Exploring All Avenues for Radiotherapy in Oligorecurrent Prostate Cancer Disease Limited to Lymph Nodes: A Systematic Review of the Role of Stereotactic Body Radiotherapy

Abstract

ContextStereotactic body radiotherapy (SBRT) is emerging as a treatment option in patients affected by oligorecurrent prostate cancer disease limited to lymph nodes, a subgroup of patients who would otherwise be treated only with androgen deprivation therapy (ADT). ObjectiveTo perform a systematic review of SBRT for oligorecurrent prostate cancer limited to lymph nodes. Evidence acquisitionWe performed a systematic review of PubMed/Medline in October 2016 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA). We searched for studies reporting on biochemical or clinical progression and/or toxicity or complications of SBRT. Reports were excluded if these end points could not be ascertained or separately analyzed, or if insufficient details were provided. Evidence of synthesisA total of 363 patients from nine studies were collected. Of these patients, 211 were treated with SBRT for a total of 270 lymph nodes. With an alpha–beta ratio of 3 Gy, the biologically effective dose in fractionated SBRT was >100 Gy in all studies (range, 88–216 Gy). With a median follow-up of 19.23 mo, local control was achieved in 98.1% of patients. Median progression-free survival (defined as biochemical and/or radiological progression) was 22.5 mo (range, 11–30 mo). Information about ADT during SBRT was available in 281 patients, of whom 114 (40.5%) were on ADT during SBRT, and the duration of hormone therapy ranged from 1 to 17.5 mo. Median ADT-free survival was 32.8 mo (range, 25–44 mo). About toxicity, Common Terminology Criteria for Adverse Events toxicity scale was most used. Acute and/or late grade ≥2 toxicity was reported in only 5.6% of patients, and no patient developed grade 4 toxicity. ConclusionsSBRT seems to be promising in lymph node oligorecurrent prostate cancer, although there is a weak level of evidence to support such investigational treatment, which is currently based on retrospective studies of single-institution or pooled experiences. ADT-free survival is an interesting end point, which needs to be investigated. Patient summaryWe performed a systematic review to assess outcomes and toxicity of stereotactic body radiotherapy (SBRT) for patients affected by oligorecurrent prostate cancer limited to lymph nodes. We concluded that SBRT is a promising therapy in this setting, but it needs to be validated in randomized controlled trials.