Using magnetic resonance imaging on men with low-risk prostate cancer can help determine if they are good candidates for active surveillance, according to a study published last week in the the Journal of Urology.
Researchers from the department of radiology at Memorial Sloan-Kettering Cancer Center in New York evaluated 388 patients who received an initial biopsy between 1999 and 2010, had a Gleason score (a measure of the cancer's aggressiveness) of 6 or less, and then underwent an endorectal MRI before undergoing a confirmatory biopsy.
"Among patients initially diagnosed with clinically low risk prostate cancer, those with tumors not clearly visualized on MRI were significantly more likely to demonstrate low risk features when a confirmatory biopsy was performed, while patients with tumors clearly visualized on MRI were significantly more likely to have their disease status upgraded on confirmatory biopsy," lead investigator Hebert Alberto Vargas of Sloan-Kettering's department of radiology said in an announcement.
The MRI studies were interpreted by three radiologists with different levels of experience with MRI prostate examinations. They assigned scores from 1 to 5 for the presence of a tumor on an MRI, 1 meaning no tumor and 5 meaning a definite tumor.
Upon confirmatory biopsy, Gleason scores were upgraded in 20 percent of the cases. Patients with high MRI scores were more likely to have their disease upgraded, while low scores were associated with low-risk prostate cancer. Agreement on the MRI scores was greater between the more experienced readers.
"These results suggest that MRI of the prostate, if read by radiologists with appropriate training and experience, could help determine active surveillance eligibility and obviate the need for confirmatory biopsy in substantial numbers of patients," Vargas said.