Phase II Trial of Neoadjuvant Hypofractionated Radiotherapy Versus Conventionally Fractionated Radiotherapy for Soft Tissue Sarcomas

Summary

This research study is designed to find out if radiation therapy treatment prior to surgery is safe and effective to treat soft tissue sarcomas. 30 participants with soft tissue sarcoma will be enrolled and can expect to be on study for up to 5 years.

Detailed description

Standard treatment for soft tissue sarcomas is a combination of radiation therapy and surgery. Radiation therapy is usually done prior to the surgical removal of the tumor. Most commonly, conventionally fractionated radiotherapy is used for soft tissue sarcomas, in which radiation therapy is given over 25 treatments in a time period of approximately 5 weeks. Conventionally fractionated radiotherapy is radiation treatment that is delivered over the course of several days; typically divided into doses that are delivered each weekday over a set number of weeks. Each radiation treatment is called a "dose fraction", thus the name "fractionated". Hypofractionated radiotherapy is a technique in which a higher dose of radiation is given over a fewer number of treatments. Early studies have suggested that hypofractionated radiotherapy will be safe and effective for pre-operative treatment of soft tissue sarcomas. However, because this disease is rare, there are different kinds of soft tissue sarcomas, these tumors can occur anywhere in the body, and conventionally fractionated radiotherapy remains standard, more study is needed to find out if hypofractionated radiotherapy is a safe and effective treatment for this disease. Therefore, the investigators plan to compare patients treated with conventionally fractionated radiotherapy over 25 treatments in a time period of 5 weeks to patients treated with hypofractionated radiotherapy over 5 treatments in a time period of 1-2 weeks. The investigators hypothesize hypofractionated radiotherapy in the pre-operative treatment of soft tissue sarcomas can effectively treat soft tissue sarcomas while minimizing side effects and minimizing the time between diagnosis and surgical resection. Patients with liposarcoma (LPS) or undifferentiated pleomorphic sarcoma (UPS) may receive standard of care pembrolizumab concurrently with radiation therapy at the discretion of their treating medical oncologist. Primary Objective * Evaluate soft tissue sarcoma tumor response to neoadjuvant hypofractionated versus conventionally fractionated radiotherapy. Secondary Objectives * Evaluate soft tissue sarcoma tumor response to neoadjuvant hypofractionated versus conventionally fractionated radiotherapy. * Evaluate acute wound healing complications after neoadjuvant hypofractionated versus conventionally fractionated radiotherapy. * Evaluate late toxicity in patients undergoing neoadjuvant hypofractionated versus conventionally fractionated radiotherapy. * Evaluate local tumor control and progression-free survival after hypofractionated versus conventionally fractionated radiotherapy. Exploratory Objectives * Evaluate surgically resected tissue for markers of tumor cell susceptibility to immune response, immune infiltration, and anti-tumor immune response following neoadjuvant hypofractionated compared to conventionally fractionated radiotherapy * Evaluate quality of life in patients undergoing neoadjuvant hypofractionated versus conventionally fractionated radiotherapy.

Arms & interventions

• RadiationConventional Fractionated

  50 Gy in 25 fractions will be prescribed to cover 95% of the planning tumor volume (PTV). More than 99% of the PTV should receive \> 97% of the prescribed dose. For dose homogeneity, no more than 20% of the PTV will receive ≥ 110% prescription dose.

• RadiationHypofractionated

  27.5 Gy in 5 fractions will be prescribed to cover 95% of the PTV. More than 99% of the PTV should receive \> 97% of the prescribed dose

Outcome measures

Eligibility criteria