A Phase II Trial of Preoperative Proton Therapy in Soft-tissue Sarcomas of the Extremities and Body Wall

Data support preoperative radiotherapy as one of the standard options in the management of large or high-grade extremity soft tissue sarcomas (STS). The advantages of preoperative radiotherapy are lower doses and smaller radiation volumes; these may be used to effect improvement of long-term side effects and extremity function. Another potential advantage is assisting surgery through tumor shrinkage and reduction of tumor cell seeding. The disadvantage of preoperative radiation is the higher likelihood of postoperative wound complications, but in a prospective phase III trial these complications were found to be generally temporary and without significant effect on long term function. Combined conservative surgery and radiotherapy has shown to achieve excellent local control in sarcoma patients following margin-negative surgery, but late radiation morbidity and reduced quality of life may result from adjuvant radiation. The dosimetric advantage of proton radiotherapy may translate into reduced acute and late effects due to improved normal-tissue sparing in the treatment of extremity and truncal STS. However, these potential advantages need to be validated in clinical trials. The investigators propose a phase II study to evaluate the effect of preoperative proton radiotherapy on the reduction of late radiation morbidity, patterns of failure, and impact of late radiation morbidity on general quality of life (QOL).