Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.
Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, Munich, Germany.
Radiat Oncol. 2019 Jan 9;14(1):2. doi: 10.1186/s13014-019-1207-2.
Advanced radiotherapy (RT) techniques allow normal tissue to be spared in patients with extremity soft tissue sarcoma (STS). This work aims to evaluate toxicity and outcome after neoadjuvant image-guided radiotherapy (IGRT) as helical intensity modulated radiotherapy (IMRT) with reduced margins based on MRI-based target definition in patients with STS.
Between 2010 to 2014, 41 patients with extremity STS were treated with IGRT delivered as helical IMRT on a tomotherapy machine. The tumor site was in the upper extremity in 6 patients (15%) and lower extremity in 35 patients (85%). Reduced margins of 2.5 cm in longitudinal direction and 1.0 cm in axial direction were used to expand the MRI-defined gross tumor volume, including peritumoral edema, to the clinical target volume. An additional margin of 5 mm was added to receive the planning target volume. The full total dose of 50 Gy in 2 Gy fractions was sucessfully applied in 40 patients. Two patients received chemotherapy instead of surgery due to systemic progression. All patients were included into a strict follow-up program and were seen interdisciplinarily by the Departments of Orthopaedic Surgery and Radiation Oncology.
Thirty eight patients that received total RT total dose and subsequent resection were analyzed for outcome. After a median follow-up of 38.5 months cumulative OS, local PFS and systemic PFS at 2 years were determined at 78.2, 85.2 and 54.5%, respectively. Two of 6 local recurrences were proximal marginal misses. Negative resection margins were achieved in 84% of patients. The rate of major wound complications was comparable to previous IMRT studies with 36.8%. RT was overall tolerable with low toxicity rates.
IMRT-IGRT offers neoadjuvant treatment for extremity STS with reduced safety margins and thus low toxicity rates. Wound complication rates were comparable to previously reported frequencies. Two reported marginal misses suggest a word of caution for reduction of longitudinal safety margins.
先进的放疗（RT）技术允许在肢体软组织肉瘤（STS）患者中保留正常组织。本研究旨在评估基于 MRI 靶区定义的新辅助图像引导放疗（IGRT）螺旋调强放疗（IMRT）后减少边缘后，STS 患者的毒性和结果。
2010 年至 2014 年，41 例肢体 STS 患者接受了 IGRT 治疗，采用 Tomotherapy 机器进行螺旋调强放疗。肿瘤部位在上肢 6 例（15%），下肢 35 例（85%）。使用 2.5cm 的纵向和 1.0cm 的轴向减少边缘来扩大 MRI 定义的大体肿瘤体积，包括肿瘤周围水肿，以获得临床靶区。另外增加 5mm 的边缘以获得计划靶区。40 例患者成功应用 50Gy/2Gy 全剂量。由于全身进展，2 例患者接受化疗而不是手术。所有患者均纳入严格随访计划，并由矫形外科和放射肿瘤科进行跨学科随访。
对接受全 RT 总剂量和随后切除的 38 例患者进行了生存分析。中位随访 38.5 个月后，2 年的总生存率、局部无进展生存率和全身无进展生存率分别为 78.2%、85.2%和 54.5%。2 例局部复发为近端边缘漏诊。84%的患者获得了阴性切缘。主要伤口并发症发生率与之前的 IMRT 研究相似，为 36.8%。RT 总体耐受，毒性反应率低。
IMRT-IGRT 为肢体 STS 提供了新辅助治疗，减少了安全边缘，因此毒性反应率低。伤口并发症发生率与以前报道的频率相似。2 例报告的边缘漏诊提示应谨慎减少纵向安全边缘。
