Preoperative radiotherapy for extremity soft tissue sarcoma; past, present and future perspectives on dose fractionation regimens and combined modality strategies

Introduction: This critical review aims to summarize published data on limb sparing surgery for extremity soft tissue sarcoma in combination with pre-operative radiotherapy (RT). Methods: This review is based on peer-reviewed publications using a PubMed search on the MeSH headings “soft tissue sarcoma” AND “preoperative radiotherapy”. Titles and abstracts screened for data including “fraction size AND/OR total dose AND/OR overall treatment time”, “chemotherapy”, “targeted agents AND/OR tyrosine kinase inhibitors”, are collated. Reference lists from some articles have been studied to obtain other pertinent articles. Additional abstracts presented at international sarcoma meetings have been included as well as information on relevant clinical trials available at the ClinicalTrials.gov website. Results: Data are presented for the conventional regimen of 50-50.4 Gy in 25-28 fractions in 5-6 of weeks preoperative external beam RT with respect to the regimen's local control probability compared to surgery alone, as well as acute and late toxicities. The rationale and outcome data for hypofractionated and/or reduced dose regimens are discussed. Finally, combination schedules with conventional chemotherapy and/or targeted agents are summarized. Conclusion: Outside the setting of well-designed prospective clinical trials, the conventional 50 Gy in 5-6 week schedule should be considered as standard. However, current and future studies addressing alternative fraction size, total dose, overall treatment time and/or combination with chemotherapy or targeted agents may reveal regimens of equal or increased efficacy with reduced late morbidities.