Treatment-related toxicity using prostate bed versus prostate bed and pelvic lymph node radiation therapy following radical prostatectomy: A national population-based study.

Purpose There is debate about the effectiveness and toxicity of pelvic lymph node (PLN) irradiation in addition to prostate bed radiotherapy when used to treat disease recurrence following radical prostatectomy. We compared toxicity from radiation therapy (RT) to the prostate bed and pelvic lymph nodes (PBPLN-RT) with prostatebed only radiation therapy (PBO-RT) following radical prostatectomy. Methods and Materials Patients with prostate cancer who underwent post-prostatectomy RT between 2010 and 2016 were identified by using the National Prostate Cancer Audit (NPCA) database. Follow-up data was available up to December 31, 2018. Validated outcome measures, based on a framework of procedural and diagnostic codes, were used to capture ≥Grade 2 gastrointestinal (GI) and genitourinary (GU) toxicity. An adjusted competing-risks regression analysis estimated subdistribution hazard ratios (sHR). A sHR > 1 indicated a higher incidence of toxicity with PBPLN-RT than with PBO-RT. Results 5-year cumulative incidences in the PBO-RT (n = 5,087) and PBPLNRT (n = 593) groups was 18.2% and 15.9% for GI toxicity, respectively. For GU toxicity it was 19.1% and 20.7%, respectively. There was no evidence of difference in GI or GU toxicity after adjustment between PBO-RT and PBPLN-RT (GI: adjusted sHR, 0.90, 95% CI, 0.67-1.19; P = 0.45); (GU: adjusted sHR, 1.19, 95% CI, 0.99-1.44; P = 0.09). Conclusions This national population-based study found that including PLNs in the radiation field following radical prostatectomy is not associated with a significant increase in rates of ≥Grade 2 GI or GU toxicity at 5 years.

Clinical and translational radiation oncology. 2023 Apr 11*** epublish ***

Arunan Sujenthiran, Matthew G Parry, Joanna Dodkins, Julie Nossiter, Melanie Morris, Brendan Berry, Arjun Nathan, Paul Cathcart, Noel W Clarke, Heather Payne, Jan van der Meulen, Ajay Aggarwal

Clinical Effectiveness Unit, Royal College of Surgeons of England, UK., Department of Health Services Research & Policy, LHSTM, UK., Department of Urology, Guy's & St Thomas' NHS Foundation Trust, UK., Department of Urology, The Christie & Salford Royal NHS Foundation Trusts, UK., Department of Oncology, University College London Hospitals, London, UK.