Xu Benhua, Guo Yuyan, Chen Yuangui, Lu Haijie, Tang Tianlan, Yue Zhicao, Guan Guoxian, Chi Pan, Lin Chi
Department of Radiation Oncology, The Fujian Medical University Union Hospital, Fuzhou, Fujian, P.R. China, 350001.
Institute of Life Sciences, Fuzhou University, Fuzhou, Fujian, P.R. China, 350108.
Radiat Oncol. 2015 Dec 18;10:257. doi: 10.1186/s13014-015-0566-6.
The small bowel (SB) represents the most important dose-limiting structure in pelvic radiotherapy (RT). However, we observed that the majority of rectal cancer patients who received preoperative pelvic intensity modulated RT (IMRT) developed acute tenesmus without watery diarrhea. The objective of this study is to determine if the RT dose to SB affects the acute lower gastrointestinal toxicity (ALGIT) in rectal cancer patients who received neoadjuvant concurrent chemotherapy-IMRT. We will also evaluate if patient and tumor factors affect the ALGIT.
We retrospectively analyzed 63 rectal cancer patients that consecutively received preoperative IMRT (45 Gy for pelvis and 50 Gy for gross tumor in 25 fractions) with concurrent chemotherapy (oxaliplatin 130 mg/m(2) on day 1 and capecitabine 825 mg/m(2), twice per day from day 1 to day 14, week 1 and 4) between May 2012 and May 2013. The ALGIT was assessed with Common Terminology Criteria for Adverse Events version 3. The patients were stratified into two groups (with and without grade ≥2 ALGIT). The effect of SB volume receiving 5 to 40 Gy (V5 to V40) at a 5 Gy interval dose level on grade ≥2 ALGIT was evaluated. The volume of small bowel is defined as the volume of the small bowel loop. Other factors evaluated include patient's age and gender, tumor size and location and preexisting number of daily bowel movements.
Overall, grade ≥2 ALGIT occurred in 57 % (36/63) patients. There was no significant difference between the two groups of patients (with and without grade ≥2 ALGIT) in SB V5 to V40, patient's age and gender, tumor location and preexisting number of daily bowel movements. There was a significant difference between the two groups of patients in tumor volume (with grade ≥2 ALGIT: 115.5 ± 85.5 cm(3) versus without grade ≥2 ALGIT: 58.5 ± 25.2 cm(3), p = 0.0001). Multivariate analysis revealed no association between the dose SB received (V5 to V40) and the grade ≥2 ALGIT after adjusting for the tumor volume.
With IMRT technique used in rectal cancer patients undergoing preoperative chemo-radiotherapy, the acute lower GI toxicity is not associated with small bowel V5 to V40; instead it is associated with rectal tumor size.
在盆腔放疗（RT）中，小肠（SB）是最重要的剂量限制结构。然而，我们观察到，大多数接受术前盆腔调强放疗（IMRT）的直肠癌患者出现了急性里急后重但无水样腹泻。本研究的目的是确定对小肠的放疗剂量是否会影响接受新辅助同步化疗-IMRT的直肠癌患者的急性下消化道毒性（ALGIT）。我们还将评估患者和肿瘤因素是否会影响ALGIT。
我们回顾性分析了2012年5月至2013年5月期间连续接受术前IMRT（盆腔45 Gy，25次分割，大体肿瘤50 Gy）并同步化疗（第1天奥沙利铂130 mg/m²，第1天至第14天、第1周和第4周卡培他滨825 mg/m²，每日2次）的63例直肠癌患者。采用不良事件通用术语标准第3版评估ALGIT。将患者分为两组（有和无≥2级ALGIT）。评估了小肠在5 Gy间隔剂量水平下接受5至40 Gy（V5至V40）的体积对≥2级ALGIT的影响。小肠体积定义为小肠袢的体积。评估的其他因素包括患者的年龄和性别、肿瘤大小和位置以及术前每日排便次数。
总体而言，57%（36/63）的患者发生了≥2级ALGIT。两组患者（有和无≥2级ALGIT）在小肠V5至V40、患者年龄和性别、肿瘤位置以及术前每日排便次数方面无显著差异。两组患者的肿瘤体积存在显著差异（≥2级ALGIT组：115.5±85.5 cm³，无≥2级ALGIT组：58.5±25.2 cm³，p = 0.0001）。多因素分析显示，在调整肿瘤体积后，小肠接受的剂量（V5至V40）与≥2级ALGIT之间无关联。
对于接受术前放化疗的直肠癌患者，采用IMRT技术时，急性下消化道毒性与小肠V5至V40无关；相反，它与直肠肿瘤大小有关。
