Safety of Ultrahypofractionated Pelvic Nodal Irradiation in the Definitive Management of Prostate Cancer: Systematic Review and Meta-analysis

Abstract

Aim: This systematic review and meta-analysis aimed to evaluate the evidence for ultra-hypofractionated pelvic nodal irradiation in prostate cancer patients, with a focus on reported acute and late toxicities. Methods: A comprehensive search was conducted in five electronic databases (PubMed, Scopus, Web of Science, Cochrane Library, Clinicaltrials.gov) from inception until 23 March 2023. Eligible publications included patients with intermediate- and high-risk and node positive prostate cancer who underwent elective or therapeutic ultra-hypofractionated pelvic nodal irradiation. Primary outcomes included the presence of grade ≥2 rates of acute and late gastrointestinal and genitourinary toxicity based on the Common Terminology Criteria for Adverse Events (CTCAE) scale or Radiation Therapy Oncology Group (RTOG) scales. Quality assessment was performed using NIH tools for non-controlled before and after clinical trials, as well as single-arm observational studies. Since all outcomes were categorical variables, proportion was calculated to estimate the effect size and compare the outcomes after the intervention. Results: We identified 16 publications that reported the use of ultra-hypofractionated radiotherapy to treat the pelvis in prostate cancer. Seven publications met our criteria and were included in the meta-analysis, including 417 patients. The median total dose to the pelvic lymph nodes was 25 Gy (range: 25 - 28.5 Gy), with a median of 5 fractions. The prostate received a median dose of 40 Gy (range: 35 to 47.5 Gy). All studies utilized androgen deprivation therapy for a median duration of 18 months. The median follow-up period was 3 years (range: 0.5-5.6 years). The rates of acute grade ≥2 gastrointestinal and genitourinary toxicity were 8% (CI 95%: 1% to 15%) and 29% (CI 95%: 18% to 41%), respectively. For late grade ≥2 gastrointestinal and genitourinary toxicity, the rates were 13% (CI 95%: 5% to 21%) and 29% (CI 95%: 17% to 42%), respectively. Conclusion: Ultra-hypofractionated pelvic nodal irradiation appears to be a safe approach in terms of acute and late genitourinary and gastrointestinal toxicity.