Department of Radiation Oncology, University of Cincinnati and Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219-0757,
Int J Radiat Oncol Biol Phys. 2012 Jun 1;83(2):720-6. doi: 10.1016/j.ijrobp.2011.06.2011. Epub 2011 Nov 19.
To analyze the effect of reduced-dose radiotherapy on local control in children with low-risk rhabdomyosarcoma (RMS) treated in the Children's Oncology Group D9602 study.
Patients with low-risk RMS were nonrandomly assigned to receive radiotherapy doses dependent on the completeness of surgical resection of the primary tumor (clinical group) and the presence of involved regional lymph nodes. After resection, most patients with microscopic residual and uninvolved nodes received 36 Gy, those with involved nodes received 41.4 to 50.4 Gy, and those with orbital primary tumors received 45 Gy. All patients received vincristine and dactinomycin, with cyclophosphamide added for patient subsets with a higher risk of relapse in Intergroup Rhabdomyosarcoma Study Group III and IV studies.
Three hundred forty-two patients were eligible for analysis; 172 received radiotherapy as part of their treatment. The cumulative incidence of local/regional failure was 15% in patients with microscopic involved margins when cyclophosphamide was not part of the treatment regimen and 0% when cyclophosphamide was included. The cumulative incidence of local/regional failure was 14% in patients with orbital tumors. Protocol-specified omission of radiotherapy in girls with Group IIA vaginal tumors (n = 5) resulted in three failures for this group.
In comparison with Intergroup Rhabdomyosarcoma Study Group III and IV results, reduced-dose radiotherapy does not compromise local control for patients with microscopic tumor after surgical resection or with orbital primary tumors when cyclophosphamide is added to the treatment program. Girls with unresected nonbladder genitourinary tumors require radiotherapy for postsurgical residual tumor for optimal local control to be achieved.
分析在儿童肿瘤协作组 D9602 研究中接受低剂量放疗的低危横纹肌肉瘤（RMS）患儿的局部控制效果。
低危 RMS 患儿被非随机分配接受放疗剂量，取决于原发肿瘤手术切除的完全性（临床组）和区域淋巴结受累情况。切除后，大多数有镜下残留和无累及淋巴结的患者接受 36 Gy，有累及淋巴结的患者接受 41.4 至 50.4 Gy，有眼眶原发肿瘤的患者接受 45 Gy。所有患者均接受长春新碱和放线菌素 D 治疗，对于在 Intergroup Rhabdomyosarcoma Study Group III 和 IV 研究中复发风险较高的患者亚组，加用环磷酰胺。
342 例患者符合分析条件；172 例患者接受了放疗。当环磷酰胺不是治疗方案的一部分时，有镜下受累边缘的患者局部/区域失败的累积发生率为 15%，当包括环磷酰胺时则为 0%。有眼眶肿瘤的患者局部/区域失败的累积发生率为 14%。对于接受组 IIA 阴道肿瘤（n = 5）的女孩，根据方案规定省略放疗，导致该组有 3 例失败。
与 Intergroup Rhabdomyosarcoma Study Group III 和 IV 的结果相比，当在治疗方案中加入环磷酰胺时，对于手术后肿瘤有镜下肿瘤或有眼眶原发肿瘤的患者，减少剂量的放疗并不会影响局部控制。对于未切除的非膀胱泌尿生殖系统肿瘤的女孩，为了达到最佳的局部控制效果，需要对手术后的残留肿瘤进行放疗。
