断层径照治疗局部中晚期下咽癌的剂量学研究  

A dosimetric study on TOMODirect treating locally advanced hypopharyngeal cancer

作　　者：吴府容 周宪 罗焱 谢悦 何亚男 罗茜 Wu Furong;Zhou Xian;Luo Yan;Xie Yue;He Yanan;Luo Qian(Department of Radiation Oncology,Chongqing University Cancer Hospital)

机构地区：[1]重庆大学附属肿瘤医院肿瘤放射治疗中心,重庆400030

出　　处：《重庆医科大学学报》2020年第8期1223-1227,共5页Journal of Chongqing Medical University

基　　金：重庆市科卫联合医学科研资助项目(编号:2018MSXM041、2019MSXM040)。

摘　　要：目的:分析断层径照(TOMODirect,TD)治疗局部中晚期下咽癌的剂量学特性及其肿瘤控制概率(tumor control probability,TCP),评估TD治疗局部中晚期下咽癌的临床可行性。方法:随机选取26例局部中晚期下咽癌患者,分别采用螺旋断层(TOMOHelical,TH)和TD设计放疗计划。采用配对t检验对比分析2组计划的靶区包络质量、危及器官(organs at risk,OAR)保护、计划执行效率及TCP。结果:TD和TH治疗计划的各项指标均满足临床要求。与TH相比,TD计划中PTV1的靶区适形指数略差(P=0.009),平均剂量增大0.48%(P=0.010)。TH和TD计划中SIB和PTV2的各参数剂量差异不大,且均无统计学差异(P>0.05)。TD中除脊髓的最大剂量较TH计划增加3.64%(P=0.044),以及身体的V5 Gy和V10 Gy分别降低3.98%(P=0.002)和3.46%(P=0.002)之外,2种计划中其他危及器官的剂量均差异不大,且无统计学差异(P>0.05)。TD比TH的机器跳数减少8.04%(P=0.000),但治疗时间却增加54.08 s(P=0.000)。TD和TH的TCP均值分别为94.74%和94.71%,两者无统计学差异(P>0.05)。结论:TD可以取得与TH相接近的靶区包络质量和危及器官受量,降低了低剂量区的范围,虽治疗时间有所延长,但降低了机器跳数,且平均肿瘤控制概率接近。TD可能是治疗局部中晚期下咽癌的一种优选放疗方式,在临床中值得推广应用。Objective:To analyze the dosimetric characteristics of TOMODirect(TD) on the treatment of locally advanced hypopha ryngeal cancer and its tumor control probability(TCP),and to evaluate its clinical feasibility. Methods:Twenty-six patients with locally advanced hypopharyngeal cancer were randomly selected. TOMOHelical(TH) and TD were used to design radiotherapy plan. The paired t test was used in two different plans to analyze target envelope quality,organs at risk(OAR) protection,plan process and TCP.Results:All indexes of TD and TH treatment plans met clinical requirements. Compared with TH,the conformal index of PTV1 in TD plan was slightly worse(P=0.009),and the average dose was increased by 0.48%(P=0.010). Dose differences of SIB and PTV2 in TH and TD plans were not significant,and has no statistical significance(P>0.05). Compared with TH plan,only the maximum dose of spinal cord in TD plan was increased by 3.64%(P=0.044),and V5 Gyand V10 Gywere decreased by 3.98%(P=0.002) and 3.46%(P=0.002),respectively,while doses of other OARs in two plans had no significant difference,without statistical significance(P>0.05). The number of monitor unit in TD plan was decreased by 8.04%( P =0.000) when compared with TH plan,but the treatment time was increased by 54.08 seconds(P=0.000). Mean values of TCP in TD and TH plan were 94.74% and 94.71%,respectively,without statistically significant difference(P >0.05). Conclusion:TD can obtain the similar target envelope and organ at risk with TH,reducing the volume of the low-dose area. Although the treatment time is prolonged,the number of monitor unit is reduced,and the average TCP is similar. TD may be a preferred radiotherapy method for treating locally advanced hypopharyngeal cancer,which is worthy of clinical promotion and application.

关 键 词：局部中晚期下咽癌 断层径照 危及器官 肿瘤控制概率 剂量学 

分 类 号：R815[医药卫生—放射医学]