The First Report of Utilizing Low-Field MRI-Guided Radiation Therapy in a Patient with a Cochlear Implant

Our first-in-human case demonstrates the safety and feasibility of using MR-guided radiotherapy (MRgRT) for a patient with a cochlear implant on a 0.35 T MR Linac. A patient with an unresectable intrahepatic cholangiocarcinoma was treated to 50 Gy in 5 daily fractions using a stereotactic MR-guided radiotherapy (SMART) technique on a 0.35 T MR Linac. While the cochlear implant could have been surgically removed prior to MRI, we decided to avoid this radical approach and instead developed a protocol for protecting the implant. For each MR-guided session, the internal magnet within the cochlear implant was protected using a coil cover and compression head wrap. Lessons learned include the need for an MR safety clearance workflow, consent for off-label device scanning at 0.35 T, non-verbal communication approach for breath-hold compliance, and staff training for head wrapping to immobilize implant.