CAJ | 학술논문

目的：探讨多发脑转移癌在治疗中容积弧形调强放疗（VMAT）与适形调强放疗（IMRT）的剂量学特点。方法选择60例确诊的多发脑转移癌患者纳入本研究。所有患者均采用全脑放疗加肿瘤靶区后期加量技术给予处方剂量，全脑放疗30 Gy／10F ，病灶加量20 Gy／10F至生物学剂量59 Gy。每例患者采用同样的剂量学条件限制，分别进行两弧容积弧形调强计划与调强计划设计。通过其剂量学分析评估：靶区覆盖，均匀性及适形性；危及器官（OAR）剂量分布；机器跳数。结果两组治疗计划均能满足临床要求。两组眼球、晶体、视神经、视交叉、腮腺、脑干及外耳道的平均受照剂量相似，差异无统计学意义（P＞0．05）；VMAT组眼球、晶体、腮腺及外耳道的热点剂量小于IMRT组（P＜0．05）。VMAT 组有更少的机器跳数（P＝0．017），照射时间更短。结论 VMAT技术可以满足临床对于多发脑转移瘤的大剂量放射治疗的计划要求；两种方案在靶区适形度、靶区均匀性无明显差别；VMAT组的眼球、晶体、腮腺及外耳道热点剂量更低；VMAT在缩短照射时间方面更具有优势。
목적：탐토다발뇌전이암재치료중용적호형조강방료（VMAT）여괄형조강방료（IMRT）적제량학특점。방법선택60례학진적다발뇌전이암환자납입본연구。소유환자균채용전뇌방료가종류파구후기가량기술급여처방제량，전뇌방료30 Gy／10F ，병조가량20 Gy／10F지생물학제량59 Gy。매례환자채용동양적제량학조건한제，분별진행량호용적호형조강계화여조강계화설계。통과기제량학분석평고：파구복개，균균성급괄형성；위급기관（OAR）제량분포；궤기도수。결과량조치료계화균능만족림상요구。량조안구、정체、시신경、시교차、시선、뇌간급외이도적평균수조제량상사，차이무통계학의의（P＞0．05）；VMAT조안구、정체、시선급외이도적열점제량소우IMRT조（P＜0．05）。VMAT 조유경소적궤기도수（P＝0．017），조사시간경단。결론 VMAT기술가이만족림상대우다발뇌전이류적대제량방사치료적계화요구；량충방안재파구괄형도、파구균균성무명현차별；VMAT조적안구、정체、시선급외이도열점제량경저；VMAT재축단조사시간방면경구유우세。
Objective To compare volumetric‐modulated arc therapy(VMAT) with intensity‐modulated radiation therapy (IMRT) for brain metastases with regard to the dosimetric character .Methods Sixty patients who were diagnosed with brain me‐tastases were included in this study .The target area received two dose levels using late addition amount technique ,WBRT (30 Gy/10 F) with following addition (20 Gy/10 F) to 59 Gy .For a fair comparison ,VMAT and IMRT treatment plans were respectively designed for every patient with the same dosimetric constraints .Dosimetric comparisons between VMAT and IMRT plans were ana‐lyzed to evaluate :target coverage and homogeneity ,conformity of PTV ;sparing of OARs ;monitor units (MUs) .Results Two treatment plans all reached the treatment need .When compared with IMRT ,there was no significant difference in Dmean of eyeball , len ,optic never ,visual chiasma ,parotid ,brain stem ,and external auditory canal of VMAT (P>0 .05) .The Dmax of eyeball ,len ,pa‐rotid ,and external auditory canal of VMAT were lower than that in IMRT group (P<0 .05) .The VMAT group has the less MUs (P=0 .017) and less treatment time .Conclusion VMAT can reach the big‐dose radiotherapy need on brain metastases clinically . There are no significant diffference between VMAT and IMRT on Dmax ,Dmean ,CI ,and HI .The Dmax of eyeball ,len ,parotid ,and external auditory canal of VMAT were lower than that in IMRT group .The VMAT can reduce the radiotherapy time .