Zhang Yan, Zhu Wei-guo, Han Ji-hua, Zhang Xiao-ye, Tao Guang-zhou, Li Tao, Yu Chang-hua
Department of Radiation Oncology, The First People's Hospital of Huai'an, Nanjing Medical University, Jiangsu Huai'an 223300, China.
Zhonghua Wei Chang Wai Ke Za Zhi. 2013 Mar;16(3):268-72.
To elucidate the application and the dosimetry characteristic of the simplified intensity modulated radiation therapy (sIMRT) for gastric cancer after operation, and to compare the dose distribution with intensity modulated radiation therapy (IMRT) and three-dimension conformal radiation therapy (3D-CRT).
Twelve patients with gastric cancer after operation were enrolled in this study. 3D-CRT plan, 5-field IMRT plans (20 degree, 80 degree, 180 degree, 280 degree, 340 degree) and 5-field sIMRT plans (20 degree, 80 degree, 180 degree, 280 degree, 340 degree) were performed for each patient. The conformal index (CI), heterogeneity index (HI) of the planning target volume (PTV) and the dose of normal organs were analyzed with the dose volume histogram (DVH). The total MU and treatment time were also compared.
The sIMRT and IMRT plans had comparable CI (sIMRT>IMRT>3D-CRT), and showed better dose conformity but worse homogeneity than 3D-CRT. The percentage of volume receiving 20 Gy, 25 Gy, 30 Gy and 40 Gy by liver were significantly lower in sIMRT than that in 3D-CRT, and comparable to IMRT. All the dose volumes to kidneys with sIMRT were still significantly lower as compared to 3D-CRT, and comparable to IMRT. The sIMRT plan was better than IMRT plan in total MU and treatment time.
sIMRT has comparable dose distribution in patients with gastric cancer to IMRT, but is significantly better than 3D-CRT. Treatment time of sIMRT is the shortest. So sIMRT technique can be applied more simply.
阐明简化调强放射治疗（sIMRT）在胃癌术后的应用及剂量学特点，并将其剂量分布与调强放射治疗（IMRT）和三维适形放射治疗（3D-CRT）进行比较。
本研究纳入12例胃癌术后患者。为每位患者制定3D-CRT计划、5野IMRT计划（20度、80度、180度、280度、340度）和5野sIMRT计划（20度、80度、180度、280度、340度）。利用剂量体积直方图（DVH）分析计划靶区（PTV）的适形指数（CI）、不均匀性指数（HI）以及正常器官的剂量。同时比较总跳数（MU）和治疗时间。
sIMRT和IMRT计划的CI相当（sIMRT>IMRT>3D-CRT），与3D-CRT相比，显示出更好的剂量适形性，但均匀性较差。sIMRT组肝脏接受20 Gy、25 Gy、30 Gy和40 Gy剂量的体积百分比显著低于3D-CRT组，与IMRT组相当。sIMRT组肾脏的所有剂量体积仍显著低于3D-CRT组，与IMRT组相当。sIMRT计划在总MU和治疗时间方面优于IMRT计划。
sIMRT在胃癌患者中的剂量分布与IMRT相当，但明显优于3D-CRT。sIMRT的治疗时间最短。因此，sIMRT技术应用更简便。
