Prasad Shreya, Cambridge Lajhem, Huguet Florence, Chou Joanne F, Zhang Zhigang, Wu Abraham J, O'Reilly Eileen M, Allen Peter J, Goodman Karyn A
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
Department of Radiation Oncology, Tenon Hospital, APHP, University Paris VI, Paris, France.
Pract Radiat Oncol. 2016 Mar-Apr;6(2):78-85. doi: 10.1016/j.prro.2015.09.006. Epub 2015 Sep 25.
We compared gastrointestinal (GI) and hematologic toxicity in patients with locally advanced pancreas cancer (LAPC) undergoing definitive chemoradiation using intensity modulated radiation therapy (IMRT) or 3-dimensional conformal radiation therapy (3D-CRT) planning.
We retrospectively studied 205 patients with LAPC undergoing IMRT (n = 134) and 3D-CRT (n = 71) between May 2003 and March 2012. Patient, tumor, and treatment characteristics and acute GI/hematology toxicity according to the Common Terminology Criteria for Adverse Events, version 3.0, were recorded. Multivariable logistic regression models were used to test association between acute grade 2+ GI and hematologic toxicity outcomes and predictors. Propensity score analysis for grade 2+ GI toxicity was performed to reduce bias for confounding variables: age, gender, radiation dose, field size, and chemotherapy type.
Median follow-up time for survivors was 22 months and was similar between groups. Median RT dose was significantly higher for IMRT versus 3D-CRT (5600 cGy vs 5040 cGy, P < .001); concurrent chemotherapy was mainly gemcitabine (56%) or 5-fluorouracil (38%). Grade 2+ GI toxicity occurred in 34% (n = 24) of 3D-CRT compared with 16% (n = 21) of IMRT patients. Using propensity score analysis, 3D-CRT had significantly higher grade 2+ GI toxicity (odds ratio, 1.26; 95% confidence interval, 1.08-1.45; P = .001). Grade 2+ hematologic toxicity was similar between IMRT and 3D-CRT groups, but was significantly greater in recipients of concurrent gemcitabine than in 5-fluorouracil (62% vs 29%, P < .0001).
IMRT is associated with significant lower grade 2+ GI toxicity versus 3D-CRT for patients undergoing definitive chemoradiation therapy for LAPC. Because IMRT is better tolerated at higher doses and may allow further dose escalation, potentially improving local control for this aggressive disease. Further prospective studies of dose-escalated chemoradiation using IMRT are warranted.
我们比较了采用调强放射治疗（IMRT）或三维适形放射治疗（3D-CRT）计划进行根治性放化疗的局部晚期胰腺癌（LAPC）患者的胃肠道（GI）和血液学毒性。
我们回顾性研究了2003年5月至2012年3月期间接受IMRT（n = 134）和3D-CRT（n = 71）的205例LAPC患者。记录患者、肿瘤和治疗特征以及根据不良事件通用术语标准3.0版的急性GI/血液学毒性。使用多变量逻辑回归模型测试急性2级及以上GI和血液学毒性结果与预测因素之间的关联。对2级及以上GI毒性进行倾向评分分析以减少混杂变量（年龄、性别、放射剂量、照射野大小和化疗类型）的偏倚。
幸存者的中位随访时间为22个月，两组之间相似。IMRT组的中位放疗剂量显著高于3D-CRT组（5600 cGy对5040 cGy，P <.001）；同步化疗主要为吉西他滨（56%）或5-氟尿嘧啶（38%）。3D-CRT组中2级及以上GI毒性发生率为34%（n = 24），而IMRT组为16%（n = 21）。使用倾向评分分析，3D-CRT的2级及以上GI毒性显著更高（优势比，1.26；95%置信区间，1.08 - 1.45；P =.001）。IMRT组和3D-CRT组之间2级及以上血液学毒性相似，但同步接受吉西他滨治疗的患者显著高于接受5-氟尿嘧啶治疗的患者（62%对29%，P <.0001）。
对于接受LAPC根治性放化疗的患者，与3D-CRT相比，IMRT与显著更低的2级及以上GI毒性相关。因为IMRT在更高剂量下耐受性更好，可能允许进一步提高剂量，潜在地改善这种侵袭性疾病的局部控制。有必要对使用IMRT的剂量递增放化疗进行进一步的前瞻性研究。
