Stereotactic ablative radiotherapy (SABR) is growingly accepted for the treatment of localized prostate cancer with recent randomized trials showing non-inferiority compared to conventional or moderately hypofractionated radiotherapy. The natural history of prostate cancer necessitates extended surveillance for recurrence; however, there are few prospective studies reporting long-term outcomes.
This study included patients with low and intermediate risk localized prostate cancer from three Canadian clinical trials enrolled from 2006-2013. All patients received SABR to the prostate consisting of 35-40 Gy in 5 fractions over 11-29 days. PSA, distant metastasis, and vital status were prospectively recorded. Occurrence of second malignancy after treatment was assessed by chart review and classified using modified Cahan's criteria.
267 patients were included. Median follow up was 10.3 years (IQR 7.8 - 12.7). 10-year BF (95% CI) was 7.7% (3.9-11.5). 10-year OS, PCSS, and FFM were 84.1% (79.3 - 89.1%), 99.2% (98.1 - 100), and 98.8% (97.5-100), respectively. 27/267 (10.1%) patients experienced a SM, with 6/27 patients (22.2%) classified as having a SM likely (n=3) or possibly (n=3) related to prior radiotherapy. 10-year freedom from SM was 89.2%.
SABR shows excellent long-term disease control for low and intermediate risk localized prostate cancer. Patients treated for prostate cancer have a moderate risk of second malignancy, consistent with background rates for the population.
International journal of radiation oncology, biology, physics. 2024 Sep 16 [Epub ahead of print]
Thomas A C Kennedy, Wee Loon Ong, Harvey Quon, Patrick Cheung, William Chu, Hans Chung, Danny Vesprini, Dilip Panjwani, Yasir Alayed, Geordi Pang, Renee Korol, Liying Zhang, Alexandre Mamedov, Andrea Deabreu, Andrew Loblaw
Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada., Alfred Health, Radiation Oncology, Monash University, Melbourne, Victoria, Australia., Tom Baker Cancer Centre, Calgary, Alberta, Canada., BC Cancer, Abbotsford, British Colombia, Canada., Radiation Oncology Unit, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia., Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada., Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada. Electronic address: .