Salvage Radiotherapy for Macroscopic Local Recurrence Following Radical Prostatectomy

Abstract

IntroductionSalvage radiotherapy is the only curative treatment for biochemical progression after radical prostatectomy. Macroscopic recurrence may be found in the prostatic bed. The purpose of our study is to evaluate the effectiveness of salvage radiotherapy of the prostate bed with a boost to the area of the macroscopic recurrence.Material and MethodsFrom January 2005 to January 2020, 89 patients with macroscopic recurrence in the prostatectomy bed were treated with salvage radiotherapy +/- hormone therapy. The average PSA level prior to radiotherapy was 1.1 ng/mL (SD: 1.6). At the time of biochemical progression, 96% of the patients had a MRI that revealed the macroscopic recurrence, and 58% had an additional choline PET scan. 67.4% of the patients got a boost to the macroscopic nodule, while 32.5% of the patients only underwent radiotherapy of the prostate bed without a boost. The median total dose of radiotherapy was 70 Gy (Min.: 60 – Max.: 74). The most commonly-used regimen was radiotherapy of the prostatectomy bed with a concomitant boost. 48% of the patients were concomitantly treated with hormone therapy.ResultsAfter a median follow-up of 53.7 months, 77 patients were alive and 12 had died, of which 4 following metastatic progression. The 5-year and 8-year survival rates (CI95%) are, respectively, 90.2% (78.9-95.6%) and 69.8% (46.4-84.4%). The 5-year biochemical progression-free survival rate (CI95%) is 50.8% (36.7-63.3). Metastatic recurrence occurred in 11.2% of the patients. We did not find any statistically significant impact from the various known prognostic factors for biochemical progression-free survival. No toxicity with a grade of > or = to 3 was found.ConclusionsOur series is one of the largest published to date. Salvage radiotherapy has its place in the management of patients with biochemical progression with local recurrence in the prostate bed, with an acceptable toxicity profile. The interest of the boost is to be evaluated in prospective trials.

Dose-Escalated Salvage Radiotherapy for Macroscopic Local Recurrence of Prostate Cancer in the Prostate-Specific Membrane Antigen Positron Emission Tomography Era

“…Up-to-date, prospective randomized trials assessing salvage radiotherapy for macroscopic prostate cancer recurrence are not yet available, while only a few retrospective studies address this topic (Table 4). Our outcome results compare favorably to published analyses: with a five-year biochemical progression-free survival rate of 89.1%, biochemical control is higher here than in the studies of Shelan et al, Bruni et al, Zili et al, and Zaine et al [10,[12][13][14]. A direct comparison of retrospective data is difficult due to the heterogeneity in patient characteristics and treatment parameters.…”

“…Pre-SRT PSA value might be a surrogate marker for disease spread, and thorough staging with modern imaging naturally seems as though it would be important for discriminating local from advanced disease. Several studies on salvage radiotherapy for macroscopic prostate cancer recurrence did not employ, or only partly employed, PSMA PET/CT as pre-SRT staging [10][11][12][13][14][15][16][17]. Therefore, potential understaging in the mentioned trials may explain the difference in biochemical control compared with our study.…”

“…Despite being an important clinical scenario, no consensus for dose-escalated radiotherapy for macroscopic recurrence in the prostate bed exists [11]. Moreover, as most retrospective studies for macroscopic prostate cancer recurrence have used conventional imaging or predominantly choline PET/CT imaging as a pre-SRT staging method, data from PSMA PET/CT-based SRT for macroscopic relapse are still limited at present [10][11][12][13][14][15][16][17].…”

Targeting Local Recurrence After Surgery With MRI Imaging for Prostate Cancer in the Setting of Salvage Radiation Therapy

“…Toxicity was not increased and local relapse-free survival was 100%. A concomitant integrated boost is also feasible without increasing toxicity ( 56 ). However, the benefit of this boost dose was not demonstrated ( 55 – 57 ).…”

Post-Operative Radiotherapy in Prostate Cancer: Is It Time for a Belt and Braces Approach?

“…Based on these results, dose escalation beyond 66 Gy does not seem to offer any improvement of oncological outcomes, at the cost of increased grade 2 or higher toxicity. Soon, the advent of novel radiotracers may guide further refinement of treatment volumes and dose escalation focused exclusively on the residual disease targets ( 27 , 28 ).…”