PROSARC-2 Phase II Trial of Dose-Escalated Proton Radiotherapy for Inoperable Soft Tissue Sarcoma Multicenter Study Assessing Tumor Control and Biomarkers

What this Trial Is About

Researchers are evaluating if dose-escalated proton radiotherapy can improve local control in patients with inoperable soft tissue sarcomas. This study replaces the standard photon-based radiation with proton therapy, aiming to increase the radiation dose to the tumor without increasing side effects. The study is a single-arm, open-label, multicenter phase II trial conducted in Norway, including 40 patients over three years and following them for up to five years. It also investigates biomarkers in blood and tumor tissue to predict treatment response. Participants will receive proton beam therapy with a prescribed dose of 56 Gray Gy delivered in 16 fractions over 4 weeks, with a possible dose escalation up to 80 Gy in the tumor core. The treatment is given four times per week. All participants will be treated at specific centers in Norway after a careful clinical evaluation by a multidisciplinary team. The study also collects tumor tissue, blood, plasma, and serum samples to support biomarker research. During the study, patients will undergo regular assessments including MRI scans and blood tests to monitor treatment response and side effects. Researchers will measure local progression-free survival at 2 years as the primary outcome, along with secondary outcomes such as overall survival, progression-free survival, tumor response rates, quality of life, and toxicity up to five years after treatment. Participants will need to travel to treatment centers and complete questionnaires as part of the study procedures.

Dose-escalated, Hypofractionated, Definitive Proton Radiotherapy for Patients With Inoperable Soft Tissue Sarcoma.