7.058). CONCLUSION: Our data support the EAU risk group definition. EAU risk grouping for BCR reliably predicted outcome in patients staged lymph node-negative after RP and with PSMA-PET before SRT. To our knowledge, this is the first study validating the EAU risk grouping in patients treated with PSMA-PET-planned SRT.

A Machine Learning Approach for Predicting Biochemical Outcome After PSMA-PET-Guided Salvage Radiotherapy in Recurrent Prostate Cancer After Radical Prostatectomy: Retrospective Study.

BACKGROUND: Salvage radiation therapy (sRT) is often the sole curative option in patients with biochemical recurrence after radical prostatectomy. After sRT, we developed and validated a nomogram to predict freedom from biochemical failure. OBJECTIVE: This study aims to evaluate prostate-specific membrane antigen-positron emission tomography (PSMA-PET)-based sRT efficacy for postprostatectomy prostate-specific antigen (PSA) persistence or recurrence. Objectives include developing a random survival forest (RSF) model for predicting biochemical failure, comparing it with a Cox model, and assessing predictive accuracy over time. Multinational cohort data will validate the model's performance, aiming to improve clinical management of recurrent prostate cancer. METHODS: This multicenter retrospective study collected data from 13 medical facilities across 5 countries: Germany, Cyprus, Australia, Italy, and Switzerland. A total of 1029 patients who underwent sRT following PSMA-PET-based assessment for PSA persistence or recurrence were included. Patients were treated between July 2013 and June 2020, with clinical decisions guided by PSMA-PET results and contemporary standards. The primary end point was freedom from biochemical failure, defined as 2 consecutive PSA rises >0.2 ng/mL after treatment. Data were divided into training (708 patients), testing (271 patients), and external validation (50 patients) sets for machine learning algorithm development and validation. RSF models were used, with 1000 trees per model, optimizing predictive performance using the Harrell concordance index and Brier score. Statistical analysis used R Statistical Software (R Foundation for Statistical Computing), and ethical approval was obtained from participating institutions. RESULTS: Baseline characteristics of 1029 patients undergoing sRT PSMA-PET-based assessment were analyzed. The median age at sRT was 70 (IQR 64-74) years. PSMA-PET scans revealed local recurrences in 43.9% (430/979) and nodal recurrences in 27.2% (266/979) of patients. Treatment included dose-escalated sRT to pelvic lymphatics in 35.6% (349/979) of cases. The external outlier validation set showed distinct features, including higher rates of positive lymph nodes (47/50, 94% vs 266/979, 27.2% in the learning cohort) and lower delivered sRT doses (<66 Gy in 57/979, 5.8% vs 46/50, 92% of patients; P<.001). The RSF model, validated internally and externally, demonstrated robust predictive performance (Harrell C-index range: 0.54-0.91) across training and validation datasets, outperforming a previously published nomogram. CONCLUSIONS: The developed RSF model demonstrates enhanced predictive accuracy, potentially improving patient outcomes and assisting clinicians in making treatment decisions.

Guideline concordant therapy improves survival in high-grade endometrial cancer patients.

PURPOSE: Data from randomized controlled trials in high-grade endometrial cancer are scarce due to its low prevalence. Therefore, guideline recommendations in this cancer subtype rely on relatively few randomized trials and data from retrospective studies. The aim of this study was to evaluate the benefits from guideline-concordant therapy in high-grade endometrial cancer in a real-world patient group. METHODS: The effect of treatment according to German S3 guidelines and the former S2k guideline on overall survival (OS) and recurrence-free survival (RFS) was evaluated in a cohort of 293 high-grade endometrial cancer patients. RESULTS: Treatment concordant with the S3 guideline significantly improved OS (HR 0.623, CI 0.420-0.923, p = 0.018) and RFS (HR 0.578, CI 0.387-0.863, p = 0.007). Treatment concordant with the S2k guideline did not result in a significantly higher OS (HR 0.783, CI 0.465-1.316, p = 0.335) or RFS (HR 0.741, CI 0.347-1.740, p = 0.242). CONCLUSION: Therapy according to the German S3 guideline improved OS and RFS in univariate as well as multivariate analysis in this cohort of high-grade endometrial cancer patients.

Development and Validation of a Multi-institutional Nomogram of Outcomes for PSMA-PET-Based Salvage Radiotherapy for Recurrent Prostate Cancer.

Importance: Prostate-specific antigen membrane positron-emission tomography (PSMA-PET) is increasingly used to guide salvage radiotherapy (sRT) after radical prostatectomy for patients with recurrent or persistent prostate cancer. Objective: To develop and validate a nomogram for prediction of freedom from biochemical failure (FFBF) after PSMA-PET-based sRT. Design, Setting, and Participants: This retrospective cohort study included 1029 patients with prostate cancer treated between July 1, 2013, and June 30, 2020, at 11 centers from 5 countries. The initial database consisted of 1221 patients. All patients had a PSMA-PET scan prior to sRT. Data were analyzed in November 2022. Exposures: Patients with a detectable post-radical prostatectomy prostate-specific antigen (PSA) level treated with sRT to the prostatic fossa with or without additional sRT to pelvic lymphatics or concurrent androgen deprivation therapy (ADT) were eligible. Main Outcomes and Measures: The FFBF rate was estimated, and a predictive nomogram was generated and validated. Biochemical relapse was defined as a PSA nadir of 0.2 ng/mL after sRT. Results: In the nomogram creation and validation process, 1029 patients (median age at sRT, 70 years [IQR, 64-74 years]) were included and further divided into a training set (n = 708), internal validation set (n = 271), and external outlier validation set (n = 50). The median follow-up was 32 months (IQR, 21-45 months). Based on the PSMA-PET scan prior to sRT, 437 patients (42.5%) had local recurrences and 313 patients (30.4%) had nodal recurrences. Pelvic lymphatics were electively irradiated for 395 patients (38.4%). All patients received sRT to the prostatic fossa: 103 (10.0%) received a dose of less than 66 Gy, 551 (53.5%) received a dose of 66 to 70 Gy, and 375 (36.5%) received a dose of more than 70 Gy. Androgen deprivation therapy was given to 325 (31.6%) patients. On multivariable Cox proportional hazards regression analysis, pre-sRT PSA level (hazard ratio [HR], 1.80 [95% CI, 1.41-2.31]), International Society of Urological Pathology grade in surgery specimen (grade 5 vs 1+2: HR, 2.39 [95% CI, 1.63-3.50], pT stage (pT3b+pT4 vs pT2: HR, 1.91 [95% CI, 1.39-2.67]), surgical margins (R0 vs R1+R2+Rx: HR, 0.60 [95% CI, 0.48-0.78]), ADT use (HR, 0.49 [95% CI, 0.37-0.65]), sRT dose (>70 vs ≤66 Gy: HR, 0.44 [95% CI, 0.29-0.67]), and nodal recurrence detected on PSMA-PET scans (HR, 1.42 [95% CI, 1.09-1.85]) were associated with FFBF. The mean (SD) nomogram concordance index for FFBF was 0.72 (0.06) for the internal validation cohort and 0.67 (0.11) in the external outlier validation cohort. Conclusions and Relevance: This cohort study of patients with prostate cancer presents an internally and externally validated nomogram that estimated individual patient outcomes after PSMA-PET-guided sRT.

Salvage radiotherapy is effective in patients with PSMA-PET-negative biochemical recurrence- results of a retrospective study.

BACKGROUND/PURPOSE: The present study aimed to assess whether SRT to the prostatic fossa should be initiated in a timely manner after detecting biochemical recurrence (BR) in patients with prostate cancer, when no correlate was identified with prostate-specific membrane antigen positron emission tomography (PSMA-PET). MATERIALS AND METHODS: This retrospective, multicenter analysis included 1222 patients referred for PSMA-PET after a radical prostatectomy due to BR. Exclusion criteria were: pathological lymph node metastases, prostate-specific antigen (PSA) persistence, distant or lymph node metastases, nodal irradiation, and androgen deprivation therapy (ADT). This led to a cohort of 341 patients. Biochemical progression-free survival (BPFS) was the primary study endpoint. RESULTS: The median follow-up was 28.0 months. The 3-year BPFS was 71.6% in PET-negative cases and 80.8% in locally PET-positive cases. This difference was significant in univariate (p = 0.019), but not multivariate analyses (p = 0.366, HR: 1.46, 95%CI: 0.64-3.32). The 3-year BPFS in PET-negative cases was significantly influenced by age (p = 0.005), initial pT3/4 (p < 0.001), pathology scores (ISUP) ≥ 3 (p = 0.026), and doses to fossa > 70 Gy (p = 0.027) in univariate analyses. In multivariate analyses, only age (HR: 1.096, 95%CI: 1.023-1.175, p = 0.009) and PSA-doubling time (HR: 0.339, 95%CI: 0.139-0.826, p = 0.017) remained significant. CONCLUSION: To our best knowledge, this study provided the largest SRT analysis in patients without ADT that were lymph node-negative on PSMA-PET. A multivariate analysis showed no significant difference in BPFS between locally PET-positive and PET-negative cases. These results supported the current EAU recommendation to initiate SRT in a timely manner after detecting BR in PET negative patients.