Mundt Arno J, Mell Loren K, Roeske John C
Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL 60637, USA.
Int J Radiat Oncol Biol Phys. 2003 Aug 1;56(5):1354-60. doi: 10.1016/s0360-3016(03)00325-0.
To provide a preliminary analysis of chronic gastrointestinal (GI) toxicity in gynecology patients treated with intensity-modulated whole pelvic radiation therapy (IM-WPRT).
Between February 2000 and August 2001, 36 gynecology patients received IM-WPRT. All patients underwent a contrast-enhanced computed tomography scan, and a clinical target volume (CTV) was contoured consisting of the upper vagina, parametria, uterus (if present), and presacral and pelvic lymph node regions. The CTV was expanded by 1 cm to create a planning target volume (PTV). Seven or 9-field IM-WPRT plans were generated. IM-WPRT plans were highly conformal, providing excellent coverage of the PTV and considerable sparing of normal tissues, including the small bowel and rectum. Chronic GI toxicity was scored: 0 (no symptoms), 1 (mild symptoms, no medications required), 2 (moderate symptoms, medications required), and 3 (severe symptoms, hospitalization, surgery required). Chronic GI toxicity in 30 gynecology patients treated with conventional WPRT patients before the implementation of IM-WPRT was also evaluated. Median follow-up in the IM-WPRT and WPRT groups were 19.6 and 30.2 months, respectively.
The IM-WPRT and WPRT groups were well balanced in terms of most patient and treatment factors, including age, site, stage, chemotherapy, WPRT dose, and brachytherapy, except for a higher frequency of surgery (75 vs. 54%, p = 0.02) in the IM-WPRT group. Overall, IM-WPRT patients had a lower rate of chronic GI toxicity (11.1 vs. 50.0%, p = 0.001) than WPRT patients. The percentage of IM-WPRT patients with Grade 1, 2, and 3 toxicity were 8.3%, 2.8%, and 0%, respectively. Corresponding percentages in the WPRT group were 30.0%, 16.7%, and 3.3%, respectively. The only other factor correlated with chronic GI toxicity was age (p = 0.02). On multivariate (logistic regression) analysis controlling for age and other clinical factors, IM-WPRT retained its statistical significance (p = 0.01; odds ratio 0.16; 95% confidence interval 0.04, 0.67)
Our results suggest that IM-WPRT is associated with less chronic GI toxicity than conventional WPRT in patients with gynecologic malignancies. However, longer follow-up and more patients are clearly needed to ascertain whether the benefits of IM-WPRT treatment seen here translate into true long-term reductions in chronic GI toxicity.
对接受调强全盆腔放射治疗（IM-WPRT）的妇科患者的慢性胃肠道（GI）毒性进行初步分析。
2000年2月至2001年8月期间，36例妇科患者接受了IM-WPRT。所有患者均接受了增强计算机断层扫描，并勾勒出临床靶区（CTV），包括上阴道、宫旁组织、子宫（如有）以及骶前和盆腔淋巴结区域。CTV向外扩展1 cm以创建计划靶区（PTV）。生成了七野或九野IM-WPRT计划。IM-WPRT计划具有高度适形性，能很好地覆盖PTV，并能显著减少包括小肠和直肠在内的正常组织受照剂量。对慢性GI毒性进行评分：0（无症状）、1（轻度症状，无需用药）、2（中度症状，需要用药）和3（重度症状，需要住院、手术）。还评估了在实施IM-WPRT之前接受传统全盆腔放射治疗（WPRT）的30例妇科患者的慢性GI毒性。IM-WPRT组和WPRT组的中位随访时间分别为19.6个月和30.2个月。
IM-WPRT组和WPRT组在大多数患者和治疗因素方面，包括年龄、部位、分期、化疗、WPRT剂量和近距离放疗，均具有良好的平衡性，但IM-WPRT组的手术频率较高（75%对54%，p = 0.02）。总体而言，IM-WPRT患者的慢性GI毒性发生率低于WPRT患者（11.1%对50.0%，p = 0.001）。IM-WPRT组1级、2级和3级毒性的患者百分比分别为8.3%、2.8%和0%。WPRT组的相应百分比分别为30.0%、16.7%和3.3%。与慢性GI毒性相关的唯一其他因素是年龄（p = 0.02）。在控制年龄和其他临床因素的多因素（逻辑回归）分析中，IM-WPRT仍具有统计学意义（p = 0.01；优势比0.16；95%置信区间0.04，0.67）。
我们的结果表明，在妇科恶性肿瘤患者中，IM-WPRT与传统WPRT相比，慢性GI毒性较小。然而，显然需要更长时间的随访和更多患者，以确定此处所见的IM-WPRT治疗的益处是否能转化为慢性GI毒性的真正长期降低。
