Yang T Jonathan, Oh Jung Hun, Son Christina H, Apte Aditya, Deasy Joseph O, Wu Abraham, Goodman Karyn A
Department of Radiation Oncology.
Gastrointest Cancer Res. 2013 Sep;6(5-6):129-36.
This study was conducted to identify the factors associated with acute gastrointestinal (GI) toxicity during pelvic chemoradiotherapy (PCRT) in patients with rectal cancer.
We analyzed 177 patients with rectal cancer treated from 2007 through 2010. Clinical information, including weekly diarrhea and proctitis toxicity grade during PCRT, was recorded. GI structures including bowel and anal canal were contoured. The associations between toxicity and clinical and dosimetric predictors were tested.
The median age was 60; 76 patients were women; 98 were treated with intensity-modulated radiotherapy (IMRT) and 79 with 3D conformal RT (3DCRT). A higher rate of grade 2+ diarrhea was observed in the women, starting at week 4 (24% women vs. 11% men, P = .01; week 5: 33% vs. 12%, P = .002), as well as in all the patients treated with 3DCRT (22% vs. 12% IMRT, P = .03; week 5: 32% vs. 11%, P = .001). On multivariate analysis, the normal tissue complication probability (NTCP) model including bowel V45 (bowel volume receiving ≥45 Gy) showed that being female, and use of 3DCRT, was most predictive of grade 2+ diarrhea (area under the curve [AUC] = 0.76; R S = 0.35; P < .001). A higher rate of grade 2+ proctitis was seen in patients <60 years of age starting at week 3 (21% vs. 9%, P = .02; week 4: 35% vs. 16%, P = .003). The NTCP model including anal canal V15 and younger age was most predictive of grade 2+ proctitis (AUC = 0.67; R S = 0.25; P < .001).
Women and all patients who were treated with 3DCRT had higher rates of grade 2+ diarrhea, and the younger patients had a higher rate of grade 2+ proctitis during PCRT. The use of more stringent dosimetric constraints in higher risk patients is a strategy for minimizing toxicity.
本研究旨在确定直肠癌患者盆腔放化疗（PCRT）期间急性胃肠道（GI）毒性的相关因素。
我们分析了2007年至2010年期间接受治疗的177例直肠癌患者。记录了临床信息，包括PCRT期间每周的腹泻情况和直肠炎毒性分级。对包括肠管和肛管在内的胃肠道结构进行了轮廓勾画。测试了毒性与临床及剂量学预测因素之间的关联。
中位年龄为60岁；76例为女性；98例接受调强放疗（IMRT），79例接受三维适形放疗（3DCRT）。女性从第4周开始出现2级及以上腹泻的发生率较高（女性为24%，男性为11%，P = 0.01；第5周：33%对12%，P = 0.002），接受3DCRT治疗的所有患者也是如此（22%对IMRT的12%，P = 0.03；第5周：32%对11%，P = 0.001）。多因素分析显示，包含肠管V45（接受≥45 Gy照射的肠管体积）的正常组织并发症概率（NTCP）模型表明，女性和使用3DCRT最能预测2级及以上腹泻（曲线下面积[AUC]=0.76；R S = 0.35；P < 0.001）。60岁以下患者从第3周开始出现2级及以上直肠炎的发生率较高（21%对9%，P = 0.02；第4周：35%对16%，P = 0.003）。包含肛管V15和较年轻年龄的NTCP模型最能预测2级及以上直肠炎（AUC = 0.67；R S = 0.25；P < 0.001）。
女性和所有接受3DCRT治疗的患者在PCRT期间出现2级及以上腹泻的发生率较高；年龄较小的患者出现2级及以上直肠炎的发生率较高。在高风险患者中使用更严格的剂量学限制是将毒性降至最低的一种策略。
