Dr Liu on the Use of PSMA PET to Inform Lymph Node Dissection in Prostate Cancer

Jen-Jane Liu, MD, associate professor, urology, Oregon Health & Science University, discusses how prostate-specific membrane antigen (PSMA) PET imaging may help inform lymph node dissection in the localized disease setting for patients with prostate cancer.

Prostate cancer nomograms are commonly used to determine if a patient would benefit from lymph node dissection, Liu begins. This predictive model is used to assess a patient's current risk according to their individual and tumor characteristics, as well as long-term outcomes following a given treatment. Generally, lymph node dissection is not recommended if the nomogram shows that the risk of detecting metastases for a given patient is between 2% to 5%, she states.

The accurate predication of which patients would experience benefit with lymph node dissectionis vital, as the procedure is associated with additional morbidity and can cause other disease complications, Liu emphasizes. Although nomograms have the advantage of providing individualized information on disease-related risk, their clinical utility can be unclear, and they sometimes lack external validation, Liu notes. Therefore, efforts to develop a more accurate and effective method of identifying patients who do not require lymph node dissection have longbeen unsuccessful, she says.

With the increasing implementation of PSMA PET imaging in clinical practice, its potential to address this unmet need is also being considered, Liu continues. Current research suggests that data obtained from PSMA PET alone is not sufficient for making this decision due to a substantial false negative rate in patients considered for surgery, Liu explains. However, several studies have combined PSMA PET with other imaging modalities such as magnetic resonance imaging, as well as other clinical parameters, Liu notes. These combined approaches may move the needle forward by allowing for a more accurate prediction of patient outcomes with lymph node dissection, Liu concludes.