Helical Tomotherapy for Brain Metastases: Dosimetric Evaluation of Treatment Plans and Early Clinical Results
Helical Tomotherapy for Brain Metastases: Dosimetric Evaluation of Treatment Plans and Early Clinical Results
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DOI：
10.1177/153303460800700602
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发表时间：
2008-12-01
影响因子：
2.8
通讯作者：
Shibamoto, Yuta
中科院分区：
文献类型：
--
作者：
Tomita, Natsuo;Kodaira, Takeshi;Shibamoto, Yuta
本研究的目的是评估使用螺旋断层调强放射治疗（HT）治疗脑转移瘤的可行性和治疗计划。23例1 ~ 4个脑转移瘤患者接受HT治疗。结合全脑放疗（同步计划），转移性病灶和全脑分别接受50戈伊和30戈伊治疗，分10次，同时采用综合加强技术。在仅接受脑转移瘤治疗的患者中（病灶计划），转移性病灶接受35或37.5戈伊分5次治疗。治疗计划进行了比较的构象数（CN）和均匀性指数（HI），并在这些指标之间的差异，同时和重点计划进行了检查学生的t检验。分别有7名和16名患者接受了同步计划和焦点计划治疗。对于同步计划，CN和HI值的平均+/- SD分别为0.75 +/- 0.13和0.063 +/- 0.042，对于焦点计划，CN和HI值的平均+/- SD分别为0.73 +/- 0.12和0.052 +/- 0.023。两个计划之间的CN和HI没有显著差异。13例随访影像学患者的缓解率约为90%，1年时的局部控制率为69%。1例巨大肿瘤（34.0 cc）且WHO体能状态3级的患者接受焦点计划治疗后出现重度头痛，需要延长治疗时间，并在治疗完成后8天死亡。恶化的确切原因尚不确定，因为未对该患者进行放射学检查。在长达20个月的随访期间，未观察到晚期并发症。HT是治疗脑转移瘤的可行的非侵入性技术，并且在剂量一致性和均匀性方面实现了高准确性。
The purpose of this study was to evaluate the feasibility and treatment plans of intensity-modulated radiation therapy using helical tomotherapy (HT) for brain metastases. Twenty-three patients with 1 to 4 brain metastases were treated with HT. In combination with whole-brain radiotherapy (simultaneous plans), metastatic lesions, and the whole brain were treated with 50 Gy and 30 Gy, respectively, in 10 fractions, with a simultaneous integrated boost technique. In patients treated for brain metastases alone (focal plans), metastatic lesions were treated with 35 or 37.5 Gy in 5 fractions. The treatment plans were compared regarding the conformation number (CN) and homogeneity index (HI), and differences in these indexes between simultaneous and focal plans were examined by Student's t-test. Seven and 16 patients were treated with simultaneous plans and focal plans, respectively. The mean +/- SD of CN and HI values were 0.75 +/- 0.13 and 0.063 +/- 0.042, respectively, for simultaneous plans, and 0.73 +/- 0.12 and 0.052 +/- 0.023, respectively, for focal plans. The CN and HI between the two plans were not significantly different. Response rates in 13 patients with follow-up imaging were approximately 90% for both plans and the local control rate at 1 year was 69%. One patient with a huge tumor (34.0 cc) and WHO performance status 3 treated with focal plans experienced severe headache, requiring prolongation of the treatment time, and died at 8 days after completion of treatment. The exact cause of deterioration was uncertain as no radiological investigation was performed in this patient. No late complications were observed during follow-up periods up to 20 months. HT is a viable non-invasive technique for treatment of brain metastases and achieves high accuracy in terms of dose conformity and homogeneity.