Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213, USA.
Oncology. 2013;85(1):1-7. doi: 10.1159/000348387. Epub 2013 Jun 1.
To determine the dosimetric parameters predictive of acute gastrointestinal (GI) toxicity in anal cancer patients treated with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy.
Fifty-eight anal cancer patients were treated with concurrent chemotherapy and IMRT. The bowel was delineated on the planning CT and included the intestinal cavity. Regression models with multiple independent predictors were used to test associations of clinical factors and dosimetric parameters with clinically significant GI toxicity (grade ≥3). Significant dosimetric factors were fitted to a normal tissue complication probability curve using a logit function and subsequently analyzed at multiple bowel volumes to determine the threshold for clinically significant GI toxicity.
Two patients (3.4%) experienced no acute GI toxicity, whereas 20 (34.5%) experienced grade 1 toxicity, 20 (34.5%) experienced grade 2, 16 (27.6%) experienced grade 3 and none experienced grade 4. Analysis showed that the volumes of bowel receiving 30 Gy (V30) and 40 Gy (V40) both correlated with clinically significant acute GI toxicity. In patients whose V30 was >310 cm(3), the rate of clinically significant acute GI toxicity was 38.9%, compared to 9.1% if V30 was ≤310 cm(3) (p = 0.016). If V40 was ≤70 cm(3), the rate of acute grade ≥3 toxicity was 6.3%, versus 35.7% if V40 was >70 cm(3) (p = 0.045).
This analysis demonstrates that the bowel dosimetric parameters are associated with clinically significant acute GI toxicity when IMRT is used in the management of anal cancer patients.
确定接受调强放疗（IMRT）和同期化疗治疗的肛门癌患者中预测急性胃肠道（GI）毒性的剂量学参数。
58 例肛门癌患者接受同期化疗和 IMRT 治疗。在计划 CT 上对肠道进行描绘，并包括肠道腔。使用具有多个独立预测因子的回归模型来测试临床因素和剂量学参数与临床显著 GI 毒性（≥3 级）的关联。使用对数函数将显著的剂量学因素拟合到正常组织并发症概率曲线中，并随后在多个肠道体积上进行分析，以确定临床显著 GI 毒性的阈值。
有 2 例（3.4%）患者无急性 GI 毒性，20 例（34.5%）患者出现 1 级毒性，20 例（34.5%）患者出现 2 级毒性，16 例（27.6%）患者出现 3 级毒性，无一例患者出现 4 级毒性。分析表明，肠道接受 30 Gy（V30）和 40 Gy（V40）的体积均与临床显著急性 GI 毒性相关。在 V30 ＞310 cm3 的患者中，临床显著急性 GI 毒性的发生率为 38.9%，而 V30≤310 cm3 的患者为 9.1%（p=0.016）。如果 V40≤70 cm3，则急性≥3 级毒性的发生率为 6.3%，而 V40＞70 cm3 的发生率为 35.7%（p=0.045）。
本分析表明，在管理肛门癌患者时使用 IMRT 时，肠道剂量学参数与临床显著的急性 GI 毒性相关。
