Ten Year Results of Extensive Nodal Radiotherapy and Moderately Hypofractionated Simultaneous Integrated Boost in Unfavorable Intermediate-, High-, and Very High-Risk Prostate Cancer

Nadia Gisella Di Muzio; Chiara Lucrezia Deantoni; Chiara Brombin; Claudio Fiorino; Cesare Cozzarini; Flavia Zerbetto; Paola Mangili; Roberta Tummineri; Italo Dell'Oca; Sara Broggi; Marcella Pasetti; Anna Chiara; Paola Maria Vittoria Rancoita; Antonella Del Vecchio; Mariaclelia Stefania Di Serio; Andrei Fodor

doi:10.3390/cancers13194970

Ten Year Results of Extensive Nodal Radiotherapy and Moderately Hypofractionated Simultaneous Integrated Boost in Unfavorable Intermediate-, High-, and Very High-Risk Prostate Cancer

Cancers (Basel). 2021 Oct 3;13(19):4970. doi: 10.3390/cancers13194970.

Authors

Nadia Gisella Di Muzio^{1

2}, Chiara Lucrezia Deantoni¹, Chiara Brombin^{2

3}, Claudio Fiorino^{2

4}, Cesare Cozzarini¹, Flavia Zerbetto¹, Paola Mangili⁴, Roberta Tummineri¹, Italo Dell'Oca¹, Sara Broggi⁴, Marcella Pasetti¹, Anna Chiara¹, Paola Maria Vittoria Rancoita^{2

3}, Antonella Del Vecchio⁴, Mariaclelia Stefania Di Serio^{2

3}, Andrei Fodor¹

Affiliations

¹ Department of Radiotherapy, IRCCS San Raffaele Scientific Institute, 60 Olgettina Street, 20132 Milan, Italy.
² Vita-Salute San Raffaele University, 20132 Milan, Italy.
³ University Center for Statistics in the Biomedical Sciences, Vita-Salute San Raffaele University, 58 Olgettina Street, 20132 Milan, Italy.
⁴ Medical Physics, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy.

Abstract

Aims: To report 10-year outcomes of WPRT and HD moderately hypofractionated SIB to the prostate in UIR, HR, and VHR PCa.

Methods: From 11/2005 to 12/2015, 224 UIR, HR, and VHR PCa patients underwent WPRT at 51.8 Gy/28 fractions and SIB at 74.2 Gy (EQD2 88 Gy) to the prostate. Androgen deprivation therapy (ADT) was prescribed in up to 86.2% of patients.

Results: Median follow-up was 96.3 months (IQR: 71-124.7). Median age was 75 years (IQR: 71.3-78.1). At last follow up, G3 GI-GU toxicity was 3.1% and 8%, respectively. Ten-year biochemical relapse-free survival (bRFS) was 79.8% (95% CI: 72.3-88.1%), disease-free survival (DFS) 87.8% (95% CI: 81.7-94.3%), overall survival (OS) 65.7% (95% CI: 58.2-74.1%), and prostate cancer-specific survival (PCSS) 94.9% (95% CI: 91.0-99.0%). Only two patients presented local relapse. At univariate analysis, VHR vs. UIR was found to be a significant risk factor for biochemical relapse (HR: 2.8, 95% CI: 1.17-6.67, p = 0.021). After model selection, only Gleason Score ≥ 8 emerged as a significant factor for biochemical relapse (HR = 2.3, 95% CI: 1.12-4.9, p = 0.023). Previous TURP (HR = 3.5, 95% CI: 1.62-7.54, p = 0.001) and acute toxicity ≥ G2 (HR = 3.1, 95% CI = 1.45-6.52, p = 0.003) were significant risk factors for GU toxicity ≥ G3. Hypertension was a significant factor for GI toxicity ≥ G3 (HR = 3.63, 95% CI: 1.06-12.46, p = 0.041). ADT (HR = 0.31, 95% CI: 0.12-0.8, p = 0.015) and iPsa (HR = 0.37, 95% CI: 0.16-0.83, p = 0.0164) played a protective role.

Conclusions: WPRT and HD SIB to the prostate combined with long-term ADT, in HR PCa, determine good outcomes with acceptable toxicity.

Keywords: ADT and radiotherapy in prostate cancer; moderately hypofractionated radiotherapy; pelvic radiotherapy in prostate cancer; prostate cancer radiotherapy boost; radiotherapy in high-risk prostate cancer.