头部寡转移瘤无均整器模式剂量学分析  

Dosimetry analysis of FFF mode on head oligo-metastasis

作　　者：侯东梅 殷旭君 张秋杭[1] 徐建堃[1] HOU Dong-mei;YIN Xu-jun;ZHANG Qiuhang(Department of Radiotherapy, Xuanwu Hospital, Capital Medical University, Beijing 100053,China;不详)

机构地区：[1]首都医科大学宣武医院放射治疗科,北京100053

出　　处：《中国医学装备》2022年第6期25-28,共4页China Medical Equipment

摘　　要：目的:分析头部寡转移瘤立体定向放射外科(SRS)中均整器(FF)模式和无均整器(FFF)模式下的剂量学差异,为FFF模式应用于头部寡转移瘤的立体定向放射治疗(SRT)提供依据。方法:选取医院收治的14例行SRT脑部寡转移瘤患者病例资料,将所有患者治疗中目标计划射线类型由FF模式改为FFF模式,其他参数保持不变。比较同一靶区两种模式计划的剂量学分布特征的非均匀性指数(HI)、机器跳数、治疗时间和危及器官(OAR)剂量的差异性。结果:FF和FFF模式下的HI分别为0.091±0.03和0.094±0.03,机器跳数分别为(1202.35±157)MU和(1252.42±177.9)MU,治疗时间分别为(207.64±19.19)s和(170±13.7)s,差异均有统计学意义(t=-2.48,t=-3.18,t=8.65;P<0.05)。两种模式下剂量梯度指数(GI)中GI2000比较差异有统计学意义(t=-2.27,P<0.05),而适形度、剂量跌落梯度、OAR的最大值、最小值和平均值比较差异无统计学意义。两种模式的左眼晶状体、左右内耳的剂量最小值和右内耳的剂量平均值比较,差异均有统计学意义(t=-2.1,t=-2.83,t=-2.29,t=-2.42;P<0.05),FFF模式下OAR剂量低于FF模式下剂量,但差异无统计学意义。结论:FF模式的适形度和均匀性优于FFF模式,但FFF模式剂量跌落和OAR剂量优于FF模式,且治疗时间明显短于FF模式,可确保患者治疗安全。Objective: To analyze the dosimetric difference between flattening filter(FF) mode and flattening filterfree(FFF) mode in stereotactic radiation therapy(SRT) for head oligo-metastasis, so as to provide reference for the application of FFF mode in SRT of head oligo-metastasis. Methods: A total of 14 patients with brain oligo-metastasis who underwent SRT were selected. The type of radiation of all target plans were changed from FF mode to FFF mode,and other parameters were remained. The differences of the heterogeneity index(HI), the monitor unit(MU), the time of therapy and the dose of organ at risk(OAR) of distribution characteristics of dosimetry at the same target region between two kinds of mode plans were further compared. Results: The HIs, MUs and the times of therapy of FF mode and FFF mode were(0.091±0.03 and 0.094±0.03),(1202.35±157 MU and 1252.42±177.9 MU) and(207.64±19.19and 170±13.7), respectively. And the differences of them between two modes were significant(tHI=-2.48, tMU=-3.18,tT=8.65, P<0.05). The difference of GI2000 between two modes was significant(tGI2000=-2.27, P<0.05), while there were no significant differences in the maximum values, minimum values and mean values of the conformity index, the dose Gradient Index and OAR. The differences of minimum dose of the left lens and the left and right inner ears, and the mean value of the doses of right inner ears between two groups were significant(t=-2.1, t=-2.83, t=-2.29, P<0.05),respectively. The OAR dose of FFF mode was lower than that of FF mode, although the difference of that between two groups was no significant. Conclusion: The conformity and uniformity of FF mode are better than those of FFF mode,while the dose decline and OAR dose of FFF mode are better than those of FF mode, and the time of therapy of FFF mode is shorter than that of FF mode, which can ensure the therapeutic safety of patients.

关 键 词：立体定向放射治疗(SRT) 非均整模式(FFF) 剂量 寡转移瘤 

分 类 号：R814.2[医药卫生—影像医学与核医学]