影响宫颈癌调强放射治疗相关急性放射性肠炎的临床因素及剂量学参数分析

Analysis of Clinical Factors and Dosimetry Parameters Influencing Acute Radiation Enteritis Associated with Intensity-modulated Radiotherapy for Cervical Cancer

目的回顾性分析宫颈癌调强放射治疗(Intensity-modulated radiotherapy,IMRT)中急性放射性肠炎(radiation enteritis,RE)的发生发展与临床因素、剂量-体积参数的关系。方法收集苏州大学附属第一医院放疗科接受盆腔局部放疗的宫颈癌患者50例,根据不良反应事件评价标准(CTCAE 5.0)统计患者IMRT相关性急性放射性肠炎。用剂量体积直方图评价标准计划下患者的危及器官受照剂量体积。分析小肠V_(20)、小肠V_(30)、小肠V_(40)、结肠V_(40)、直肠V_(40)预测急性RE及严重急性RE的可行性。结果50例宫颈癌患者IMRT主要放疗相关不良反应包括胃肠道毒性,所有不良反应为1~3级,未出现3级以上不良反应。放疗开始后第2周,腹泻、腹痛、结肠炎、肛门坠胀、便血的发生率分别为28%、22%、8%、20%、6%,第4周时发生率为56%、36%、16%、26%、18%,外照射结束时分别为74%、42%、24%、34%及30%。发生SARE的宫颈癌患者放疗不良反应主要体现在1~3级的腹痛、结肠炎、肛门坠胀与便血(P均<0.05)。发生SARE患者年龄显著小于未发生SARE患者,同步放化疗(concurrent chemoradiotherapy,CCRT)患者SARE发生率显著高于序贯放化疗(sequential chemoradiotherapy,SCRT)患者(P均<0.05)。SARE组小肠V_(20)、V_(25)、V_(30)、V_(40),直肠V_(40),结肠V_(40)高于未发生SARE患者,但统计学未见明显差异(P均>0.05)。通过ROC曲线分析小肠V_(20)、小肠V_(30)、小肠V_(40)、结肠V_(40)、直肠V_(40)预测急性/严重急性RE发生的特异性及灵敏度,曲线下面积AUC均<0.60,且P均>0.05,表明单一OAR剂量-体积参数尚不足以预测急性/严重急性RE的发生。结论宫颈癌IMRT胃肠道及血液系统毒性发生的时间模型随放疗开展而逐渐递增,在放疗结束时到达峰值,主要不良反应为腹泻、腹痛、结肠炎、肛门坠胀、便血。年轻患者、CCRT宫颈癌患者SARE发生率增高。

Objective To retrospectively analyze the relationship between the occurrence and development of acute radiation enteritis(radiation enteritis,RE)and clinical factors and dose-volume parameters in intensity-modulated radiotherapy(IMRT)for cervical cancer.Methods A total of 50 patients with cervical cancer who received pelvic local radiotherapy were collected,and the IMRT-related acute RE was counted according to the adverse event evaluation criteria(CTCAE 5.0).The dose volume histogram was used to evaluate the dose volume to the organs at risk in the standard plan.The feasibility of small intestinal V_(20),small intestinal V_(30),small intestinal V_(40),colonic V_(40),and rectal V_(40) in predicting acute RE and severe acute RE was analyzed.Results The main radiotherapy-related adverse reactions of IMRT in 50 patients with cervical cancer included gastrointestinal toxicity.All adverse reactions were grade 1 to grade 3,and no adverse reactions were grade 3 or above.The Incidences of diarrhea,abdominal pain,colitis,anal bulge and hematochezia were 28%,22%,8%,20%and 6%respectively at the second week after radiotherapy,and 56%,36%,16%,26%and 18%at the fourth week after radiotherapy.The end rates of external irradiation were 74%,42%,24%,34%and 30%,respectively.Adverse reactions of radiotherapy in cervical cancer patients with SARE were mainly manifested in grade 1-3 abdominal pain,colitis,anal swelling and blood in stool(all P<0.05).The age of patients withSARE was significantly younger than those patients without SARE,and the incidence of SARE in patients with concurrent chemoradiotherapy(CCRT)was significantly higher than that in patients with sequential chemoradiotherapy(SCRT)(all P<0.05).Small intestine V_(20),V_(25),V_(30),V_(40),rectum V_(40),and colon V_(40) in SARE group were higher than those in patients without SARE,but there was no significant difference in statistics(all P>0.05).The ROC curve was used to analyze the specificity and sensitivity of small intestine V_(20),small intestine V_(30),small intestine V_(40),colon V_(40),and rectum V_(40) in predicting the occurrence of acute/severe acute RE.The area under the curve AUC was all less than 0.60,and both P value were greater than 0.05,indicating a single OAR dose volume parameter was not yet sufficient to predict the occurrence of acute/severe acute RE.Conclusions The time model of gastrointestinal and hematological toxicity of cervical cancer IMRT gradually increases with the development of radiotherapy,and reaches the peak at the end of radiotherapy.The main adverse reactions are diarrhea,abdominal pain,colitis,anal swelling,and blood in the stool.The incidence of SARE increased in young patients and CCRT patients of cervical cancer.