ORLANDO, FL, USA (UroToday.com) - Peter L Choyke, MD, National Cancer Institute, Bethesda, MA, spoke about active surveillance and a protocol for multiparametric (MP) MRI.
Currently, monitoring prostate cancer patients with active surveillance includes annual PSA monitoring and periodic rebiopsy. The PSA rise unrelated to cancer (from benign prostatic hyperplasia and prostatitis) complicates the progression of low-grade tumors under surveillance. Doing blind biopsies may provide inconsistent information, contributing to the uncertainty of disease progression. In contrast, the multiparametric (MP) MRI of the prostate is emerging as a strong tool to assess the stages of disease. Originally developed in the early 1990s, MP MRI has been primarily used to stage the disease prior to surgery. MP MRI studies have demonstrated a strong efficacy for identifying tumors larger than 0.5 cm in diameter and Gleason score 7 or higher. Dr. Choyke emphasized, "In no way does MP MRI substitute for a biopsy, but it can effectively be used to identify suspicious lesions." At NCI, Choyke and colleagues have a protocol for annual prostate MRI, "Patients have their annual PSA and MP MRI and if this data is approximately stable, the patient can elect to be rebiopsied or followed for an additional year. If PSA rises, the MRI changes, or both events occur, a repeat MRI-US biopsy is recommended."
To date, the expense of MP MRI is high and access to this imaging technology is limited at the local level, however it is often available at tertiary care and academic cancer centers. The disposable endorectal coil used in MP MRI contributes to the overall cost and time for procedure as well as some patient discomfort. Dr. Choyke concluded by looking forward to the day when image-guided biospies are perfected and provide genomic characteristics of the cancer, improving the predictive power for biologic aggressiveness as well as better identification of candidates for active surveillance.
Written by Karen Roberts, medical editor for UroToday.com
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