• Shinya Sutani, Toshio Ohashi, Masanori Sakayori, Tomoya Kaneda, Shoji Yamashita, Tetsuo Momma, Takashi Hanada, Yutaka Shiraishi, Junichi Fukada, Mototsugu Oya, and Naoyuki Shigematsu.
• Department of Radiology, Keio University School of Medicine, Japan.
• Radiother Oncol. 2015 Nov 1; 117 (2): 270-6.

PurposeTo compare late genitourinary (GU) and gastrointestinal (GI) toxicity following different prostate cancer treatment modalities.Materials And MethodsThis study included 1084 consecutive prostate cancer patients treated with conventional radiotherapy, intensity-modulated radiotherapy (IMRT), permanent iodine-125 implantation (PI) alone, and PI combined with external beam radiotherapy (PI+EBRT). The effects of treatment- and patient-related factors on late grade ⩾ 2 (G2+) GU/GI toxicity risk were assessed.ResultsThe median follow-up was 43 months (range, 12-97 months). Compared to the PI+EBRT, there was significantly less G2+ GU toxicity in the conventional radiotherapy (hazard ratio [HR] = 0.39; 95% CI, 0.20-0.77) and the IMRT (HR=0.45, 95% CI, 0.27-0.73). Compared to the PI+EBRT, there was significantly more G2+ GI toxicity in the IMRT (HR = 2.38; 95% CI, 1.16-4.87). In PI-related groups, prostate equivalent dose in 2 Gy fractions was a significant predictor of G2+ GU toxicity (p = 0.001), and the rectal volume receiving more than 100% of the prescribed dose was a significant predictor of G2+ GI toxicity (p = 0.001).ConclusionThe differences in the late G2+ GU/GI risk cannot be explained by the differences in treatment modalities themselves, but by the total radiation dose to the GU/GI tract, which had a causal role in the development of late G2+ GU/GI toxicity across all treatment modality groups.Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

32 keywords...

hide…