Phase II Clinical Trial of Low-intervention Using Hypofractionated Protontherapy in Chordomas and Chondrosarcomas of the Skull Base

What this Trial Is About

Researchers are evaluating the use of hypofractionated proton therapy in treating chordomas and chondrosarcomas located at the base of the skull. These rare, slow-growing tumors tend to recur locally and are challenging to treat due to their proximity to critical structures. This phase II clinical trial aims to gather more scientific evidence on the effectiveness and safety of delivering high-dose proton therapy in fewer sessions compared to conventional longer treatments with photons, while also assessing patient quality of life and dosimetric benefits. The study compares two hypofractionated proton therapy schedules based on tumor size and vascular health: one with 5 treatment sessions (fractions) and another with 27 fractions. For 5 fractions, chordomas receive 37.5 Gy total and chondrosarcomas receive 35 Gy total, both delivered in consecutive sessions. The 27-fraction regimen delivers an integrated boost dose with slightly lower doses per session. Treatment plans use multiple proton beams to precisely target tumors while sparing nearby organs. Patients are assigned to the treatment schedule that best fits their tumor characteristics and safety considerations. Participants will undergo baseline assessments including MRI scans to evaluate tumor size and vascular conditions. Treatment tolerance will be monitored acutely (up to 3 months) and chronically (up to 10 years). Researchers will assess local tumor control using MRI, patient quality of life via questionnaires 3 months after treatment, and dosimetric quality of the proton therapy plans. The study involves close monitoring of potential side effects, especially brain tissue changes, over a long follow-up period to better understand treatment safety and effectiveness.

Hypofractionated Protontherapy in Chordomas and Chondrosarcomas of the Skull Base