SEER-Medicare database analysis of toxicity of proton beam therapy and intensity-modulated radiation therapy for prostate cancer

Previous studies have not demonstrated a benefit of proton beam therapy (PBT) compared with intensity-modulated radiation therapy (IMRT) for prostate cancer. An updated comparison of gastrointestinal (GI) and genitourinary (GU) toxicity is needed. Analysis of patient data in the SEER-Medicare database (2010-2017) found that the frequency of GI toxicity for IMRT versus PBT was 3.5% versus 2.5% at 6 months (p=0.18), 9.5% versus 10.2% at 12 months (p=0.18), and 20.5% versus 23.4% at 24 months (p=0.11). The frequency of GU toxicity for IMRT versus PBT was 6.8% versus 5.7% at 6 months (p=0.30), 14.3% versus 12.2% at 12 months (p=0.13), and 28.2% versus 25.8% at 24 months (p=0.21). The authors conclude that in this observational analysis, there were no statiscally significant differences between PBT and IMRT in terms of GI or GU toxicity.