Mild hyperthermia induced by MRgHIFU as an adjuvant to radiation therapy in bone metastases: preliminary results of a phase I study

Motivation: Mild hyperthermia (HT) induced by magnetic resonance-guided focused ultrasound (MRgHIFU) before radiation therapy (RT) could act as adjuvant in pain relief for bone metastasis. Goal(s): This study aims to evaluate the feasibility and safety of MRgHIFU procedure in one patient with a posterior right acetabulumApproach: The target temperature elevation was 6°C. The targeting and temperature monitoring in near real-time were performed by MRI. Results: The temperature elevation lasting 30-minutes was 6.01°C on average in bone metastasis. The MR-guidance allowed a safe and successful procedure without adverse events. The 25-minutes between HT end point and RT demonstrated the technical feasibility of the procedure. Impact: This study is a first step to demonstrate MRgHIFU hyperthermia adjuvant to palliative radiotherapy of bone metastases. The non-invasive, safe and accurate use of focused ultrasound to sensitize tumors opens the way to more efficient application of the radiation dose.