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

Purpose: 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.

Methods And Materials: 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.

Results: 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.

Conclusions: 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.