Dose escalation for prostate stereotactic ablative radiotherapy (SABR): Late outcomes from two prospective clinical trials

• Published in: Radiotherapy and oncology 2018-05, Vol.127 (2), p.213-218
• Main Authors: Alayed, Yasir, Cheung, Patrick, Pang, Geordi, Mamedov, Alexandre, D'Alimonte, Laura, Deabreu, Andrea, Commisso, Kristina, Commisso, Angela, Zhang, Liang, Quon, Harvey C., Musunuru, Hima Bindu, Helou, Joelle, Loblaw, D. Andrew
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Dose Fractionation, Radiation; Dose-escalation; Humans; Male; Middle Aged; Prospective Studies; Prostate cancer; Prostate-Specific Antigen - metabolism; Prostatic Neoplasms - blood; Prostatic Neoplasms - radiotherapy; PSA; Radiosurgery - methods; Radiotherapy Dosage; Salvage Therapy - methods; Stereotactic body radiotherapy; Treatment Outcome
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2018.03.005

Optimal prostate SABR dose-fractionation is unknown. This study compares long-term outcomes from two prospective trials. Study1 patients had low-risk PCa and received 35 Gy/5. Study2 patients had low/intermediate-risk PCa and received 40 Gy/5. Biochemical failure (BF) was defined as nadir + 2. 114 patients were included (study1, n = 84; study2, n = 30). Median follow-up was 9.6 years and 6.9 years. Median nPSA was 0.4 and 0.1 ng/ml. Nine patients had BF (8 in study1, 1 in study2); two were managed with ADT and four had local salvage. The BF rate was 2.5% and 12.8% at 5 and 10 years for study1 and 3.3% at 5 years for study 2. BF probability was 0% if PSA