Postoperative elective pelvic nodal irradiation compared to prostate bed irradiation in locally advanced prostate cancer – a retrospective analysis of dose-escalated patients

Abstract

Background It is uncertain if whole-pelvic irradiation (WPRT) in addition to dose-escalated prostate bed irradiation (PBRT) improves biochemical progression-free survival (bPFS) after prostatectomy for locally advanced tumors. This study was initiated to analyze if WPRT is associated with bPFS in a patient cohort with dose-escalated (> 70 Gy) PBRT. Methods Patients with locally advanced, node-negative prostate carcinoma who had PBRT with or without WPRT after prostatectomy between 2009 and 2017 were retrospectively analyzed. A simultaneous integrated boost with equivalent-doses-in-2-Gy-fractions (EQD-2) of 79.29 Gy or 71.43 Gy to the prostate bed was applied in patients with margin-positive (or detectable) and margin-negative/undetectable tumors, respectively. WPRT (44 Gy) was offered to patients at an increased risk of lymph node metastases. Results Forty-three patients with PBRT/WPRT and 77 with PBRT-only were identified. Baseline imbalances included shorter surgery-radiotherapy intervals (S-RT-Intervals) and fewer resected lymph nodes in the WPRT group. WPRT was significantly associated with better bPFS in univariate ( p = 0.032) and multivariate models (HR = 0.484, p = 0.015). Subgroup analysis indicated a benefit of WPRT ( p = 0.029) in patients treated with rising PSA values who mostly had negative margins (74.1%); WPRT was not associated with a longer bPFS in the postoperative setting with almost exclusively positive margins (96.8%). Conclusion We observed a longer bPFS after WPRT compared to PBRT in patients with locally advanced prostate carcinoma who underwent dose-escalated radiotherapy. In subset analyses, the association was only observed in patients with rising PSA values but not in patients with non-salvage postoperative radiotherapy for positive margins. Electronic supplementary material The online version of this article (10.1186/s13014-019-1301-5) contains supplementary material, which is available to authorized users.

Efficacy and Toxicity of Whole Pelvic Radiotherapy Versus Prostate-Only Radiotherapy in Localized Prostate Cancer: A Systematic Review and Meta-Analysis

“…There has been considerable controversy over whether to choose whole pelvic radiotherapy (WPRT) or prostate-only radiotherapy (PORT) for localized prostate cancer (37). This meta-analysis included six randomized controlled studies (RCTs) (7)(8)(9)(10)(11)(12) and ten cohort studies (CRS) (23)(24)(25)(26)(27)(28)(29)(30)(31)(32). Of the 16 studies, 9 studies did not perform radical prostatectomy (non-RP), and the patients of the other 7 studies received radical prostatectomy (RP).…”

“…A total of 4,680 publications and 52 registered clinical studies were identified from the literature search, and 16 studies that met the eligibility criteria were finally selected, including 6 randomized controlled trials (RCTs) (7)(8)(9)(10)(11)(12) and 10 cohort studies (CRS) (23)(24)(25)(26)(27)(28)(29)(30)(31)(32). Four studies that met the inclusion criteria were excluded because of no hazard ratio available for survival (33)(34)(35)(36).…”

“…Six studies (9,10,26,(29)(30)(31) with a total of 3,795 patients examined BFFS at 5 years. The forest plot (Figure 2A) indicated that for the patients did not undergo prostatectomy, WPRT was associated with superior BFFS relative to PORT (HR 0.23, CI 0.10-0.52, p < 0.001).…”