Treatment outcomes of postoperative ultra-hypofractionated stereotactic body radiotherapy in prostate cancer

• Published in: Urologic oncology Vol. 41; no. 5; pp. 252.e1 - 252.e8
• Main Authors: Ozyigit, Gokhan, Onal, Cem, Beduk Esen, Caglayan Selenge, Tilki, Burak, Hurmuz, Pervin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2023
• Subjects: Humans; Male; Postoperative; Prostate bed; Prostate cancer; Prostate-Specific Antigen; Prostatic Neoplasms - etiology; Prostatic Neoplasms - radiotherapy; Prostatic Neoplasms - surgery; Radiosurgery - adverse effects; Retrospective Studies; SBRT; Treatment Outcome; Ultra-hypofractionated radiotherapy; Postoperative; Ultra-hypofractionated radiotherapy; Prostate bed; Prostate cancer; SBRT
• ISSN: 1078-1439; 1873-2496
• DOI: 10.1016/j.urolonc.2022.12.001

•Postoperative ultra-fractionated stereotactic body radiation therapy (SBRT) has tolerable acute and late toxicity.•Postoperative ultra-fractionated SBRT has excellent biochemical control rates.•Postoperative SBRT does not increase grade 3 or higher GU toxicity.•Pre- and post-SBRT PSA levels may be a reliable predictor of biochemical response. This study aimed to evaluate the safety and efficacy of ultra-hypofractionated stereotactic body radiation therapy (SBRT) to prostate bed. Sixty-six prostate cancer patients treated with postoperative ultra-hypofractionated SBRT between 2018 and 2020 were retrospectively reviewed. All patients received a total dose of 35 Gy to prostate bed in 5 fractions. Biochemical complete response (BCR), biochemical failure (BF), acute and late toxicities were assessed. After a median follow-up of 24.2 months (range, 6.4–37.2), seven patients (10.6%) developed BF, and the 2-year freedom from BF (FFBF) rate was 88.4%. BCR was observed in 57 patients (86.4%). The 2-year FFBF in patients with pre-SBRT PSA value of <0.2 ng/mL was higher than those with pre-SBRT PSA of ≥0.2 ng/mL (100% vs. 81.4%; P = 0.04). The 2-year FFBF in patients with BCR was significantly higher than in those without BCR (94.5% vs. 58.3%; P < 0.001). In multivariate analysis, pre-SBRT PSA and post-SBRT PSA values were prognostic factors for FFBF (P = 0.009 and P = 0.01, respectively). Nine patients (13.6 %) developed acute and late grade 2 genitourinary (GU) toxicities. There was no acute or late grade ≥3 GU toxicity. Acute and late grade ≥2 gastrointestinal (GI) toxicity was observed in 9 (13.6%) and 2 (3%) patients, respectively. Postoperative ultra-fractionated SBRT showed no severe acute toxicity and late toxicity rates of about 15%, in addition to excellent biochemical control rates. Pre- and post-SBRT PSA levels may be a predictor of BCR in patients receiving post-operative ultra-fractionated SBRT.