Radiation doses to the bladder and rectum were reduced with intensity-modulated radiotherapy (IMRT) compared with 3-dimensional conformal radiotherapy (3DCRT) in men receiving hypofractionated radiotherapy for prostate cancer, a study published online ahead of print in the journal Cancer has shown. In addition, acute and late grade 2 and higher gastrointestinal (GI) and genitourinary (GU) toxicity were lower with IMRT compared with 3DCRT.1
In this study, 215 men with localized prostate cancer were randomized to receive hypofractionated radiotherapy at 2.8 Gy per fraction to a total dose of 70 Gy (25 fractions) using either IMRT (n = 109) or 3DCRT (n = 106). The researchers sought to evaluate the incidence of acute and late GI and GU toxicity according to modified Radiation Therapy Oncology Group criteria.
The rate of grade 2 or higher acute GU toxicity was 27% vs 9% in the 3DCRT and IMRT arms, respectively, (P = .001). Rate of grade 2 or higher acute GI toxicity was 24% vs 7% in the 3DCRT and IMRT arms, respectively, (P = .001).
Maximal rate of grade 2 or higher late GU toxicity during the entire follow-up period was 12.3% vs 3.7% in the 3DCRT and IMRT arms, respectively, (P = .02) and 21.7% vs 6.4% in the 3DCRT and IMRT arms, respectively, (P = .001) for late GI toxicity during the follow-up period. In addition, 5-year rate of freedom from biochemical failure was 94.3% and 95.4% in the 3DCRT and IMRT arms, respectively, (P = .678).
1. Viani GA, Viana BS, Martin JE, Rossi BT, Zuliani G, Stefano EJ. Intensity-modulated radiotherapy reduces toxicity with similar biochemical control compared with 3-dimensional conformal radiotherapy for prostate cancer: a randomized clinical trial [published online ahead of print March 29, 2016]. Cancer. doi:10.1002/cncr.29983.