Early Toxicity of a Phase 2 Trial of Combined Salvage Radiation Therapy and Hormone Therapy in Oligometastatic Pelvic Node Relapses of Prostate Cancer (OLIGOPELVIS GETUG P07)

PEACE V-Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): Acute Toxicity of a Randomized Phase 2 Trial

BACKGROUND

Treatment recommendations for patients with limited nodal recurrences are lacking, and different locoregional treatment approaches are currently being used.

OBJECTIVE

The aim of this trial is to compare metastasis-directed therapy (MDT) with or without elective nodal pelvic radiotherapy (ENRT).

DESIGN, SETTING, AND PARTICIPANTS

PEACE V-Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM) is an international, phase 2, open-label, randomized, superiority trial (ClinicalTrials.gov identifier: NCT03569241). Patients diagnosed with positron emission tomography-detected pelvic nodal oligorecurrence (five or fewer nodes) following radical local treatment for prostate cancer were randomized in a 1:1 ratio between arm A (MDT and 6 mo of androgen deprivation therapy [ADT]) and arm B (ENRT [25 × 1.8 Gy] with MDT and 6 mo of ADT).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We report the secondary endpoint acute toxicity, defined as worst grade ≥2 Common Terminology Criteria for Adverse Events v4.0 gastrointestinal (GI) or genitourinary (GU) toxicity within 3 mo of treatment. The chi-square test was used to compare toxicity between treatment arms. We also compare the quality of life (QoL) using the European Organisation for Research and Treatment of Cancer QLQ C30 and PR25 questionnaires.

RESULTS AND LIMITATIONS

Between June 2018 and April 2021, 196 patients were assigned randomly to MDT or ENRT. Ninety-seven of 99 patients allocated to MDT and 93 of 97 allocated to ENRT received per-protocol treatment. Worst acute GI toxicity proportions were as follows: grade ≥2 events in three (3%) in the MDT group versus four (4%) in the ENRT group (p = 0.11). Worst acute GU toxicity proportions were as follows: grade ≥2 events in eight (8%) in the MDT group versus 12 (13%) in the ENRT group (p = 0.95). We observed no significant difference between the study groups in the proportion of patients with a clinically significant QoL reduction from baseline for any subdomain score area.

CONCLUSIONS

No clinically meaningful differences were observed in worst grade ≥2 acute GI or GU toxicity or in QoL subdomains between MDT and ENRT.

PATIENT SUMMARY

We found no evidence of differential acute bowel or urinary side effects using metastasis-directed therapy and elective nodal radiotherapy for the treatment of patients with a pelvic lymph node recurrence.

Long-term Outcomes and Patterns of Relapse Following High-dose Elective Salvage Radiotherapy and Hormone Therapy in Oligorecurrent Pelvic Nodes in Prostate Cancer: OLIGOPELVIS (GETUG-P07)

Androgen deprivation therapy (ADT) is a mainstay of treatment for metastatic prostate cancer, while additional salvage radiotherapy may offer prolonged remission for patients with regional node relapses. We report 5-yr outcomes from OLIGOPELVIS (GETUG-P07), an open-label phase 2 trial assessing long-term outcomes and patterns of relapse after 6-mo ADT and elective nodal radiotherapy (ENRT) in men with pelvic nodal oligorecurrence (<6 lesions) of prostate cancer. Progression was defined as two consecutive prostate-specific antigen (PSA) levels above the level at inclusion and/or clinical progression according to Response Evaluation Criteria in Solid Tumors v1.1 and/or death from any cause. Sixty-seven patients were recruited. Median follow-up was 6.1 yr (95% confidence interval 5.9-6.3). Rates of grade 2+ toxicities among patients without progression at 3, 4, and 5 yr were 15%, 9%, and 4% for genitourinary toxicities, and 2%, 3%, and 4% for gastrointestinal toxicities, respectively. The 5-yr progression-free, biochemical relapse-free, and ADT-free survival rates were 39%, 31%, and 64%, respectively. In total, 45 patients experienced progression, which was PSA-only progression in seven cases. Among the other 38 patients, local clinical progression occurred in 18%, progression to N1 stage in 29%, to M1a stage in 50%, to M1b stage in 32%, and to M1c stage in 11%. Finally, combined ENRT and ADT appeared to prolong tumor control with limited toxicity. At 5 yr, one-third of the patients had not experienced biochemical relapse. The major site of relapse was the para-aortic lymph nodes. PATIENT SUMMARY: We evaluated long-term results for high-dose radiotherapy in patients with recurrence of prostate cancer in pelvic lymph nodes. We found that this treatment provided prolonged tumor control without significant toxicity. One-third of the patients were still in complete remission after 5 years.

The Efficacy and Safety of Metastasis-directed Therapy in Patients with Prostate Cancer: A Systematic Review and Meta-analysis of Prospective Studies

CONTEXT

Despite the lack of level 1 evidence, metastasis-directed therapy (MDT) is used widely in the management of metastatic prostate cancer (mPCa) patients. Data are continuously emerging from well-designed prospective studies.

OBJECTIVE

To summarise and report the evidence on oncological and safety outcomes of MDT in the management of mPCa patients.

EVIDENCE ACQUISITION

We searched the PubMed, Scopus, and Web of Science databases for prospective studies assessing progression-free survival (PFS), local control (LC), androgen deprivation therapy (ADT)-free survival (ADT-FS), overall survival (OS), and/or adverse events (AEs) in mPCa patients treated with MDT. A meta-analysis was performed for 1- and 2-yr PFS, LC, ADT-FS, OS, and rate of AEs. Meta-regression and sensitivity analysis were performed to account for heterogeneity and identify moderators.

EVIDENCE SYNTHESIS

We identified 22 prospective studies (n = 1137), including two randomised controlled trials (n = 116). Two studies were excluded from the meta-analysis (n = 120). The estimated 2-yr PFS was 46% (95% confidence interval [CI]: 36-56%) or 42% (95% CI: 33-52%) after excluding studies using biochemical or ADT-related endpoints. The estimated 2-yr LC, ADT-FS, and OS were 97% (95% CI: 94-98%), 55% (95% CI: 44-65%), and 97% (95% CI: 95-98%), respectively. Rates of treatment-related grade 2 and ≥3 AEs were 2.4% (95% CI: 0.2-7%) and 0.3% (95% CI: 0-1%), respectively.

CONCLUSIONS

MDT is a promising treatment strategy associated with favourable PFS, excellent LC, and a low toxicity profile that allows oligorecurrent hormone-sensitive patients to avoid or defer ADT-related toxicity. Integration of MDT with other therapies offers a promising research direction, in particular, in conjunction with systemic treatments and as a component of definitive care for oligometastatic PCa. However, in the absence of randomised trials, using MDT for treatment intensification remains an experimental approach, and the impact on OS is uncertain.

PATIENT SUMMARY

Direct treatment of metastases is a promising option for selected prostate cancer patients. It can delay hormone therapy and is being investigated as a way of intensifying treatment at the expense of manageable toxicity.

Extended nodal radiotherapy for prostate cancer relapse guided with [11C]-choline PET/CT: ten-year results in patients enrolled in a prospective trial

AIMS

To report long-term outcomes of relapsed prostate cancer (PC) patients treated in a prospective single-arm study with extended-nodal radiotherapy (ENRT) and [11C]-choline positron emission tomography (PET)/computed tomography (CT)-guided simultaneous integrated boost (SIB) to positive lymph nodes (LNs).

METHODS

From 12/2009 to 04/2015, 60 PC patients with biochemical relapse and positive LNs only were treated in this study. ENRT at a median total dose (TD) = 51.8 Gy/28 fr and PET/CT-guided SIB to positive LNs at a median TD = 65.5 Gy was prescribed. Median PSA at relapse was 2.3 (interquartile range, IQR:1.3-4.0) ng/ml. Median number of positive LNs: 2 (range: 1-18). Androgen deprivation therapy (ADT) was prescribed for 48 patients for a median of 30.7 (IQR: 18.5-43.1) months.

RESULTS

Median follow-up from the end of salvage treatment was 121.8 (IQR: 116.1, 130.9) months; 3-, 5-, and 10-year BRFS were 45.0%, 36.0%, and 24.0%, respectively; DMFS: 67.9%, 57.2%, and 45.2%; CRFS: 62.9%, 53.9%, and 42.0%; and OS: 88.2%, 76.3%, and 47.9%, respectively. Castration resistance (p < 0.0001) and ≥ 6 positive LN (p = 0.0024) significantly influenced OS at multivariate analysis. Castration resistance (p < 0.0001 for both) influenced DMFS and CRFS in multivariate analysis.

CONCLUSIONS

In PC relapsed patients treated with ENRT and [11C]-choline-PET/CT-guided SIB for positive LNs, with 10-year follow-up, a median Kaplan-Meier estimate CRFS of 67 months and OS of 110 months were obtained. These highly favorable results should be confirmed in a prospective, randomized trial.

Elective nodal radiotherapy with a gapless radiation field junction for oligorecurrent prostate cancer after previous radiotherapy

Purpose

To evaluate the feasibility of subsequent elective nodal radiotherapy (ENRT) for nodal recurrences after previous radiotherapy with a defined planning approach for a gapless radiation field junction.

Methods

Patients with 1) previous radiotherapy of prostate or prostatic fossa and subsequent pelvic ENRT or 2) previous pelvic radiotherapy and subsequent ENRT to paraaortic lymph nodes (LN) and gapless junction of both radiation fields were analyzed. The cumulative maximum dose (D_max-cum) and the maximum cumulative dose in 1 cc (D_1cc-cum) were estimated. Absolute toxicity and the toxicity exceeding baseline were evaluated.

Results

Twenty-two patients with PSMA-PET/CT-staged nodal oligorecurrence after prior radiotherapy were treated with pelvic (14 patients) or paraaortic ENRT (9 patients). One patient was treated sequentially at both locations. Median time between first and second RT was 20.2 months. Median doses to the lymphatic pathways and to PET-positive LN were 47.5 Gy and 64.8 Gy, respectively. The planning constraint of an estimated D_max-cum ≤ 95 Gy and of D_1cc-cum < 90 Gy were achieved in 23/23 cases and 22/23 cases, respectively. Median follow-up was 33.5 months. There was no additional acute or late toxicity ≥ grade 3. Worst acute toxicity exceeding baseline was grade 1 in 68.2% and grade 2 in 22.7% of patients. Worst late toxicity exceeding baseline was grade 1 in 31.8% and grade 2 in 18.2% of patients.

Conclusion

ENRT for nodal recurrences after a previous radiotherapy with gapless junction of radiation fields seems to be feasible, applying the dose constraints D_max-cum ≤ 95 Gy and D_1cc-cum < 90 Gy without grade 3 acute or late toxicities exceeding baseline.

[Intermediate-risk prostate cancer treated with exclusive external irradiation: Focus on anatomical sites of recurrence in two French trials]

PURPOSE

Retrospective description of anatomical sites of relapse based on (18F)-choline PET-CT, (68Ga)-prostatic specific-membrane antigen PET-CT, bone scan, and prostate magnetic resonance imaging (MRI) data.

MATERIALS AND METHODS

From two French prospective cohorts, patients treated with exclusive radiotherapy for an intermediate-risk cancer were identified during their follow-ups. They were included if they presented a rising of the prostate-specific antigen (PSA) associated with the realization of an imaging showing the sites of recurrences.

RESULTS

Two hundred and sixty-three patients were included. After a median follow-up of 76 months (interquartile range [IQR] 67-95), 65 patients had biochemical recurrence and positive imaging. The median nadir PSA was 0.6ng/mL and the median PSA at recurrence was 3.4ng/mL. A single lesion was found in 48% of cases, 2 to 4 lesions in 43% of cases and more than 4 lesions in 9% of cases. The sites of relapse identified were prostate (37/65), prostate only (19/65), seminal vesicles (9/65) Pelvic nodes (35/65), extrapelvic nodes (15/65) and bone (13/65).

CONCLUSIONS

The majority of relapses presented as a single lesion localized in the pelvis.

Ga-68-PSMA-11 PET/CT in Patients with Biochemical Recurrence of Prostate Cancer after Primary Treatment with Curative Intent-Impact of Delayed Imaging

The presence of prostate-specific membrane antigen (PSMA) on prostate cancer cells and its metastases allows its use in diagnostics using PET/CT. The aim of this study was to evaluate the usefulness of delayed phase images in the Ga-68-PSMA-11 PET/CT. Methods: 108 patients with prostate cancer (median age: 68.5 years, range: 49−83) were referred for Ga-68-PSMA-11 PET/CT due to biochemical relapse (PSA (prostate-specific antigen) (3.2 ± 5.4 ng/mL). Examinations were performed at 60 min, with an additional delayed phase of the pelvis region at 120−180 min. Results: The Ga-68-PSMA-11 PET/CT showed lesions in 86/108 (80%) patients; detection rate depending on the PSA level: 0.2 < PSA < 0.5 ng/mL vs. 0.5 ≤ PSA < 1.0 ng/mL vs. 1.0 ≤ PSA < 2.0 ng/mL vs. PSA ≥ 2.0 ng/mL was 56% (standard vs. delay: 56 vs. 56%) vs. 60% (52 vs. 60%) vs. 87% (83 vs. 87%) vs. 82% (77 vs. 82%) of patients, respectively. The delayed phase had an impact on the treatment in 14/86 patients (16%) (p < 0.05): 7 pts increased uptake was seen only after 60 min, which was interpreted as physiological or inflammatory accumulation; the delayed image showed increased accumulation in 7 patients only: 4 in regional lymph nodes, 1 in local recurrence, and 2 patients with local recurrence showed additional foci. Conclusions: Delayed phase of Ga-68-PSMA-11 PET/CT has an impact on treatment management in 16% of patients.

Drug Intensification in Future Postoperative Radiotherapy Practice in Biochemically-Relapsing Prostate Cancer Patients

Although salvage prostate bed radiotherapy is highly effective in biochemically-relapsing prostate cancer patients following prostatectomy, relapses remain frequent and improvements are needed. Randomized phase 3 trials have shown the benefit of adding androgen-depriving therapy to irradiation, but not all patients benefit from this combination. Preclinical studies have shown that novel agents targeting the androgen receptor, DNA repair, PI3K/AKT/mTOR pathways, or the hypoxic microenvironment may help increase the response to prostate bed irradiation while minimizing potential side effects. This perspective review focuses on the most relevant molecules that may have an impact when combined with salvage radiotherapy, and underlines the strategies that need to be developed to increase the efficacy of salvage post-prostatectomy radiotherapy in prostate cancer patients.

Should androgen deprivation therapy and other systemic treatments be used in men with prostate cancer and a rising PSA post-local treatments?

Biochemical recurrence is an evolving space in prostate cancer, with increasing multidisciplinary involvement. Androgen deprivation therapy has shown proof of its value in complementing salvage radiotherapy in high-risk biochemical relapsing patients; ongoing trials aim to further refine this treatment combination. As systemic treatments, and notably next-generation androgen receptor targeted agents, have moved towards early hormone-sensitive and non-metastatic stages, the prostate specific antigen (PSA)-relapse disease stage will be undoubtedly challenged by future evidence from such ongoing clinical trials. With the use of modern imaging and newer molecular technologies, including integration of tumoral genomic profiling and liquid biopsies in risk stratification, a path towards a precision oncology-focused approach will become a reality to guide in the future decisions for patients with a diagnosis of biochemical recurrence.

PET/CT-Based Salvage Radiotherapy for Recurrent Prostate Cancer After Radical Prostatectomy: Impact on Treatment Management and Future Directions

Biochemical recurrence is a clinical situation experienced by 20 to 40% of prostate cancer patients treated with radical prostatectomy (RP). Prostate bed (PB) radiation therapy (RT) remains the mainstay salvage treatment, although it remains non-curative for up to 30% of patients developing further recurrence. Positron emission tomography with computed tomography (PET/CT) using prostate cancer-targeting radiotracers has emerged in the last decade as a new-generation imaging technique characterized by a better restaging accuracy compared to conventional imaging. By adapting targeting of recurrence sites and modulating treatment management, implementation in clinical practice of restaging PET/CT is challenging the established therapeutic standards born from randomized controlled trials. This article reviews the potential impact of restaging PET/CT on changes in the management of recurrent prostate cancer after RP. Based on PET/CT findings, it addresses potential adaptation of RT target volumes and doses, as well as use of androgen-deprivation therapy (ADT). However, the impact of such management changes on the oncological outcomes of PET/CT-based salvage RT strategies is as yet unknown.

Postoperative radiotherapy in prostate cancer: Dose and volumes

Approximately thirty percent of patients experience biochemical recurrence after radical prostatectomy for prostate cancer. Early salvage radiotherapy has recently become a standard of care in this setting. The purpose of this review is first to summarize current knowledge in terms of dose to the prostate bed in light of the recent SAKK 09/10 randomized phase III trial results. The evidence on moderate hypofractionation will also be discussed whereas extreme hypofractionation remains highly investigational. Regarding target volumes, several different guidelines have been published to address the need for standardization of postoperative target delineation. The recent GFRU (Groupe Francophone de Radiothérapie Urologique) recommendations could represent an international consensus.

Elective nodal radiotherapy in prostate cancer

In patients with prostate cancer who have a high risk of pelvic nodal disease, the use of elective whole pelvis radiotherapy is still controversial. Two large, randomised, controlled trials (RTOG 9413 and GETUG-01) did not show a benefit of elective whole pelvis radiotherapy over prostate-only radiotherapy. In 2020, the POP-RT trial established the role of elective whole pelvis radiotherapy in patients who have more than a 35% risk of lymph node invasion (known as the Roach formula). POP-RT stressed the importance of patient selection. In patients with cN1 (clinically node positive) disease or pN1 (pathologically node positive) disease, the addition of whole pelvis radiotherapy to androgen deprivation therapy significantly improved survival compared with androgen deprivation therapy alone, as shown in large, retrospective studies. This patient population might increase in the future because use of the more sensitive prostate-specific membrane antigen PET-CT will become the standard staging procedure. Additionally, the SPORTT trial suggested a benefit of whole pelvis radiotherapy in biochemical recurrence-free survival in the salvage setting. A correct definition of the upper field border, which should include the bifurcation of the abdominal aorta, is key in the use of pelvic radiotherapy. As a result of using modern radiotherapy technology, severe late urinary and intestinal toxic effects are rare and do not seem to increase compared with prostate-only radiotherapy.

OLIGOPELVIS GETUG P07, a Multicenter Phase II Trial of Combined High-dose Salvage Radiotherapy and Hormone Therapy in Oligorecurrent Pelvic Node Relapses in Prostate Cancer

BACKGROUND

Oligorecurrent pelvic nodal relapse in prostatic cancer is a challenge for regional salvage treatments. Androgen depriving therapies (ADTs) are a mainstay in metastatic prostate cancer, and salvage pelvic radiotherapy may offer long ADT-free intervals for patients harboring regional nodal relapses.

OBJECTIVE

To assess the efficacy of the combination of ADT and salvage radiotherapy in men with oligorecurrent pelvic node relapses of prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed an open-label, phase II trial of combined high-dose intensity-modulated radiotherapy and ADT (6 mo) in oligorecurrent (five or fewer) pelvic node relapses in prostate cancer, detected by fluorocholine positron-emission tomography computed tomography imaging.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was 2-yr progression-free survival defined as two consecutive prostate-specific antigen levels above the level at inclusion and/or clinical evidence of progression as per RECIST 1.1 and/or death from any cause.

RESULTS AND LIMITATIONS

Between August 2014 and July 2016, 67 patients were recruited in 15 centers. Half of the patients had received prior prostatic irradiation. The median age was 67.7 yr. After a median follow-up of 49.4 mo, 2- and 3-yr progression-free survival rates were 81% and 58%, respectively. Median progression-free survival was 45.3 mo. The median biochemical relapse-free survival (BRFS) was 25.9 mo. At 2 and 3 yr, the BRFS rates were 58% and 46%, respectively. Grade 2 + 2-yr genitourinary and gastrointestinal toxicities were 10% and 2%, respectively.

CONCLUSIONS

Combined high-dose salvage pelvic radiotherapy and ADT appeared to prolong tumor control in oligorecurrent pelvic node relapses in prostate cancer with limited toxicity. After 3 yr, nearly half of patients were in complete remission. Our study showed initial evidence of benefit, but a randomized trial is required to confirm this result.

PATIENT SUMMARY

In this report, we looked at the outcomes of combined high-dose salvage pelvic radiotherapy and 6-mo-long hormone therapy in oligorecurrent pelvic nodal relapse in prostatic cancer. We found that 46% of patients presenting with oligorecurrent pelvic node relapses in prostate cancer were in complete remission after 3 yr following combined treatment at the cost of limited toxicity.

Ultra hypofractionated extended nodal irradiation using volumetric modulated arc therapy for oligorecurrent pelvic nodal prostate cancer

Prostate cancer (PCa) may recur after primary treatment but no standard of care exists for patients with pelvic nodal relapse. Based on obervational data, Extended Nodal Irradiation (ENI) might be associated with fewer treatment failures than Stereotactic Ablative Radiotherapy (SABR) to the involved node(s) alone. Ultra hypofractionated ENI is yet to be evaluated in this setting, but it could provide a therapeutic advantage if PCa has a low α/β ratio in addition to patient convenience/resource benefits. This volumetric modulated arc therapy (VMAT) planning study developed a class solution for 5-fraction Extended Nodal Irradiation (ENI) plus a simultaneous integrated boost (SIB) to involved node(s). Ten patients with oligorecurrent nodal disease after radical prostatectomy/post-operative prostate bed radiotherapy were selected. Three plans were produced for each dataset to deliver 25 Gy in 5 fractions ENI plus SIBs of 40, 35 and 30 Gy. The biologically effective dose (BED) formula was used to determine the remaining dose in 5 fractions that could be delivered to re-irradiated segments of organs at risk (OARs). Tumour control probability (TCP) and normal tissue complication probability (NTCP) were calculated using the LQ-Poisson Marsden and Lyman-Kutcher-Burman models respectively. Six patients had an OAR positioned within planning target volume node (PTVn), which resulted in reduced target coverage to PTV node in six, five and four instances for 40, 35 and 30 Gy SIB plans respectively. In these instances, only 30 Gy SIB plans had a median PTV coverage >90% (inter-quartile range 90-95). No OAR constraint was exceeded for 30 Gy SIB plans, including where segments of OARs were re-irradiated. Gross tumour volume node (GTVn) median TCP was 95.7% (94.4-96), 90.7% (87.1-91.2) and 78.6% (75.8-81.1) for 40, 35 and 30 Gy SIB plans respectively, where an α/β ratio of 1.5 was assumed. SacralPlex median NTCP was 43.2% (0.7-61.2), 12.1% (0.6-29.7) and 2.5% (0.5-5.1) for 40, 35 and 30 Gy SIB plans respectively. NTCP for Bowel_Small was <0.3% and zero for other OARs for all three plan types. Ultra hypofractionated ENI planning for pelvic nodal relapsed PCa appears feasible with encouraging estimates of nodal TCP and low estimates of NTCP, especially where a low α/β ratio is assumed and a 30 Gy SIB is delivered. This solution should be further evaluated within a clinical trial and compared against SABR to involved node(s) alone.

Oligometastatic prostatic cancer recurrence: role of salvage lymph node dissection (sLND) and radiation therapy-stereotactic body radiation therapy (RT-SBRT)

PURPOSE OF REVIEW

Metastases directed therapy (MDT) is an increasingly utilized modality in patients with oligometastatic prostate cancer (OMPC) recurrence. The purpose of our review is to discuss the recent literature on the safety and oncologic outcomes of this treatment approach.

RECENT FINDINGS

Metastases directed therapy, in particular, stereotactic body radiation therapy (SBRT) and salvage lymph node dissection (sLND), has shown promising efficacy in patients with OMPC. Many case series report favorable outcomes with MDT as compared to hormonal deprivation therapy alone or surveillance. Of the few case series investigating the use of MDT as part of a multimodality approach in castrate-resistant OMPC, more favorable outcomes in comparison to the use of systemic treatment alone are reported.

SUMMARY

With the recent advances in imaging techniques, particularly molecular imaging, management of OMPC has progressed rapidly in the last few years. The feasibility and benefits of MDT in OMPC have been demonstrated in prospective and retrospective series. Further prospective studies investigating the role of MDT to define optimal patient subgroups and management strategies are warranted.

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.

Oligorecurrent Prostate Cancer and Stereotactic Body Radiotherapy: Where Are We Now? A Systematic Review and Meta-analysis of Prospective Studies

CONTEXT

The optimal management of oligometastatic prostate cancer (PCa) is still debated.

OBJECTIVE

The purpose of the present systematic review and meta-analysis is to collect the available evidence to date to better define the role of stereotactic body radiotherapy (SBRT) in selected patients with oligorecurrent PCa.

EVIDENCE ACQUISITION

Study methodology complied with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). All prospective studies including PCa patients with nodal and/or bone oligometastases (one to five lesions) were considered eligible. Heterogeneity between study-specific estimates was tested using chi-square statistics and measured with the I2 index. A pooled estimate was obtained by fitting both fixed-effect and DerSimonian and Laird random-effect model.

EVIDENCE SYNTHESIS

Overall, six works (two randomized and the remainder observational) published between 2013 and 2020 were considered eligible. Globally, data from 445 patients were incorporated, of whom 396 were treated with SBRT (329 in observational studies and the remaining 67 in randomized ones). Regarding local progression-free survival (PFS), five studies reported values close to 100%, while one reported a value of 80% in the observation arm. The benefit in terms of biochemical PFS brought by SBRT was evident in all considered studies. Such a difference in cumulative probabilities between the intervention arm and the comparator arm is maintained even 24 mo after the baseline. All studies but one considered toxicity among the endpoints of interest. Most events were classified as either G1 or G2, and the only G ≥ 3 adverse event was reported in one trial.

CONCLUSIONS

SBRT is highly cost effective, safe, and with an almost inexistent toxicity risk that makes it the perfect candidate for the optimal management of PCa oligometastatic patients. However, more solid data and a higher level of evidence are needed to affirm its role in the management of these patients.

PATIENT SUMMARY

In this work, we reviewed available evidence on the use of stereotactic body radiotherapy in treating oligometastatic prostate cancer patients. We found good evidence that radiotherapy brings important benefits in overall treatment efficacy without major side effects.

Radiotherapy treatment volumes for oligorecurrent nodal prostate cancer: a systematic review

BACKGROUND

Radiotherapy is an emerging treatment strategy for nodal oligorecurrent prostate cancer (PCa) patients. However, large heterogeneities exist in the RT regimens used, with series reporting the use of elective nodal radiotherapy (ENRT) strategies and others the delivery of focal treatments to the relapsing nodes with Stereotactic Body Radiotherapy (SBRT). In this systematic review of the literature we compared the oncological outcomes and toxicity of the different RT regimens for nodal oligorecurrent PCa patients, with the aim of defining the optimal RT target volume in this setting.

METHODS

We performed a systemic search on the Pubmed database to identify articles reporting on the use of ENRT or SBRT for oligometastatic PCa with nodal recurrence.

RESULTS

Twenty-two articles were analyzed, including four prospective phase II trials (3 with SBRT and 1 with ENRT). Focal SBRT, delivered with an involved node, involved site, and involved field modality, was the most commonly used strategy with 2-year progression-free survival (PFS) rates ranging from 16 to 58% and a very low toxicity profile. Improved PFS rates were observed with ENRT strategies (52-80% at 3 years) compared to focal SBRT, despite a slightly higher toxicity rate. One ongoing randomized phase II trial is comparing both modalities in patients with nodal oligorecurrent PCa.

CONCLUSIONS

With a large variability in patterns of practice, the optimal RT strategy remains to be determined in the setting of nodal oligorecurrent PCa. Ongoing randomized trials and advances in translational research will help to shed light on the best management for these patients. .

How to improve clinical research in a department of radiation oncology

INTRODUCTION

Radiation therapy is a core modality for cancer treatment. Around 40% of cancer cures include the use of radiotherapy, either as a single strategy or combined with other treatments. In the past decade, substantial technical advances and novel insights into radiobiological properties have considerably improved patients' outcomes. This study overviewed the landscape of clinical research at our radiotherapy department.

METHODS

We surveyed our institutional database of clinical trials to collect information for completed or ongoing radiation therapy clinical trials, from 2005 to December 2017 at the Lucien Neuwirth cancer institute.

RESULTS

A total of 31 clinical trials were undertaken during the study period, of which 4 studies (12.9%) were industry-sponsored and 3 studies (9.7%) were launched by our radiotherapy unit. The vast majority of clinical trials (83.9%) were dedicated to unique organ localization, especially urological cancer (prostate or bladder) (42%). We also observed a shift towards more phase II trials during the study period as well as a special focus on elderly population. Over the last decade, the number of included patients increased by a 5.3 fold input, with 135 inclusions before 2011 and 720 inclusions after 2011.

DISCUSSION

This study provided an observational and comprehensive analysis of radiotherapy research. From a monocentric point-of-view, these results reflected the on-going progress of worldwide radiotherapy research. Based on a 13-years' experience, this study aimed at highlighting essential cues to ensure efficient and perennial research.

Salvage low-dose-rate brachytherapy for local recurrences after prostatectomy and adjuvant or salvage external beam irradiation: Feasibility study on five patients and literature review

PURPOSE

To assess the feasibility and tumor outcome of re-irradiation with low-dose-rate brachytherapy for macroscopic local recurrences after radical prostatectomy (RP) followed by adjuvant or salvage external beam radiation therapy (EBRT).

METHODS AND MATERIALS

Between 2011 and 2018, five men with histologically proven local failure within the prostate (4) or seminal vesicle bed (1) after RP and adjuvant or salvage EBRT (median dose: 67.5 Gy) underwent a salvage brachytherapy (S-BT). The median delay after EBRT was 86 months (range 75-234). Two patients were castration-resistant at the time of S-BT. The gross tumor volume was defined on a multiparametric MRI and transrectal US imaging. Echo-guided transperineal implants of Iodine-125 seeds were optimized with a per-operative dosimetry and delivered with the seed-selectron.

RESULTS

A high conformity was achieved with a high dose to the CTV (D_95% > 145 Gy in all but one) and very low dose to the rectum, urethra, and bladder. With a median followup of 21 months, all but one patient experienced nodes and/or bone metastases. Local control was achieved in 3/4 of evaluable patients (local failure distant to the treated volume in one). To date, no Grade 2 or more late toxicities were observed.

CONCLUSION

For selected patients, focal local recurrence brachytherapy after PR and EBRT appears technically feasible and safe, but the efficacy remains uncertain as the majority of patients quickly relapsed at other sites. Large prospective studies are still required to better select patients who will benefit from this strategy.

Long-term clinical outcomes of salvage pelvic radiation therapy for oligo-recurrent pelvic lymph nodes after definitive external-beam radiation therapy for non-metastatic prostate cancer

Although salvage external-beam radiation therapy (EBRT) is an attractive treatment option for pelvic lymph nodal recurrence (PeNR) in patients with prostate cancer (PCa), limited data are available regarding its long-term efficacy. This study examined the long-term clinical outcomes of patients who underwent salvage pelvic radiation therapy (sPRT) for oligo-recurrent pelvic lymph nodes after definitive EBRT for non-metastatic PCa. Patients who developed PeNR after definitive EBRT and were subsequently treated with sPRT at our institution between November 2007 and December 2015 were retrospectively analyzed. The prescribed dose was 45-50.4 Gy (1.8-2 Gy per fraction) to the upper pelvis, with up to 54-66 Gy (1.8-2 Gy per fraction) for recurrent nodes. Long-term hormonal therapy was used as neoadjuvant and/or adjuvant therapy. The study population consisted of 12 consecutive patients with PeNR after definitive EBRT (median age: 73 years). The median follow-up period was 58.9 months. The 5-year overall survival, PCa-specific survival, biochemical failure-free, clinical failure-free, and castration-resistant PCa-free rates were 82.5, 100.0, 62.3, 81.8, and 81.8%, respectively. No grade 2 or higher sPRT-related late toxicities occurred. In conclusion, more than half of the study patients treated with sPRT had a long-term disease-free status with acceptable morbidities. Moreover, most of the patients maintained hormonal sensitivity. Therefore, this approach may be a promising treatment method for oligo-recurrent pelvic lymph nodes.

[Oligorecurrent prostate cancer: current management and perspectives]

Oligometastatic prostate cancer (PCa) is an intense area of research thanks to the development of novel PET tracers such as ¹⁸F-choline or ⁶⁸Ga-PSMA. Several retrospective studies in patients with hormone-sensitive oligorecurrent PCa (usually up to 5 metastases with a controlled primary tumor) showed PSA response and a low toxicity profile of metastasis-directed therapies (MDT) such as Stereotactic Body Radiation Therapy (SBRT) or salvage lymph node dissection. More recently, randomized phase 2 studies showed that SBRT can delay the introduction of androgen deprivation, decrease biochemical relapses and increase overall survival. Regarding oligoprogressive metastatic castration-resistant PCa, limited data is however available. Based on these studies the European Association of Urology and the American Society of Radiotherapy EAU now recommend using MDT instead of observation. Several studies are undergoing in France and worldwide in order to confirm the exact role of MDT.

Salvage radiotherapy in patients affected by oligorecurrent pelvic nodal prostate cancer

PURPOSE

Metastasis-directed therapy (MDT) is an investigational treatment option in patients with oligorecurrent prostate cancer (PCa). The aim of this retrospective study is to report oncologic outcome and toxicity of elective nodal radiotherapy (ENRT) in PCa patients affected by pelvic nodal oligorecurrence.

METHODS

41 consecutive patients were treated with salvage radiotherapy. At biochemical recurrence after primary treatment, oligorecurrent disease was detected by positron emission tomography (PET) in 94% of the patients. Image-guided intensity modulated radiation therapy (IMRT) was delivered using tomotherapy. 83% of the patients received androgen deprivation therapy (ADT) in combination with ENRT. Survival analysis was performed with Kaplan-Meier method, log-rank test was used to analyze associations between survival end-points and clinical parameters. Multivariate analysis was performed using Cox proportional hazards regression models. Toxicity was registered according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0.

RESULTS

The median at follow-up was 33.6 months. At 3 years, overall survival (OS), cancer-specific survival (CSS), and biochemical progression-free survival (b-PFS) were 89%, 92%, and 53%, respectively. At univariate analysis, all survival end-points were correlated with the number of positive pelvic lymph nodes at oligorecurrence (≤ 3 vs > 3). Biochemical-PFS was correlated with PSA (p = 0.034) and PSA doubling time (p = 0.004) at oligorecurrence. At multivariate analysis, no independent variable was statistically significant. No patient experienced grade ≥ 2 late toxicity after radiotherapy.

CONCLUSIONS

The number of metastatic lymph nodes and PSA doubling time seems to be important prognostic factors in the pelvic oligorecurrent setting. Salvage radiotherapy combined with short-course ADT might be a valid treatment strategy.

PEACE V - Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): a study protocol for a randomized controlled phase II trial

BACKGROUND

Pelvic nodal recurrences are being increasingly diagnosed with the introduction of new molecular imaging techniques, like choline and PSMA PET-CT, in the restaging of recurrent prostate cancer (PCa). At this moment, there are no specific treatment recommendations for patients with limited nodal recurrences and different locoregional treatment approaches are currently being used, mostly by means of metastasis-directed therapies (MDT): salvage lymph node dissection (sLND) or stereotactic body radiotherapy (SBRT). Since the majority of patients treated with MDT relapse within 2 years in adjacent lymph node regions, with an estimated median time to progression of 12-18 months, combining MDT with whole pelvic radiotherapy (WPRT) may improve oncological outcomes in these patients. The aim of this prospective multicentre randomized controlled phase II trial is to assess the impact of the addition of WPRT to MDT and short-term androgen deprivation therapy (ADT) on metastasis-free survival (MFS) in the setting of oligorecurrent pelvic nodal recurrence.

METHODS & DESIGN

Patients diagnosed with PET-detected pelvic nodal oligorecurrence (≤5 nodes) following radical local treatment for PCa, will be randomized in a 1:1 ratio between arm A: MDT and 6 months of ADT, or arm B: WPRT added to MDT and 6 months of ADT. Patients will be stratified by type of PET-tracer (choline, FACBC or PSMA) and by type of MDT (sLND or SBRT). The primary endpoint is MFS and the secondary endpoints include clinical and biochemical progression-free survival (PFS), prostate cancer specific survival, quality of life (QoL), toxicity and time to castration-resistant prostate cancer (CRPC) and to palliative ADT. Estimated study completion: December 31, 2023.

DISCUSSION

This is the first prospective multicentre randomized phase II trial assessing the potential of combined WPRT and MDT as compared to MDT alone on MFS for patients with nodal oligorecurrent PCa.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03569241, registered June 14, 2018, ; Identifier on Swiss National Clinical Trials Portal (SNCTP): SNCTP000002947, registered June 14, 2018.

Metastasis-directed Therapy in Treating Nodal Oligorecurrent Prostate Cancer: A Multi-institutional Analysis Comparing the Outcome and Toxicity of Stereotactic Body Radiotherapy and Elective Nodal Radiotherapy

BACKGROUND

Stereotactic body radiotherapy (SBRT) and elective nodal radiotherapy (ENRT) are being investigated as metastasis-directed treatments in oligorecurrent prostate cancer (PC); however, comparative data are still lacking.

OBJECTIVE

To compare outcome and toxicity between both treatments. Primary endpoint was metastasis-free survival, adjusted for selected variables (aMFS).

DESIGN, SETTING, AND PARTICIPANTS

This was a multi-institutional, retrospective analysis of 506 (SBRT: 309, ENRT: 197) patients with hormone-sensitive nodal oligorecurrent PC (five or fewer lymph nodes (LNs; N1/M1a), treated between 2004 and 2017. Median follow-up was 36 mo (interquartile range 23-56).

INTERVENTION

SBRT was defined as a minimum of 5 Gy per fraction to each lesion with a maximum of 10 fractions. ENRT was defined as a minimum dose of 45 Gy in up to 25 fractions to the elective nodes, with or without a simultaneous boost to the suspicious node(s). The choice of radiotherapy (RT) was at the discretion of the treating physician, with treatments being unbalanced over the centers.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

In total, 506 patients from 15 different treatment centers were included. Primary treatment was radical prostatectomy, RT, or their combination. Nodal recurrences were detected by positron emission tomography/computer tomography (97%) or conventional imaging (3%). Descriptive statistics was used to summarize patient characteristics.

RESULTS AND LIMITATIONS

ENRT was associated with fewer nodal recurrences compared with SBRT (p < 0.001). In a multivariable analysis, patients with one LN at recurrence had longer aMFS after ENRT (hazard ratio: 0.50, 95% confidence interval 0.30-0.85, p = 0.009). Late toxicity was higher after ENRT compared with that after SBRT (16% vs. 5%, p < 0.01). Limitations include higher use of hormone therapy in the ENRT cohort and nonstandardized follow-up.

CONCLUSIONS

ENRT reduces the number of nodal recurrences as compared with SBRT, however at higher toxicity. Our findings hypothesize that ENRT should be preferred to SBRT in the treatment of nodal oligorecurrences. This hypothesis needs to be evaluated in a randomized trial.

PATIENT SUMMARY

This study investigated the difference between stereotactic and elective nodal radiotherapy in treating limited nodal metastatic prostate cancer. Nodal relapse was less frequent following elective nodal radiotherapy than following stereotactic body radiotherapy, and thus elective nodal radiotherapy might be the preferred treatment.

11C-Choline PET Guided Salvage Radiation Therapy for Isolated Pelvic and Paraortic Nodal Recurrence of Prostate Cancer After Radical Prostatectomy: Rationale and Early Genitourinary or Gastrointestinal Toxicities

Purpose

To assess gastrointestinal (GI) and genitourinary (GU) adverse events (AEs) of ¹¹C-choline-positron emission tomography (CholPET) guided lymph node (LN) radiation therapy (RT) in patients who experience biochemical failure after radical prostatectomy.

Methods and Materials

From 2013 to 2016, 107 patients experienced biochemical failure of prostate cancer, had CholPET-detected pelvic and/or paraortic LN recurrence, and were referred for RT. Patients received androgen suppression and CholPET guided LN RT (median dose, 45 Gy) with a simultaneous integrated boost to CholPET-avid sites (median dose, 56.25 Gy), all in 25 fractions. RT-naïve patients had the prostatic fossa included in the initial treatment volumes followed by a sequential boost (median dose, 68 Gy). GI and GU AEs were reported per Common Terminology Criteria for Adverse Events (version 4.0) with data gathered retrospectively. Differences in maximum GI and GU AEs at baseline, immediately post-RT, and at early (median, 4 months) and late (median, 14 months) follow-up were assessed.

Results

Median follow-up was 16 months (interquartile range [IQR], 11-25). Median prostate-specific antigen at time of positive CholPET was 2.3 ng/mL (IQR, 1.3-4.8), with a median of 2 (IQR, 1-4) choline-avid LNs per patient. Most recurrences were within the pelvis (53%) or pelvis + paraortic (40%). Baseline rates of grade 1 to 2 GI AEs were 8.4% compared with 51.9% (4.7% grade 2) of patients post-RT (P < .01). These differences resolved by 4-month (12.2%, P = .65) and 14-month AE assessments (9.1%, P = .87). There was no significant change in grade 1 to 2 GU AEs post-RT (64.1%) relative to baseline (56.0%, P = .21), although differences did arise at 4-month (72.2%, P = .01) and 14-month (74.3%, P = .01) AE assessments.

Conclusions

Salvage CholPET guided nodal RT has acceptably low rates of acute GI and GU AEs and no significant detriment in 14-month GI AEs. These data are of value in counseling patients and designing prospective trials evaluating the oncologic efficacy of this treatment strategy.

The role of hormone therapy and chemotherapy in oligometastatic prostate cancer

Oligometastatic disease was proposed by Hellman and Weichselbaum in 1995 as an intermediate tumour state between localised lesions and widespread metastases, characterised by the limited number and size of metastases in specific organs such as lung, liver, bone or even brain. The oligometastatic state has increasingly been recognised as a unique clinical state during which local ablative treatment can be effective in several types of cancer, including prostate cancer. However, the role of systemic therapy, such as hormone therapy and chemotherapy, is not yet well known. Some promising data for local ablative therapy have emerged, but it remains unclear whether local therapy can eliminate the need for, androgen-deprivation therapy (ADT), or reduce the required duration. In addition, several randomised phase III trials have demonstrated survival benefits from the addition of docetaxel or abiraterone to ADT in patients with metastatic hormone-sensitive prostate cancer. These findings suggest that such aggressive treatments may improve clinical outcomes for patients with oligometastatic prostate cancer. However, the efficacy of these treatments may depend on the volume of metastases, with higher efficacy for high-volume disease. Therefore, further investigation including stratification by disease volume is warranted. This review will discuss the current evidence and controversies surrounding the role of systemic therapy in patients with oligometastatic prostate cancer.