MR Compatible Phased Array HIFU Transducer for Localized Prostate Cancer Treatment; in Vitro Validation

Lorena PETRUSCA¹, Rares SALOMIR¹, Emmanuel BLANC², Lucie BRASSET², Francois COTTON³, Jean-Yves CHAPELON¹

High Intensity Focused Ultrasound (HIFU) under MRI guidance represents a minimally invasive approach for localized prostate cancer treatment. In our in-vitro study, an MR-compatible multi-element endorectal HIFU device capable of focusing the beam at different depths in the tissue is being investigated. Fast MR thermometry was made in 2 orthogonal planes simultaneously for different sonication sequences chosen based on numerical simulations: elementary lesions, lines, slices and volumes. Temperature and thermal dose maps obtained showed that a homogenous lethal dose was induced in the desired shape. Dynamic focusing strategy permits to treat patients with more complex anatomy: smaller or larger prostate.