[MR detection of local prostate cancer recurrence after transrectal high-intensity focused US treatment: preliminary results].
OBJECTIVE
To assess T2W and dynamic: contrast-enhanced (DCE) MR imaging in the detection of local tumor recurrence after transrectal high-intensity focused US (HIFU) treatment.


METHODS
Fifteen patients treated by HIFU for prostate cancer were referred for MR due to biological evidence of tumor recurrence. Axial, sagittal and coronal T2W images and DCE images (12 3-mm thick axial images, temporal resolution: 15 seconds) were obtained first. Transrectal biopsies were then obtained under US guidance. MR findings were compared to biopsy results for 10 prostate sectors.


RESULTS
Biopsies demonstrated tumor recurrence in 13/15 patients (23/108 sectors). On T2W images, the treated prostate tissue was diffusely hypointense which interfered with interpretation. Three patients (5 sectors) had suspicious areas of T2W signal abnormality and 15 patients (29 sectors) had suspicious areas on DCE scans. An analysis per sector for T2W and DCE imaging showed sensitivity, specificity, positive predictive and negative predictive values respectively of 0.13, 0.98, 0.6 and 0.81 and 0.70, 0.85, 0.55 and 0.91. DCE MR was strongly predictive of positive biopsy results (Odds ratio: 12.8 (95% confidence interval: 4.4-37.3)) whereas T2W imaging was not (Odds ratio: 4.0 (95% confidence interval: 0.5-30)).


CONCLUSIONS
MR, especially DCE MR, is promising for the detection and localization of local prostate cancer recurrence after transrectal HIFU treatment.
Hospices Civils de Lyon, Département d'Imagerie Urinaire et Vasculaire, Hôpital Edouard Herriot, 5, place d'Arsonval, 69437 Lyon Cedex 03.
A
A
Ben Cheikh
N
N
Girouin
P
P
Ryon-Taponnier
F
F
Mège-Lechevallier
A
A
Gelet
J Y
JY
Chapelon
D
D
Lyonnet
O
O
Rouvière
D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D003287:Contrast Media; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional / Q000379:methods; D036761:Ultrasound, High-Intensity Focused, Transrectal
D003287:Contrast Media; D017430:Prostate-Specific Antigen