Sci‐AM1 Sat ‐ 01: A system for MRI‐guided thermal therapy of prostate disease with transurethral ultrasound heating applicators

An increasing number of prostate cancers are detected at an early stage when the tumour is localised within the gland. Image‐guided transurethral thermal therapy is a promising minimally‐invasive approach to treat targeted regions of the prostate gland while sparing surrounding tissue from unwanted damage. This work describes both a system developed to deliver MRI‐guided transurethral thermal therapy, and the characterisation of multi‐element ultrasound heating applicators. The delivery system includes five independent channels capable of producing up to 50W of RF power. Heating patterns produced by the device can be visualised during treatment using MRI thermometry and software developed to interface with the MR scanner. A fully MRI‐compatible motor has also been developed to rotate the heating applicator during treatment within the scanner. Evaluation of the capability to perform quantitative thermometry during heating with these heating applicators has been performed in a thermal gel material (TGM) developed in our lab with tissue‐mimicking ultrasound and thermal properties. This system has enabled us to validate MRI measurements of temperature distributions with the boundary of thermal coagulation in the TGM. In addition, verification of numerical simulations of heating has been accomplished and the feasibility of using this technology for conformal treatment of the prostate has been addressed.