Primary Outcome Measures:
- Number of Adverse Events [ Designated as safety issue: Yes ]
This study will be performed in two phases. In the first phase, feasibility will be established using the primary objectives set below. The second part will begin no earlier than 30 days after the last patient in the initial phase has completed treatment and once safety and feasibility has been verified.
The primary objective of this study is feasibility. The study will be deemed infeasible if 10% or more of patients experience one of the following:
- Patient cannot be given treatment because anatomy is such that a dosimetrically satisfactory treatment plan cannot be devised (95% of planning target volume covered by 95% of the dose).
- Patient is unable to tolerate more than 25% of treatments (for any reasonable to set patient up within acceptable limits of tolerance, patient unable to tolerate treatment position or immobilization for duration of treatment) using proton radiotherapy. Note: this end-point is proton-therapy specific, and indicates feasibility of proton as opposed to photon radiotherapy. For example, if the proton-specific patient immobilization/positioning is not well tolerated or extra time in the treatment position is too long or uncomfortable, protons delivered per protocol would be deemed not feasible compared to photons. Any treatments that cannot be delivered with protons will be delivered using photons, so that the patient receives the prescribed tumor dose.
- Patient is unable to complete all of his/her treatments within 10 days of estimated date of treatment completion or requires a treatment break greater than 5 days. Additionally, no greater than 33% of patients experience a significant toxicity.
Primary Objectives for second phase of study are:
- The primary objective of Phase II in the pre-operative group will be to evaluate the wound complication rate of pre-operative proton radiotherapy in patients with STS of the lower extremity.
- The primary objective of Phase II in the post-operative group will be to evaluate the functional outcome (e.g., fibrosis, joint stiffness, edema) at two years after post-operative proton radiotherapy in patients with STS of the lower extremity.
Secondary Objectives for both phases of study are:
- To assess the local control rate, progression-free survival and overall survival of proton radiotherapy for STS of the extremity.
- To determine the acute and late toxicities of proton radiotherapy to the extremities.
- To monitor for effects of proton treatment on tumor and normal tissues using radiographic imaging (both cohorts) or ex-vivo analysis of tissue samples (pre-operative cohort only).
- To examine the relationship between pre-treatment hypoxia as determined by F18-EF5 scanning and treatment outcome.