論文の公開元へ前立腺癌に対する強度変調放射線治療における晩期直腸有害事象の発生予測因子
概要
Purpose : To identify predictive factors for late rectal toxicity in prostate cancer patient who underwent intensitymodulated radiation therapy (IMRT). Methods : 415 prostate cancer patients who underwent IMRT between November 2008 and September 2019 were included. All patients underwent definitive radiation therapy with a total prescribed dose of 78 Gy, and 2 Gy per fraction. We analyzed the relationship between late rectal toxicity and the following factors : National Comprehensive Cancer Network (NCCN) risk classification, use of anticoagulants, radiation methods and various dose-volume histogram parameters. Results : Median follow-up period was 46 months (3-133). Grade ≥ 2 late rectal adverse events occurred in 8.0 ％ (n＝33). Univariate analysis revealed that NCCN high-risk group (P＝0.026) and low percentage of bladder wall volume irradictaed 70 Gy or more to total bladder wall volume (BW V70Gy％) were significantly associated with increased rate of Grade ≥ 2 late rectal toxicity (P＝0.026 and 0.036, respectively). Multivariate analysis showed that both of them were independently accociated with the rate of the toxicity (P＝0.016 and 0.033, respectively). Conclusion : NCCN high-risk group and low BW V70Gy％ might be predictive factors for Grade ≥ 2 late rectal toxicity.
