Catherine Roy MD, Presenter: Nothing to Disclose

Seti Tetekpor, Abstract Co-Author: Nothing to Disclose

Benoit Sauer MD, Abstract Co-Author: Nothing to Disclose

Herve Lang, Abstract Co-Author: Nothing to Disclose

Christian Saussine, Abstract Co-Author: Nothing to Disclose

Didier Jacqmin, Abstract Co-Author: Nothing to Disclose

High Intensity focused Ultrasound (HIFU) is a non invasive thermal ablation proposed to cure localized prostate carcinoma. There is no consensus for a reliable way to assess local recurrency for deciding to retreat. The purpose of this prospective study was to compare the usefulness of TRUS with color Doppler (cdTRUS) and Endorectal MRI (erMR) in detecting patterns of recurrence following such therapy.

From October 2003 to January 2005, 25 patients who had received HIFU treatment underwent erMR examination with an interval of 10 days before cdTRUS-guided biopsy. ErMR examinations were performed on a 1T MR unit using 3 planes T2w FSE (TR/TE : 3925/120ms, tf :14, 4 mm) and axial dynamic contrast SE T1w (TR/TE : 412/7, tf : 5, 4 mm, 18s, 8 repeated sequences). The interval between treatment and imaging ranged from 6 to 12 months. PSA levels ranged between 2 to 5 ng/mL. An area of low intensity and/or increased signal intensity on injected erMR (versus detection of vascularization on color Doppler) in the remaining peripheral zone was considered as positive. Systematic sextant biopsy with additional cores in area suspected on imaging modalities were realized. Images were correlated with pathologic results provided with a thorough labelled samples according to their location.

At pathology, 9 patients had recurrence. Negative biopsy results provided necrotic tissues. On cdTRUS, all cases presented heterogeneous pattern with diffuse hyperechoic spots in addition to multiple localized area of vascularisation. 3 patients had clearly hypoechoic hypervascular irregular area suspicious for recurrence. Two were positive. On erMRI, 8 patients presented abnormalities with hypointense signal on T2w and intense abnormal localized enhancement on injected sequence with a wash-in value from 15 - 35 l/s (mean: 22,8 l/s). Among them 7 patients had positive results on biopsies (Se : 77%). Only 4 cases had the same location as diagnosed as the initial tumor

ErMRI with injected sequence is the most useful examination to detect recurrence after HIFU treatment. None imaging technique is accurate enough to avoid TRUS biopsy to prove recurrency but ErMRI must be used to localize samples.

Roy, C, Tetekpor, S, Sauer, B, Lang, H, Saussine, C, Jacqmin, D, Role of Imaging in Assessing Recurrence after High Intensity Focused Ultrasound (HIFU) Treatment for Prostate Carcinoma: Prospective Study with Pathologic Correlation.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4410546.html