Toxicity profile and Patient-Reported outcomes following salvage Stereotactic Ablative Radiation Therapy to the prostate Bed: The POPART multicentric prospective study

Federica Ferrario; Ciro Franzese; Valeria Faccenda; Suela Vukcaj; Maria Belmonte; Raffaella Lucchini; Davide Baldaccini; Marco Badalamenti; Stefano Andreoli; Denis Panizza; Alessandro Magli; Marta Scorsetti; Stefano Arcangeli

doi:10.1016/j.ctro.2023.100704

Toxicity profile and Patient-Reported outcomes following salvage Stereotactic Ablative Radiation Therapy to the prostate Bed: The POPART multicentric prospective study

Clin Transl Radiat Oncol. 2023 Nov 25:44:100704. doi: 10.1016/j.ctro.2023.100704. eCollection 2024 Jan.

Authors

Federica Ferrario^{1

2}, Ciro Franzese^{3

4}, Valeria Faccenda⁵, Suela Vukcaj⁶, Maria Belmonte^{1

2}, Raffaella Lucchini^{1

2}, Davide Baldaccini⁴, Marco Badalamenti⁴, Stefano Andreoli⁷, Denis Panizza^{1

5}, Alessandro Magli⁸, Marta Scorsetti^{3

4}, Stefano Arcangeli^{1

2}

Affiliations

¹ School of Medicine and Surgery, University of Milan Bicocca, 20126 Milan, Italy.
² Department of Radiation Oncology, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy.
³ Department of Biomedical Sciences, Humanitas University, 20090 Pieve Emanuele (MI), Italy.
⁴ Radiotherapy and Radiosurgery Department, IRCCS Humanitas Research Hospital, 20089 Rozzano (MI), Italy.
⁵ Department of Medical Physics, Fondazione IRCCS San Gerardo dei Tintori, 20900 Monza, Italy.
⁶ Department of Radiation Oncology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy.
⁷ Department of Medical Physics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy.
⁸ Department of Radiation Oncology, AULSS 1 Dolomiti, 32100 Belluno, Italy.

Abstract

Background: While SBRT to the prostate has become a valuable option as a radical treatment, limited data support its use in the postoperative setting. Here, we report the updated results of the multicentric Post-Prostatectomy Ablative Radiation Therapy (POPART) trial, investigating possible predictors of toxicities and patient-reported outcomes.

Methods: Patients with PSA levels between 0.1-2.0 ng/mL after radical prostatectomy received Linac-based SBRT to the prostate bed in five fractions every other day for a total dose of 32.5 Gy (EQD2_1.5 = 74.3 Gy). Late toxicity was assessed using CTCAE v.5 scale, while EPIC-CP, ICIQ-SF, IIEF 5 questionnaires and PSA levels measured quality of life and biochemical control. Pre- and post-treatment scores were compared using a paired t-test, with MID established at > 0.5 pooled SD from the baseline. A logistic regression analysis was performed to evaluate potential associations between specific patient/tumor/treatment factors and outcome deterioration.

Results: From April 2021 to April 2023 a total of 50 pts were enrolled and treated. Median follow-up was 12.2 (3-27) months. No late ≥ G2 GI or GU toxicity was registered. Late G1 urinary and rectal toxicities occurred in 46 % and 4 % of patients, respectively. Among 47 patients completing all EPIC-CP domains, four (9 %) showed worsened QoL, and eleven (26 %) developed erectile dysfunction correlating with PTV D2% (P = 0.032). At Multivariate analysis bladder wall D10cc independently correlated with late G1 GU toxicity (P = 0.034). Median post-treatment PSA nadir was 0.04 ng/mL (0.00 - 0.84). At the last follow-up, six patients presented with biochemical failure, including two nodal relapses.

Conclusions: Our findings show that post-prostatectomy SBRT did not result in increased toxicity nor a significant decline in QoL measures, thus showing that it can be safely extended to the postoperative setting. Long-term follow-up and randomized comparisons with different RT schedules are needed to validate this approach.

Keywords: Postoperative setting; Prostate cancer; SBRT; Salvage RT.