Kubicek Gregory J, LaCouture Tamara, Kaden Maureen, Kim Tae Won, Lerman Nati, Khrizman Polina, Patel Ashish, Xu Qianyi, Lackman Richard
Departments of Radiation Oncology.
Orthopedic Surgery.
Am J Clin Oncol. 2018 Jan;41(1):86-89. doi: 10.1097/COC.0000000000000236.
Preoperative radiation followed by surgical resection is a standard treatment for soft tissue sarcomas (STSs). The conventional method of radiation is 5 weeks to approximately 50 Gy. We report on our initial experience and phase II single-arm study assessing 5 fractions of stereotactic body radiotherapy (SBRT), followed by surgical resection for STS.
Thirteen patients and 14 tumors were treated with preoperative SBRT; tumors were mostly poorly differentiated (5) or myxoid (5) and were located on the leg (10), arm (2) or groin (2). The median tumor size in greatest dimension was 7.6 cm (maximum 16 cm). Twelve patients received 35 Gy in 5 fractions; for 2 deeper tumors the dose was 40 Gy in 5 fractions. Ten patients were administered 0.5 cm bolus to improve the dose. Gross tumor volume was expanded 0.5 cm radially and 3 cm along the tissue plane. Treatment was to an isodose line (median 81%) and was delivered every other day. Maximum dose to the skin was 46 Gy (median 41 Gy).
The median follow-up period was 279 days. Surgical resection occurred a median of 37 days after completion of SBRT. Four patients had acute toxicity consisting of 2 grade 2 and 2 grade 3 skin reactions; all cases of skin toxicity resolved by the time of surgery. Percent tumor necrosis ranged from 10% to 95% (median 60%). All patients had negative margins. Planned vacuum-assisted wound closure was used in 4 patients; there were no other major wound complications. There was 1 local recurrence and 7 distant recurrences.
This is the initial experience of radiosurgery for preoperative treatment of STSs. We have found this to be well tolerated, convenient for the patients, and a much shorter treatment course, allowing patients to undergo surgery and subsequent chemotherapy quicker. Surgical complications and control rates are satisfactory. The initial results are encouraging for further investigation.
术前放疗后行手术切除是软组织肉瘤（STS）的标准治疗方法。传统放疗方法为5周给予约50 Gy剂量。我们报告了我们的初步经验以及一项II期单臂研究，该研究评估了立体定向体部放疗（SBRT）5次分割，随后对STS进行手术切除。
13例患者和14个肿瘤接受了术前SBRT治疗；肿瘤大多为低分化（5个）或黏液样（5个），位于腿部（10个）、手臂（2个）或腹股沟（2个）。肿瘤最大径的中位数为7.6 cm（最大16 cm）。12例患者接受5次分割共35 Gy剂量；对于2个较深的肿瘤，剂量为5次分割共40 Gy。10例患者给予0.5 cm厚的填充物以提高剂量。大体肿瘤体积在径向扩展0.5 cm，沿组织平面扩展3 cm。治疗至等剂量线（中位数81%），每隔一天进行一次。皮肤的最大剂量为46 Gy（中位数41 Gy）。
中位随访期为279天。手术切除在SBRT完成后的中位数为37天进行。4例患者出现急性毒性反应，包括2例2级和2例3级皮肤反应；所有皮肤毒性反应在手术时均已消退。肿瘤坏死百分比范围为10%至95%（中位数60%）。所有患者切缘均为阴性。4例患者采用了计划中的负压辅助伤口闭合；无其他重大伤口并发症。有1例局部复发和7例远处复发。
这是术前治疗STS的放射外科手术的初步经验。我们发现这种方法耐受性良好，对患者方便，且治疗疗程短得多，使患者能够更快地接受手术及后续化疗。手术并发症和控制率令人满意。初步结果令人鼓舞，值得进一步研究。
