Neoadjuvant irradiation of extremity soft tissue sarcoma with ions (Extrem-ion): study protocol for a randomized...

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Standard treatment for extremity soft tissue sarcoma involves wide resection and radiotherapy, achieving high local control but debating radiotherapy timing.
• Preoperative radiotherapy may offer reduced late side effects compared to postoperative, despite higher acute wound complication rates.
• Particle therapy, including carbon ions, and hypofractionation show promise for improved tissue sparing, reduced toxicity, and shorter treatment durations.

Purpose of the Study:

• To evaluate the safety and feasibility of hypofractionated, preoperative proton or carbon ion radiotherapy for soft tissue sarcoma of the extremities.
• To assess the potential for reduced toxicity associated with particle therapy in this setting.

Main Methods:

• A prospective, randomized, monocentric phase II trial (Extrem-ion, NCT04946357) involving patients with resectable or marginally resectable soft tissue sarcoma.
• Randomization between neoadjuvant proton or carbon ion radiotherapy (39 Gy RBE in 13 fractions) using active scanning beam technique.
• Primary endpoint: proportion of treatments without wound healing disorder within 120 days post-surgery; secondary endpoints include local control, survival, and quality of life.

Main Results:

• The study is designed to confirm the safety and feasibility of the investigated treatment regimen.
• Results will inform the design of a future phase III trial comparing proton and carbon ion irradiation efficacy.

Conclusions:

• Hypofractionated, preoperative radiotherapy using particle therapy is being investigated for its safety and feasibility in treating soft tissue sarcomas.
• This approach aims to minimize treatment toxicity, with potential for improved outcomes in future comparative trials.