MRI appearance of prostate following transrectal HIFU ablation of XXXX .

@entity1 @entity263 @entity39 @entity5 @entity2287
OBJECTIVES: To evaluate the accuracy of @entity2287 -enhanced MRI in gauging the extent of the tissue damage induced by transrectal high intensity focused ultrasound (HIFU) therapy and to assess how well the results obtained with this modality correlate with histological findings (control biopsies). METHODS: Twenty-one @entity1 with biopsy-proven @entity263 (T1-T2-T3a, Nx, M0) who gave informed consent were included in the protocol. They underwent pre- and postoperative (2-5 days after HIFU treatment) MR examinations. Fifteen @entity1 also underwent a follow-up MR examination 1-5 months postoperatively. MR findings were compared with the results of postoperative transrectal biopsy examinations. RESULTS: The prostate volume increased after the HIFU session from 43.9+/-18.6 to 52.1+/-21 cm(3) by day 2 (p<0.001). On fat-saturated @entity2287 -enhanced T1-weighted images, the treated area appeared as a hypointense zone surrounded by a peripheral rim of enhancement in all @entity1 . A positive correlation (r = 0.75) was found between the volume of the hypointense zone measured at days 2-5 (30+/-11 cm(3), 67% of the posttreatment prostate volume) and the theoretical target volume (22+/-5 cm(3), 61% of the initial prostate volume). MRI showed that the anterior part of the base was not reached by the ultrasound beam. The mean volume of the untreated zone (prostate without any MRI modifications) was 8 cm(3) (range, 0.4-36). No correlation was found between the MRI appearance of the treated area and the intensity of the @entity39 or the presence of foci of residual, viable @entity5 . CONCLUSION: @entity2287 -enhanced MRI is an accurate way of determining the extent of tissue damage induced in HIFU ablative therapy, but cannot predict histological results.
