Donaldson Sarah S
Department of Radiation Oncology, Stanford University Medical Center, Stanford, California 94305-5847, USA.
Pediatr Blood Cancer. 2004 May;42(5):471-6. doi: 10.1002/pbc.10472.
The outcome of children and adolescents with Ewing sarcoma is impacted by many prognostic factors and often measured by estimates of: event-free, relapse-free, disease-free, or overall survival. However, the preferred assessment following radiation therapy is local control.
A review of large group experiences over the past several decades was undertaken to assess the optimal radiation dose and volume for patients with localized, osseous Ewing sarcoma. New approaches and techniques to improve local control were also investigated.
With multidisciplinary therapy, 5-year overall local control rates range from 58 to 93%. Following definitive irradiation, they are 53-86%. Recommended radiation therapy doses are 55.8-60.0 Gy. In the postoperative setting, gross disease requires 55.8 Gy; microscopic disease requires 45 Gy. Altered fractionation schemes have not improved local control. The appropriate irradiated volume is an involved field to the pretreatment tumor volume plus 2.0-2.5 cm margin, followed by a boost to the post-induction chemotherapy tumor volume with margin. Good radiation quality control with central review improves local control. Use of an involved radiation field requires accuracy in defining tumor volume. Techniques to improve local control include risk-adapted multidisciplinary therapy, intraoperative boost radiation, and high radiation doses as delivered by 3-dimensional conformal radiation. Intensity modulated and proton beam radiotherapy may offer an advantage at special sites.
Innovative uses of radiation in the multidisciplinary setting will continue to provide excellent local control, improved function, and quality of life for young patients with localized Ewing sarcoma of bone.
尤因肉瘤患儿和青少年的预后受多种预后因素影响，通常通过无事件生存期、无复发生存期、无病生存期或总生存期等评估指标来衡量。然而，放疗后的首选评估指标是局部控制。
回顾过去几十年的大量病例经验，以评估局限性骨尤因肉瘤患者的最佳放疗剂量和体积。还研究了改善局部控制的新方法和技术。
采用多学科治疗，5年总体局部控制率为58%至93%。根治性放疗后，局部控制率为53%至86%。推荐的放疗剂量为55.8至60.0 Gy。在术后情况下，大体肿瘤病灶需要55.8 Gy；微小病灶需要45 Gy。改变分割方案并未改善局部控制。合适的照射体积是在预处理肿瘤体积周围外放2.0至2.5 cm的受累野，随后对诱导化疗后的肿瘤体积外放边缘进行推量照射。通过中心审核进行良好的放疗质量控制可提高局部控制率。使用受累放疗野需要准确界定肿瘤体积。改善局部控制的技术包括风险适应性多学科治疗、术中推量放疗以及三维适形放疗所提供的高剂量放疗。调强放疗和质子束放疗在特殊部位可能具有优势。
在多学科治疗中创新性地使用放疗，将继续为局限性骨尤因肉瘤的年轻患者提供出色的局部控制、改善功能和生活质量。
