Metal artifact-free MRI-guided re-irradiation for recurrent spinal metastases from thyroid cancer

Soft tissue tumors near metal implants are sometimes difficult to treat with real-time image-guided radiation therapy. Low-field MRI was utilized to clearly delineate the tumor and spinal cord while avoiding metal artifacts, and re-irradiation was performed for recurrent spinal metastases.

A 57-year-old woman with a history of thyroid cancer was referred for re-irradiation for recurrent painful bone metastases in the thoracolumbar spine. She had already undergone conventional radiation therapy followed by stereotactic ablative radiotherapy and multiple fusion surgeries. Since the radiation dose to the spinal cord should have been limited, metal artifact-free low-field MRI-guided re-irradiation was performed with no significant adverse events.

Low-field MRI-guided re-irradiation may be feasible for recurrent spinal metastases, even after metal implants have been placed.