Magnetic resonance spectroscopic imaging 3T and prostate cancer: correlation with transperineal ultrasound guided prostate biopsy.

ABSTRACT

OBJECTIVES: The aim of our study was to correlate the results obtained by 3T Magnetic Resonance Spectroscopic Imaging (MRSI3T) with those obtained by histological examination of samples of the trans-perineal ultrasound-guided prostate biopsy (TPUS-B). METHODS: 34 patients were enrolled in the study. All patients had a clinical suspicion of cancer due to increased PSA and/or positive digital rectal examination. Patients were subjected to an MRSI 3T examination and subsequently to TPUS-B. RESULTS: Of the 22 (22/34) patients who presented abnormalities MRSI at 3T, 9 had a histological diagnosis of Prostate adenocarcinoma. Of the remaining 13 patients, 6 were found to be histologically positive for Benign Prostatic Hypertrophy and 7 Chronic Interstitial Inflammation or High Grade Prostatic Intraepithelial Neoplasia. 12 (12/34) patients found to have no peripheral alterations in their prostate on 3T MRSI, none were positive for ADK or inflammation on histology. The sensitivity, specificity, positive predictive value and negative predictive value were 100%, 48%, 40% and 100% respectively. DISCUSSION: In this study, we correlated the values obtained from 3T MRSI with the results of histologically examined prostate biopsies. Our work shows that 72.8% of the voxels in which there was a change in ratio of Cit/(Cho + Cr), corresponded to areas of prostate tissue disease. Of these, 73.2% were positive for ADK and 26.8% for CII or HG PIN. In literature, it is noted that PCa can be distinguished from areas of benign tissue, in the peripheral zone, on the basis of the values of the ratio Cit/(Cho + Cr) (17), although some benign conditions, such as prostatitis or PINHG, can alter these values (18-19). CONCLUSIONS: In conclusion, the use of MRSI 3T before performing prostate biopsies may represent a valid aid for the urologist in the diagnosis of PCa, allowing them to avoid unnecessary prostate biopsies that may be negative. Furthermore, it would also be possible to reduce the total number of biopsies, thus decreasing patient exposure to the unnecessary risks associated with biopsy.