Use of stereotactic body radiation therapy for oligometastatic recurrent prostate cancer: A systematic review

Abstract

The purpose of this study is to evaluate the effectiveness and safety of stereotactic body radiation therapy (SBRT) in the management of oligometastatic recurrent prostate cancer (PCa) by means of a systematic review. Six databases were searched (CENTRAL, Embase, LILACS, PubMed, Scopus and Web of Science). Additionally, hand-searching and grey literature search were performed. The main outcomes were progression-free survival (PFS) and toxicity rates. Androgen deprivation therapy-free survival (ADT-FS), local control, pattern of recurrence, cancer-specific survival and overall survival were also assessed. Risk of bias and quality of evidence were judged with the aid of specific tools. Fourteen studies were included, involving 661 patients and 899 lesions (561 nodal, 336 bone, 2 liver). Median PFS and ADT-FS were around 1 to 3 years. Local control rates varied from 82 to 100% among researches with low risk of bias. Acute and late grade 2 toxicity was observed in 2.4% and 1.1% of the patients, respectively. One case of acute and two cases of late grade 3 toxicity were registered. Only one randomized study addresses this topic. Although it does not meet all the eligibility criteria, it is useful for the discussion. A quantitative analysis was not possible, nor were subgroup analyses, due to the significant heterogeneity of the interventions and outcomes reported. Longer follow-up period is required. SBRT seems to be a safe approach to metastatic lesions that might provide disease control and defer androgen deprivation therapy (ADT). Local control is better when higher radiation doses are employed.

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

“…In prostate cancer, the argument of aggressive local treatments is supported by the recent finding that indolent metastatic lesions have the potential to transform and become aggressive foci of accelerated metastases ( 81 , 82 ). A recent systematic review summarized the use of SBRT for PET/CT proven oligometastatic prostate cancer ( 83 ). This study demonstrated excellent local outcomes, with no local recurrences when RT dose exceeded a biologically effective dose (BED) of >108 Gy (α/β = 3 Gy).…”

Survey of current practices from an international task force for gynecological stereotactic ablative radiotherapy

“…Several non-randomized studies and systematic reviews have shown a potential benefit of SABR treatment for oligometastatic disease in other solid tumours, such as breast, colorectal, lung and prostate. These studies have generally demonstrated that SABR for oligometastases yields high local control and may confer improved disease survival [25][26][27][28]. SABR-COMET was a phase II randomization between SABR and standard of care palliative radiation.…”

A narrative review of oligometastatic prostate cancer—an evolving paradigm

“…The heterogeneous dose/fractionation schedules, inconsistent use of ADT, widespread dependence on conventional imaging and short follow-up complicate interpretation. This notwithstanding, a systematic review of 661 patients reported median PFS and ADT-free survival of between 1-3 years, excellent local control of 100% for tumours receiving a BED >108 Gy (α/β =3), and importantly, only 1 patient reported grade 3 acute toxicity (87). Data supporting SBRT in metachronous oligometastatic disease Accordant results were achieved in the POPSTAR trial, which evaluated the role of SBRT (20 Gy in 1 fraction) to up to 3 bone-only (n=20), node-only (n=12) or both (n=1) oligometastases (83).…”