Chen Changhu, Shu Hui Kuo G, Goldwein Joel W, Womer Richard B, Maity Amit
Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA.
Int J Radiat Oncol Biol Phys. 2003 Apr 1;55(5):1294-9. doi: 10.1016/s0360-3016(02)04290-6.
To assess the influence of radiation volume on outcome in pediatric parameningeal rhabdomyosarcomas (PM-RMSs).
Thirty patients ranging in age from 2 to 18 years (median 6) with PM-RMS were treated at the Hospital of the University of Pennsylvania and the Children's Hospital of Philadelphia between August 1988 and December 1999. The histologic subtypes included embryonal (n = 26), alveolar (n = 3), and undifferentiated (n = 1). Twenty-seven patients had Group III and three had Group IV disease. Twenty-seven patients underwent biopsy only and three subtotal resection. All patients were treated with multiple-agent chemotherapy and external beam radiotherapy. In 8 patients, all of whom had intracranial tumor extension, the tumor and whole brain were treated as the initial volume. In the remaining patients, most of those treated before 1992 were treated to the prechemotherapy (CMT) tumor volume for the entire treatment up to the total dose, which ranged from 45 to 59.4 Gy (median dose 57.9). In contrast, patients treated after 1992 generally received radiation initially to the pre-CMT volume (30.6-40 Gy; median dose 36) followed by a conedown to the post-CMT volume to a final dose of 41.4-55.2 Gy (median 50.4).
With a median follow-up of 6.2 years (range 2.1-13.3), the actuarial 5-year overall survival, progression-free survival, and local control rate for the entire group was 82%, 76%, and 76%, respectively. Seven failures and five deaths have been documented. In univariate analysis, histologic type, tumor size, and age at diagnosis were found to be predictive of overall survival and local control. No statistically significant difference in overall survival or local control was seen between patients who received a conedown to the post-CMT volume (n = 13) and patients in whom the pre-CMT volume was included for the entire treatment (n = 9).
Radiotherapy delivered to children with PM-RMS using a shrinking field technique with a post-CMT volume boost was effective and appears to give results comparable to those of patients in whom the pre-CMT volume was treated for the entire course. The use of such tailored treatment fields is likely to lead to fewer late effects and warrants further investigation.
评估放射治疗体积对小儿颅旁横纹肌肉瘤（PM-RMS）治疗结果的影响。
1988年8月至1999年12月期间，宾夕法尼亚大学医院和费城儿童医院共收治了30例年龄在2至18岁（中位年龄6岁）的PM-RMS患者。组织学亚型包括胚胎型（n = 26）、肺泡型（n = 3）和未分化型（n = 1）。27例患者为Ⅲ组，3例为Ⅳ组疾病。27例患者仅接受活检，3例接受次全切除。所有患者均接受多药化疗和外照射放疗。8例有颅内肿瘤侵犯的患者，将肿瘤和全脑作为初始照射体积。其余患者中，1992年前接受治疗的大多数患者在整个治疗过程中直至总剂量（范围为45至59.4 Gy，中位剂量57.9 Gy）均接受化疗前（CMT）肿瘤体积的照射。相比之下，1992年后接受治疗的患者通常最初接受CMT前体积的照射（30.6 - 40 Gy，中位剂量36 Gy），随后缩野至CMT后体积，最终剂量为41.4 - 55.2 Gy（中位剂量50.4 Gy）。
中位随访6.2年（范围2.1 - 13.3年），全组患者的5年总生存率、无进展生存率和局部控制率分别为82%、76%和76%。已记录到7例复发和5例死亡。单因素分析发现，组织学类型、肿瘤大小和诊断时年龄可预测总生存率和局部控制情况。接受缩野至CMT后体积的患者（n = 13）与整个治疗过程均包括CMT前体积的患者（n = 9）在总生存率或局部控制方面无统计学显著差异。
对PM-RMS患儿采用缩野技术并在CMT后体积进行加量的放疗是有效的，其结果似乎与整个疗程均采用CMT前体积治疗的患者相当。使用这种定制的治疗野可能会减少晚期效应，值得进一步研究。
