MRI may be used to identify men with elevated PSA levels and prior negative prostate biopsies in whom further biopsy is unnecessary, according to a small Italian study [1].
Elevated serum PSA levels combined with negative biopsy findings frequently present a diagnostic dilemma, with subsequent biopsies being negative in the vast majority of patients, the research group of radiologists and urologists noted.
With this in mind, they aimed to assess whether MRI or combined MRI-MR spectroscopy (MRS) could be used to accurately differentiate patients who would benefit from additional trans-rectal ultrasound-guided biopsies from those in whom further sampling is unnecessary.
The study recruited 54 men with a total PSA of at least 4 ng/ml and one or more prior negative biopsy rounds to undergo combined MRI-MRS and ten-core sampling. Supplementary samples were taken from suspicious sites identified on MRI or MRS.
Prostate cancer was detected in 17 men. All cases had been identified as ‘suspicious’ on MRI, and 15 on MRS. The researchers calculated the sensitivity and specificity of MRI to be 100 and 64.9 per cent, respectively; combining MRS with MRI maintained the same sensitivity whilst lowering the specificity.
The group concluded that “MRI alone might be able to select negative patients in whom further biopsies are unnecessary.”
It elaborated: “The cancer detection rate is higher for patients undergoing MR-guided biopsy compared with the standard core biopsy procedure. There is now evidence that patients in whom a wait and see strategy may be advocated can be selected using MR and selection may be based on the morphological evaluation.”
[1] Value of endorectal MRI and MRS in patients with elevated prostate-specific antigen levels and previous negative biopsies to localize peripheral zone tumours
Clin Radiol 2008; 63: 871-879
