To compare the urinary and gastrointestinal toxicity with or without the inclusion of pelvic nodal regions in patients treated with extreme hypofractionated stereotactic radiotherapy (SBRT) for prostate cancer.
Patients treated with definitive SBRT for non-metastatic adenocarcinoma prostate were identified from prospectively maintained institutional database, and details of radiotherapy volume, dose, acute and late adverse effects were analyzed. Symptoms of acute (within 90 days of completing SBRT) and late gastrointestinal and urinary toxicities were graded using CTCAE version 5.0. Each symptom was scored according to the worst reported grading during treatment and follow-up period. Cumulative toxicity rates between prostate-only SBRT (PO-SBRT) and whole pelvic SBRT (WP-SBRT) were compared using chi-square test.
Total 220 patients were analyzed (PO-SBRT=118, WP-SBRT=102), with a median follow-up of 28 months (IQR 14-40). Most patients had locally advanced disease (PO-SBRT 60% high risk and 40% intermediate risk, WP-SBRT 79% node positive and 21% high risk). Median SBRT dose was 36.25Gy (IQR 35-36.25) to the prostate (EQD2=90.6Gy, a/b=1.5Gy) and simultaneous integrated 25Gy to the pelvis (EQD2=46.3Gy) in five fractions on alternate days. No grade 3-4 acute toxicities were observed except one grade 3 urinary obstruction (PO-SBRT). WP-SBRT was associated with significantly higher acute grade 2 gastrointestinal toxicity (29.4% vs 14.7%, p=0.008) and late grade 2 urinary toxicity (45.6% vs 25.0%, p=0.003). Both the groups had low incidence of late grade 3 toxicities (urinary 2.5%, gastrointestinal 1%).
WP-SBRT was associated with significantly higher acute gastrointestinal and late urinary toxicity as compared to PO-SBRT, though overall incidence of severe toxicity was low.
International journal of radiation oncology, biology, physics. 2022 Jun 17 [Epub ahead of print]
Vedang Murthy, Ketaki Adsul, Priyamvada Maitre, Aarushi Singhla, Pallavi Singh, Gitanjali Panigrahi, Vysakh Raveendran, Reena Phurailatpam
Department of Radiation Oncology. Electronic address: ., Department of Radiation Oncology., Department of Radiation Oncology. Electronic address: ., Department of Medical Physics, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India.