Meta-analysis of Elective Pelvic Nodal Irradiation Using Moderate Hypofractionation for High-Risk Prostate Cancer

Abstract

Despite several advances in planning and delivery of radiation therapy (RT) for prostate cancer, the role of elective pelvic nodal irradiation (EPNI) remains controversial for high-risk disease. We performed a meta-analysis to evaluate the outcomes of patients treated with moderate hypofractionated RT (MHF-RT) with EPNI using modern RT techniques. Eligible studies were identified on MEDLINE, Embase, the Cochrane Library, and proceedings of annual meetings through October 2021. We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) and MOOSE (Meta-analyses of Observational Studies in Epidemiology) guidelines. A metaregression analysis was performed to assess a possible correlation between selected variables and outcomes. A P value <.05 was considered significant. Eighteen studies with a total of 1745 patients (median follow-up, 61 months) treated with EPNI using MHF-RT were included. The biochemical relapse-free survival at 5, 7, and 10 years was 90% (95% confidence interval [CI], 88%-94%), 83% (95% CI, 78%-91%), and 78% (95% CI, 68%-88%). The 5-year prostate cancer-specific survival, disease-free survival, distant metastases-free survival, and overall survival were 98% (95% CI, 97%-99%), 88.7% (95% CI, 85%-93%), 91.2% (95% CI, 88%-92%), and 93% (95% CI, 90%-96%), respectively. The rates of local, pelvic, and distant recurrence were 0.38% (95% CI, 0%-2%), 0.13% (95% CI, 0%-1.5%), and 7.35% (95% CI, 2%-12%), respectively. The rate of late grade ≥2 gastrointestinal and genitourinary toxic effects were 6.7% (95% CI, 4%-9%) and 11.3% (95% CI, 7.6%-15%), with heterogeneity, but with rare cases of grade 3 to 5 toxic effects. EPNI with concomitant MHF-RT provides satisfactory biochemical relapse-free survival in long-term follow-up, with low rates of genitourinary and gastrointestinal severe toxic effects and minimal pelvic and local failure.