Multi-parametric magnetic resonance imaging: Is active surveillance right for you?

This study evaluated the use of multi-parametric magnetic resonance imagining (MRI) in the selection of prostate cancer patients for active surveillance.

Active surveillance was introduced as a therapeutic strategy to avoid overtreatment of cancer patients with a relatively non-threatening disease. In active surveillance close observation rather than immediate treatment is recommended. The key to the success of active surveillance is the ability to identify cancer patients at sufficiently low risk for cancer progression. Currently, factors such as Gleason score, cancer stage, tumor volume and blood PSA levels are used to predict the likelihood of disease progression. However, even among patients considered ideal candidates for active surveillance, the disease may be more aggressive than anticipated. Multi-parametric MRI (a specialized medical imaging technique) is increasingly being used to identify lesion abnormalities that may indicate high-risk prostate cancer. This study evaluated the use of multi-parametric MRI in determining eligibility for active surveillance.

85 prostate cancer patients underwent a multi-parametric MRI as well as prostate biopsy to determine eligibility for active surveillance. MRI suspicion score, as well as the number of lesions found and lesion density were found to be associated with active surveillance eligibility. A predictive model (referred to as a nomogram: a diagram representing the relationship between three or more variables) was generated to assess multi-parametric MRI results and determine the risk of high risk lesions. The nomogram showed good negative predictive values when compared to active surveillance eligibility according to standard criteria, indicating that the multi-parametric MRI based nomogram can identify low risk patients with high accuracy.

This study concluded that multi-parametric MRI can accurately predict eligibility for active surveillance. These findings have potential to reduce the number of routine biopsies patients must undergo.

Larger studies including assessment of long term outcomes are needed to confirm these results. In addition, prostate lesion MRI suspicion scoring systems are not yet standardized and may make the model difficult to apply uniformly.