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.

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.

Can PSMA PET/CT help in dose-tailoring in post-prostatectomy radiotherapy?

There are few randomized trials to evaluate the use of PSMA-PET in the planning of post-prostatectomy radiotherapy. There are two unresolved questions 1) should we increase the dose to lesions visible on PSMA-PET 2) can we reduce dose in the case of a negative PSMA-PET. In this review, we summarize and discuss the available evidence in the literature. We found that in general, there seems to be an advantage for dose-increase, but ta large recent study from the pre-PSMA era didn't show an advantage for dose escalation. Retrospective studies have shown that conventional doses to PSMA-PET-positive lesions seem sufficient. On the other hand, in the case of a negative PSMA-PET, there is no evidence that dose-reduction is possible. In the future, the combination of PSMA-PET with genomic classifiers could help in better identify patients who might benefit from either dose- de-or -increase. We further need to identify intraindividual references to help identify lesions with higher aggressiveness.

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.

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.

Metastases-directed stereotactic body radiotherapy in combination with targeted therapy or immunotherapy: systematic review and consensus recommendations by the EORTC-ESTRO OligoCare consortium.

Stereotactic body radiotherapy (SBRT) for patients with metastatic cancer, especially when characterised by a low tumour burden (ie, oligometastatic disease), receiving targeted therapy or immunotherapy has become a frequently practised and guideline-supported treatment strategy. Despite the increasing use in routine clinical practice, there is little information on the safety of combining SBRT with modern targeted therapy or immunotherapy and a paucity of high-level evidence to guide clinical management. A systematic literature review was performed to identify the toxicity profiles of combined metastases-directed SBRT and targeted therapy or immunotherapy. These results served as the basis for an international Delphi consensus process among 28 interdisciplinary experts who are members of the European Society for Radiotherapy and Oncology (ESTRO) and European Organisation for Research and Treatment of Cancer (EORTC) OligoCare consortium. Consensus was sought about risk mitigation strategies of metastases-directed SBRT combined with targeted therapy or immunotherapy; a potential need for and length of interruption to targeted therapy or immunotherapy around SBRT delivery; and potential adaptations of radiation dose and fractionation. Results of this systematic review and consensus process compile the best available evidence for safe combination of metastases-directed SBRT and targeted therapy or immunotherapy for patients with metastatic or oligometastatic cancer and aim to guide today's clinical practice and the design of future clinical trials.

PSMA-PET/CT-guided salvage radiotherapy in recurrent or persistent prostate cancer and PSA < 0.2 ng/ml.

PURPOSE: The purpose of this retrospective, multicenter study was to assess efficacy of PSMA-PET/CT-guided salvage radiotherapy (sRT) in patients with recurrent or persistent PSA after primary surgery and PSA levels < 0.2 ng/ml. METHODS: The study included patients from a pooled cohort (n = 1223) of 11 centers from 6 countries. Patients with PSA levels > 0.2 ng/ml prior to sRT or without sRT to the prostatic fossa were excluded. The primary study endpoint was biochemical recurrence-free survival (BRFS) and BR was defined as PSA nadir after sRT + 0.2 ng/ml. Cox regression analysis was performed to assess the impact of clinical parameters on BRFS. Recurrence patterns after sRT were analyzed. RESULTS: The final cohort consisted of 273 patients; 78/273 (28.6%) and 48/273 (17.6%) patients had local or nodal recurrence on PET/CT. The most frequently applied sRT dose to the prostatic fossa was 66-70 Gy (n = 143/273, 52.4%). SRT to pelvic lymphatics was delivered in 87/273 (31.9%) patients and androgen deprivation therapy was given to 36/273 (13.2%) patients. After a median follow-up time of 31.1 months (IQR: 20-44), 60/273 (22%) patients had biochemical recurrence. The 2- and 3-year BRFS was 90.1% and 79.2%, respectively. The presence of seminal vesicle invasion in surgery (p = 0.019) and local recurrences in PET/CT (p = 0.039) had a significant impact on BR in multivariate analysis. In 16 patients, information on recurrence patterns on PSMA-PET/CT after sRT was available and one had recurrent disease inside the RT field. CONCLUSION: This multicenter analysis suggests that implementation of PSMA-PET/CT imaging for sRT guidance might be of benefit for patients with very low PSA levels after surgery due to promising BRFS rates and a low number of relapses within the sRT field.

Imaging-Based Prevalence of Oligometastatic Disease: A Single-Center Cross-Sectional Study.

PURPOSE: Oligometastatic disease refers to a distinct state in patients with cancer characterized by a low metastatic burden, with diagnosis being informed by a limited number of distant metastases in radiologic imaging. However, oligometastasis remains poorly understood in terms of its biology and prevalence in the metastatic cascade. In the absence of clinically viable molecular biomarkers, this study examined the prevalence of oligometastasis using oncological imaging. METHODS AND MATERIALS: This study is based on all consecutive [fluorine-18]-fluorodeoxyglucose (FDG)- and [gallium-68]-prostate specific membrane antigen (PSMA)-positron emission tomography (PET) scans conducted at our cancer center between January and December 2020. We identified and analyzed all PET scans from patients with a maximum of 5 distant metastases from a solid malignancy and also reviewed concurrent cranial magnetic resonance imaging (cMRI) imaging in all candidate patients. Data on the number and sites of metastases were extracted from the imaging reports and verified on imaging studies in case of uncertainties. RESULTS: In total, 7000 PET scans were analyzed, of which 1155 were performed in unique metastatic patients, and 637 patients showed extracranial oligometastatic disease (55%). Concurrent cMRI scans were available for 20% (130/637) of extracranial oligometastatic patients, 36 of which proved to be polymetastatic after combined PET and cMRI analysis. Prevalence of oligometastatic disease was influenced by primary tumor histology and was most frequent in pancreatic, liver and gallbladder cancers (59%), but was least frequent in cancer of unknown primary (26%). In 72% of oligometastatic cases, only 1 or 2 metastases were detected. Bone/soft tissue metastases were the most common sites of distant metastasis (41%). About 75% of patients had metachronous oligometastatic disease. CONCLUSIONS: Our analysis suggests that about half of patients with metastatic cancer are characterized by a limited tumor burden detectable on PET and cMRI imaging. This finding warrants intensified research efforts to better understand the biology of oligometastatic disease and to optimize multidisciplinary treatment strategies.

Evaluation of the prognostic value of the ESTRO EORTC classification of oligometastatic disease in patients treated with stereotactic body radiotherapy: A retrospective single center study.

PURPOSE: To explore the prognostic value of the oligometastatic disease (OMD) states as proposed by the European Society for Radiotherapy and Oncology (ESTRO) European Organisation for Research and Treatment of Cancer (EORTC) classification system. MATERIALS AND METHODS: This retrospective single-institution study included patients with 1-5 extracranial metastases from any solid malignancy treated with SBRT to all metastases. OMD states were defined according to the ESTRO EORTC classification. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method. Discriminatory strength of the classification was assessed by Gönen & Heller's concordance probability estimate (CPE). Univariable and multivariable Cox regression models were used to assess predictors of OS and PFS. RESULTS: In total, 385 patients were included. The median follow-up was 24.1 months. The most frequent OMD states were metachronous oligorecurrence (23.6%) and induced oligoprogression (18.7%). Induced OMD patients had significantly shorter median OS (28.1 months) compared with de-novo (46.3 months, p = 0.002) and repeat OMD (50.3 months, p = 0.002). Median PFS in de-novo OMD patients (8.8 months) was significantly longer than in repeat (5.4 months, p = 0.002) and induced OMD patients (4.3 months, p < 0.001). The classification system had moderate discriminatory strength for OS and PFS. Multivariable analyses confirmed that compared with induced OMD, de-novo OMD was associated with longer PFS and repeat with longer OS. CONCLUSION: All patients were successfully categorized according to the ESTRO EORTC classification system. The discriminatory strength of the classification was confirmed for OMD patients treated with metastases-directed SBRT. Larger multicenter trials are needed to validate the prognostic power for OMD patients irrespective of primary tumor and treatment approach.

True abscopal effect in a patient with metastatic non-small cell lung cancer.

BACKGROUND: Systemic response to local anticancer treatment is a phenomenon called 'abscopal effect'. The immune system is thought to play a pivotal role in its occurrence. To date, several cases have been reported, particularly in patients receiving combined local treatment and immune checkpoint inhibitors. In such cases, it is impossible to discriminate between the effects of local and systemic treatment. Only a few cases of abscopal effect have been described with radiotherapy alone. CASE PRESENTATION: Here, we report on the case of an 81-year-old woman with recurrent metastatic squamous cell carcinoma of the lung with mediastinal tumor bulk, lymph node and bone metastases. The patient refused to undergo systemic treatment, and palliative stereotactic radiotherapy of the mediastinal tumor was performed. At restaging with FDG-PET/CT, the patient presented with a decrease in size and FDG-avidity both of the irradiated site and of the lymph node and bone metastases (which did not receive radiotherapy). At 25 months after radiotherapy, the patient is still in remission at all sites. CONCLUSIONS: This is a rare case of an abscopal effect after radiotherapy as monotherapy. It is one of the few hitherto reported for lung cancer. Several ongoing studies with a combination of radiotherapy and immunotherapy are seeking to exploit a potential synergy to induce abscopal effects.

Continued versus Interrupted Targeted Therapy during Metastasis-Directed Stereotactic Radiotherapy: A Retrospective Multi-Center Safety and Efficacy Analysis.

The increasing use of targeted therapy (TT) has resulted in prolonged disease control and survival in many metastatic cancers. In parallel, stereotactic radiotherapy (SRT) is increasingly performed in patients receiving TT to obtain a durable control of resistant metastases, and thereby to prolong the time to disseminated disease progression and switch of systemic therapy. The aims of this study were to analyze the safety and efficacy of SRT combined with TT in metastatic cancer patients and to assess the influence of continuous vs. interrupted TT during metastasis-directed SRT. The data of 454 SRTs in 158 patients from the international multicenter database (TOaSTT) on metastatic cancer patients treated with SRT and concurrent TT (within 30 days) were analyzed using Kaplan-Meier and log rank testing. Toxicity was defined by the CTCAE v4.03 criteria. The median FU was 19.9 mo (range 1-102 mo); 1y OS, PFS and LC were 59%, 24% and 84%, respectively. Median TTS was 25.5 mo (95% CI 11-40). TT was started before SRT in 77% of patients. TT was interrupted during SRT in 44% of patients, with a median interruption of 7 (range 1-42) days. There was no significant difference in OS or PFS whether TT was temporarily interrupted during SRT or not. Any-grade acute and late SRT-related toxicity occurred in 63 (40%) and 52 (33%) patients, respectively. The highest toxicity rates were observed for the combination of SRT and EGFRi or BRAF/MEKi, and any-grade toxicity was significantly increased when EGFRi (p = 0.016) or BRAF/MEKi (p = 0.009) were continued during SRT. Severe (≥grade 3) acute and late SRT-related toxicity were observed in 5 (3%) and 7 (4%) patients, respectively, most frequently in patients treated with EGFRi or BRAF/MEKi and in the intracranial cohort. There was no significant difference in severe toxicity whether TT was interrupted before and after SRT or not. In conclusion, SRT and continuous vs. interrupted TT in metastatic cancer patients did not influence OS or PFS. Overall, severe toxicity of combined treatment was rare; a potentially increased toxicity after SRT and continuous treatment with EGFR inhibitors or BRAF(±MEK) inhibitors requires further evaluation.

A Prospective Study on Health-Related Quality of Life and Patient-Reported Outcomes in Adult Brain Tumor Patients Treated with Pencil Beam Scanning Proton Therapy.

Proton therapy (PT) is delivered to complex brain tumors to obtain an optimal curative treatment with limited toxicity. Value-based oncological medicine is increasingly important, particularly when long-term survival is to be expected. This study aims to evaluate health-related quality of life (HRQOL) and patient reported outcomes (PROs) in patients treated with PT for brain tumors. Adult patients with brain tumors treated with PT filled out the EORTC-QLQ-C30 and BN20 questionnaires up to three years following PT. Toxicity was scored using the CTCAE v4.03. QoL and PRO were correlated to clinical factors. Three-year overall survival, distant brain control and local control rates were 98%, 97% and 84%, respectively. No ≥G3 acute toxicity was observed. Late PT-related ≥G3 severe toxicity occurred in seven patients (5.7%). Lower global QoL scores after PT were significantly correlated to low Karnofsky performance status (KPS) before PT (p = 0.001), surgical complications before PT (p = 0.04) and progressive disease (p = 0.017). A low QLQ-30 summary score at one year follow-up was correlated to sex (p = 0.015), low KPS before PT (p < 0.001), and central nervous system symptoms before PT (p = 0.018). Reported QLQ-BN20 neurological symptoms were correlated to lower KPS at baseline (p < 0.001) and surgical complications before PT (p = 0.03). PT-related toxicity only influenced reported symptoms directly following PT, but not QoL. Although global QoL temporarily decreased after treatment, it improved again from one year onwards. Global QoL and reported symptoms over time were not correlated with the proton therapy and were more related to preexisting symptoms and progressive disease. This study assists in improving patient support in patients with brain tumors receiving PT.

Combining 68Ga-PSMA-PET/CT-Directed and Elective Radiation Therapy Improves Outcome in Oligorecurrent Prostate Cancer: A Retrospective Multicenter Study.

BACKGROUND: In case of oligo-recurrent prostate cancer (PC) following prostatectomy, 68Ga-PSMA-PET/CT can be used to detect a specific site of recurrence and to initiate metastasis-directed radiation therapy (MDT). However, large heterogeneities exist concerning doses, treatment fields and radiation techniques, with some studies reporting focal radiotherapy (RT) to PSMA-PET/CT positive lesions only and other studies using elective RT strategies. We aimed to compare oncological outcomes and toxicity between PET/CT-directed RT (PDRT) and PDRT plus elective RT (eRT; i.e. prostate bed, pelvic or paraaortal nodes) in a large retrospective multicenter study. METHODS: Data of 394 patients with oligo-recurrent 68Ga-PSMA-PET/CT-positive PC treated between 04/2013 and 01/2018 in six different academic institutions were evaluated. Primary endpoint was biochemical-recurrence-free survival (bRFS). bRFS was analyzed using Kaplan-Meier survival curves and log rank testing. Uni- and multivariate analyses were performed to determine influence of treatment parameters. RESULTS: In 204 patients (51.8%) RT was directed only to lesions seen on 68Ga-PSMA-PET/CT (PDRT), 190 patients (48.2%) received PDRT plus eRT. PDRT plus eRT was associated with a significantly improved 3-year bRFS compared to PDRT alone (53 vs. 37%; p = 0.001) and remained an independent factor in multivariate analysis (p = 0.006, HR 0.29, 95% CI 0.12-0.68). This effect was more pronounced in the subgroup of patients who were treated with PDRT and elective prostate bed radiotherapy (ePBRT) with a 3-year bRFS of 61% versus 22% (p <0.001). Acute and late toxicity grade ≥3 was 0.8% and 3% after PDRT plus eRT versus no toxicity grade ≥3 after PDRT alone. CONCLUSIONS: In this large cohort of patients with oligo-recurrent prostate cancer, elective irradiation of the pelvic lymphatics and the prostatic bed significantly improved bRFS when added to 68Ga-PSMA-PET/CT-guided focal radiotherapy. These findings need to be evaluated in a randomized controlled trial.

Metastasis directed stereotactic radiotherapy in NSCLC patients progressing under targeted- or immunotherapy: efficacy and safety reporting from the 'TOaSTT' database.

BACKGROUND: Metastasis directed treatment (MDT) is increasingly performed with the attempt to improve outcome in non-small cell lung cancer (NSCLC) patients receiving targeted- or immunotherapy (TT/IT). This study aimed to assess the safety and efficacy of metastasis directed stereotactic radiotherapy (SRT) concurrent to TT/IT in NSCLC patients. METHODS: A retrospective multicenter cohort of stage IV NSCLC patients treated with TT/IT and concurrent (≤ 30 days) MDT was established. 56% and 44% of patients were treated for oligoprogressive disease (OPD) or polyprogressive disease (PPD) under TT/IT, polyprogressive respectively. Survival was analyzed using Kaplan-Meier and log rank testing. Toxicity was scored using CTCAE v4.03 criteria. Predictive factors for overall survival (OS), progression free survival (PFS) and time to therapy switch (TTS) were analyzed with uni- and multivariate analysis. RESULTS: MDT of 192 lesions in 108 patients was performed between 07/2009 and 05/2018. Concurrent TT/IT consisted of EGFR/ALK-inhibitors (60%), immune checkpoint inhibitors (31%), VEGF-antibodies (8%) and PARP-inhibitors (1%). 2y-OS was 51% for OPD and 25% for PPD. After 1 year, 58% of OPD and 39% of PPD patients remained on the same TT/IT. Second progression after MDT was oligometastatic (≤ 5 lesions) in 59% of patients. Severe acute and late toxicity was observed in 5.5% and 1.9% of patients. In multivariate analysis, OS was influenced by the clinical metastatic status (p = 0.002, HR 2.03, 95% CI 1.30-3.17). PFS was better in patients receiving their first line of systemic treatment (p = 0.033, HR 1.7, 95% CI 1.05-2.77) and with only one metastases-affected organ (p = 0.023, HR 2.04, 95% CI 1.10-3.79). TTS was 6 months longer in patients with one metastases-affected organ (p = 0.031, HR 2.53, 95% CI 1.09-5.89). Death was never therapy-related. CONCLUSIONS: Metastases-directed SRT in NSCLC patients can be safely performed concurrent to TT/IT with a low risk of severe toxicity. To find the ideal sequence of the available multidisciplinary treatment options for NSCLC and determine what patients will benefit most, a further evaluated in a broader context within prospective clinical trials is needed continuation of TT/IT beyond progression combined with MDT for progressive lesions appears promising but requires prospective evaluation. TRIAL REGISTRATION: retrospectively registered.

Prostate-specific Membrane Antigen Positron Emission Tomography-detected Oligorecurrent Prostate Cancer Treated with Metastases-directed Radiotherapy: Role of Addition and Duration of Androgen Deprivation.

BACKGROUND: Approximately 40-70% of biochemically recurrent prostate cancer (PCa) is oligorecurrent after prostate-specific membrane antigen (PSMA) positron emission tomography (PET) staging. Metastasis-directed radiotherapy (MDT) of PSMA-positive oligorecurrence is now frequently used, but the role of concurrent androgen deprivation therapy (ADT) remains unclear. OBJECTIVE: To determine the effect of concurrent ADT with PSMA PET-directed MDT on biochemical progression-free survival (bRFS). DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective multicenter study of 305 patients with biochemical recurrence and PSMA PET-positive oligorecurrence following initial curative treatment between April 2013 and January 2018. INTERVENTION: MDT with fractionated or stereotactic body radiotherapy for all PSMA-positive metastatic sites; 37.8% received concurrent ADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was bRFS, which was measured using Kaplan-Meier curves and log-rank testing. Secondary outcomes were ADT-free survival, overall survival (OS), and toxicity was analyzed using the Common Terminology Criteria for Adverse Events v4.03. Univariate and multivariate analyses were performed to determine independent clinicopathological factors. RESULTS AND LIMITATIONS: The median follow-up was 16 mo (interquartile range 9-27). Some 96% of the patients initially had high-risk PCa. A median of one (range 0-19) nodal metastases and one (range 0-5) distant metastases were treated. MDT+ADT significantly improved bRFS and remained an independent factor (hazard ratio 0.28, 95% confidence interval 0.16-0.51; p<0.0001). bRFS was not significantly different between MDT+≤6 mo of ADT and MDT alone (p=0.121). Patients receiving MDT had 1- and 2-yr ADT-free survival of 93% and 83%, respectively. New therapies, most frequently MDT (23%), were required more frequently after MDT (85% vs 29%; p<0.001). Grade ≥3 acute toxicity was observed in 0.9% of patients and late toxicity in 2.3%. CONCLUSIONS: In this cohort of patients with oligorecurrent PCa, concurrent ADT with MDT improved bRFS significantly, but a large number of patients treated with MDT were spared from ADT for 2yr, although a greater need for other salvage therapies was observed. PATIENT SUMMARY: The role of concurrent androgen deprivation therapy (ADT) with radiotherapy for prostate cancer oligorecurrence identified on prostate-specific membrane antigen positron emission tomography was studied. We concluded that radiotherapy alone could prolong the time to start of ADT. However, the risk of disease progression and consequently the need for further treatments is higher after local radiotherapy alone without immediate ADT.

Stereotactic radiotherapy combined with immunotherapy or targeted therapy for metastatic renal cell carcinoma.

OBJECTIVES: To evaluate the safety and efficacy of stereotactic radiotherapy (SRT) in patients with metastatic renal cell carcinoma (mRCC) concurrently receiving targeted therapy (TT) or immunotherapy. PATIENTS AND METHODS: Data on patients with mRCC were extracted from a retrospective international multicentre register study (TOaSTT), investigating SRT concurrent (≤30 days) with TT/immune checkpoint inhibitor (ICI) therapy. Overall survival (OS), progression-free survival (PFS), local metastasis control (LC) and time to systemic therapy switch were analysed using Kaplan-Meier curves and log-rank testing. Clinical and treatment factors influencing survival were analysed using multivariate Cox regression. Acute and late SRT-induced toxicity were defined according to the Common Terminology Criteria for Adverse Events v.4.03. RESULTS: Fifty-three patients who underwent 128 sessions of SRT were included, of whom 58% presented with oligometastatic disease (OMD). ICIs and TT were received by 32% and 68% of patients, respectively. Twenty patients (37%) paused TT for a median (range) of 14 (2-21) days. ICI therapy was not paused in any patient. A median (range) of 1 (1-5) metastatic tumour was treated per patient, with a median (range) SRT dose of 65 (40-129.4) Gy (biologically effective dose). The OS, LC and PFS rates at 1 year were 71%, 75% and 25%, respectively. The median OS and PFS were not significantly different among patients receiving TT vs those receiving ICIs (P = 0.329). New lesions were treated with a repeat radiotherapy course in 46% of patients. After 1 year, 62% of patients remained on the same systemic therapy as at the time of SRT; this was more frequent for ICI therapy compared to TT (83% vs 36%; P = 0.035). OMD was an independent prognostic factor for OS (P = 0.004, 95% confidence interval [CI] 0.035-0.528) and PFS (P = 0.004; 95% CI 0.165-0.717) in multivariate analysis. Eastern Cooperative Oncology Group performance status (ECOG-PS) was the other independent prognostic factor for OS (P = 0.001, 95% CI 0.001-0.351). Acute grade 3 toxicity was observed in two patients, and late grade 3 toxicity in one patient. No grade 4 or 5 toxicity was observed. CONCLUSION: Combined treatment with TT or immunotherapy and concurrent SRT was safe, without signals of increased severe toxicity. As we observed no signal of excess toxicity, full-dose SRT should be considered to achieve optimal metastasis control in patients receiving TT or immunotherapy. Favourable PFS and OS were observed for patients with oligometastatic RCC with a good ECOG-PS, which should form the basis for prospective testing of this treatment strategy in properly designed clinical trials.

Outcomes of adolescents and young adults treated for brain and skull base tumors with pencil beam scanning proton therapy.

BACKGROUND: The use of proton therapy (PT) in adolescents and young adults (AYAs) is becoming increasingly popular. This study aims to assess the outcomes and late toxicity consequences in AYAs (15-39 years) with brain/skull base tumors treated with pencil beam scanning proton therapy. METHODS: One hundred seventy six AYAs treated curatively at the Paul Scherrer Institute (PSI) were identified. Median age was 30 years (range 15-39) and median prescribed dose was 70.0 Gy (relative biological effectiveness [RBE]) (range 50.4-76.0). The most common tumors treated were chordomas/chondrosarcomas (61.4%), followed by gliomas (15.3%), and meningiomas (14.2%). RESULTS: After a median follow up of 66 months (range 12-236), 24 (13.6%) local only failures and one (0.6%) central nervous system (CNS) distant only failure were observed. The 6-year local control, distant progression-free survival, and overall survival were 83.2%, 97.4%, and 90.2%, respectively. The 6-year high-grade (≥grade [G] 3) PT-related late toxicity-free survival was 88.5%. Crude late toxicity rates were 26.2% G1, 37.8% G2, 12.2% G3, 0.6% G4, and 0.6% G5. The one G4 toxicity was a retinopathy and one G5 toxicity was a brainstem hemorrhage. The 6-year cumulative incidences for any late PT-related pituitary, ototoxicity, and neurotoxicity were 36.3%, 18.3%, and 25.6%; whilst high-grade (≥G3) ototoxicity and neurotoxicity were 3.4% and 2.9%, respectively. No secondary malignancies were observed. The rate of unemployment was 9.5% pre-PT, increasing to 23.8% post-PT. Sixty-two percent of survivors were working whilst 12.7% were in education post-PT. CONCLUSIONS: PT is an effective treatment for brain/skull base tumors in the AYA population with a reasonable late toxicity profile. Despite good clinical outcomes, around one in four AYA survivors are unemployed after treatment.

Predicting survival in melanoma patients treated with concurrent targeted- or immunotherapy and stereotactic radiotherapy : Melanoma brain metastases prognostic score.

BACKGROUND: Melanoma patients frequently develop brain metastases. The most widely used score to predict survival is the molGPA based on a mixed treatment of stereotactic radiotherapy (SRT) and whole brain radiotherapy (WBRT). In addition, systemic therapy was not considered. We therefore aimed to evaluate the performance of the molGPA score in patients homogeneously treated with SRT and concurrent targeted therapy or immunotherapy (TT/IT). METHODS: This retrospective analysis is based on an international multicenter database (TOaSTT) of melanoma patients treated with TT/IT and concurrent (≤30 days) SRT for brain metastases between May 2011 and May 2018. Overall survival (OS) was studied using Kaplan-Meier survival curves and log-rank testing. Uni- and multivariate analysis was performed to analyze prognostic factors for OS. RESULTS: One hundred ten patients were analyzed. 61, 31 and 8% were treated with IT, TT and with a simultaneous combination, respectively. A median of two brain metastases were treated per patient. After a median follow-up of 8 months, median OS was 8.4 months (0-40 months). The molGPA score was not associated with OS. Instead, cumulative brain metastases volume, timing of metastases (syn- vs. metachronous) and systemic therapy with concurrent IT vs. TT influenced OS significantly. Based on these parameters, the VTS score (volume-timing-systemic therapy) was established that stratified patients into three groups with a median OS of 5.1, 18.9 and 34.5 months, respectively (p = 0.001 and 0.03). CONCLUSION: The molGPA score was not useful for this cohort of melanoma patients undergoing local therapy for brain metastases taking into account systemic TT/IT. For these patients, we propose a prognostic VTS score, which needs to be validated prospectively.