CAJ | 학술논문

目的初步观察局限期SCLC化放疗后HT的PCI对海马回区保护照射后的临床反应,并与IMRT、VMAT计划剂量分布进行比较.方法 2014年4-6月,6例局限期SCLC化放疗后达CR患者1个月内脑核磁排除脑转移后接受保护海马回区HT的PCI.将CT定位图像与脑核磁图像进行融合,在融合图像上勾画出海马回,外扩3 mm边界形成减量区域.HT、IMRT、VMAT处方剂量均为95％PTV 25 Gy分10次.评价HT的临床疗效、不良反应、认知功能及脑转移情况,比较3种计划靶区、海马回区剂量分布.结果观察期内l例腹壁及腹腔淋巴结转移、1例局部复发,无脑转移.1+2级头痛、头晕、脱发反应分别为3+1、3+1、4+2例,复诊MMSE平均得分与疗前相近(29.2、29.3、29.7分,P=0.083、0.317、0.157).IMRT、VMAT计划的海马回区Dmean分别为16.85、17.59Gy.HT计划可将海马回区Dmean降至5.26 Gy、外扩减量区降至6.21Gy,处方剂量分别比IMRT、VMAT的降低79％、71％.HT平均处方剂量覆盖率为94.48％.结论应用HT保护海马回区PCI达到了理想剂量分布及较好靶区覆盖度,患者不良反应未增加,认知功能变化尚需延长观察时间及扩大病例进一步研究.
목적 초보관찰국한기SCLC화방료후HT적PCI대해마회구보호조사후적림상반응,병여IMRT、VMAT계화제량분포진행비교.방법 2014년4-6월,6례국한기SCLC화방료후체CR환자1개월내뇌핵자배제뇌전이후접수보호해마회구HT적PCI.장CT정위도상여뇌핵자도상진행융합,재융합도상상구화출해마회,외확3 mm변계형성감량구역.HT、IMRT、VMAT처방제량균위95％PTV 25 Gy분10차.평개HT적림상료효、불량반응、인지공능급뇌전이정황,비교3충계화파구、해마회구제량분포.결과 관찰기내l례복벽급복강림파결전이、1례국부복발,무뇌전이.1+2급두통、두훈、탈발반응분별위3+1、3+1、4+2례,복진MMSE평균득분여료전상근(29.2、29.3、29.7분,P=0.083、0.317、0.157).IMRT、VMAT계화적해마회구Dmean분별위16.85、17.59Gy.HT계화가장해마회구Dmean강지5.26 Gy、외확감량구강지6.21Gy,처방제량분별비IMRT、VMAT적강저79％、71％.HT평균처방제량복개솔위94.48％.결론 응용HT보호해마회구PCI체도료이상제량분포급교호파구복개도,환자불량반응미증가,인지공능변화상수연장관찰시간급확대병례진일보연구.
Objective To preliminarily observe the clinical efficacy of hippocampal-sparing prophylactic cranial irradiation (HS-PCI) using helical tomotherapy (HT) in patients with limited-stage small-cell lung cancer (LS-SCLC) after chemoradiotherapy,and compare HT with intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in dose distribution.Methods From April to June,2014,six patients with LS-SCLC who had achieved a complete remission after chemoradiotherapy were assigned to HS-PCI using HT within a month after brain metastasis was ruled out using brain magnetic resonance imaging (MRI).After fusing CT images and MRI images,the hippocampus was contoured in the fusion images and hippocampal avoidance regions were created using a volumetric expansion of 3 mm around the hippocampus.A dose of 25 Gy in 10 fractions to 95％ of planning target volume (PTV) was prescribed in HT,IMRT,and VMAT.The clinical efficacy,adverse reactions,neurocognitive function,and brain metastasis were evaluated for HT.The dose distribution in PTV and hippocampus were compared between HT,IMRT,and VMAT.Results There were one patient with abdominal wall and abdominal lymph node metastases,one patient with local recurrence,and no patient with brain metastasis during the observation period.The numbers of patients with grade 1 and grade 2 headache,dizziness,and hair loss reactions were 3 and 1,3 and 1,and 4 and 2,respectively.There were no significant differences in the average score of the Mini-Mental State Examination before treatment and at 3 and 6 months after treatment (29.7,29.2,and 29.3 ; P =0.083,0.317,and 0.157).The mean dose to the hippocampus was 16.85 Gy for IMRT and 17.59 Gy for VMAT.For HT,the mean doses to the hippocampus and avoidance regions were reduced to 5.26 Gy and 6.21 Gy,respectively.The prescribed dose for HT was reduced by 79％ and 71％ compared with IMRT and VMAT,respectively.The average coverage rate of the prescribed dose was 94.48％ for HT.Conclusions HT achieves promising dose distribution and target coverage in sparing of the hippocampus.Moreover,HT dose not increase the incidence of adverse reactions.The change in neurocognitive function needs to be further studied with longterm observation and large-scale sampling.