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.

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Jen-Jane Liu, MD, discusses how prostate-specific membrane antigen PET imaging may help inform lymph node dissection in the localized disease setting for patients with prostate cancer.

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 the benefits of using prostate-specific membrane antigen (PSMA) PET imaging in the localized disease setting for patients with prostate cancer, the differences between PSMA PET and conventional imaging, and future considerations for effectively implementing this diagnostic approach in this population.

PSMA PET imaging can help guide individualized prostate cancer treatment strategies, particularly in patients with high-risk disease, Liu says. Since the standard of care for an increasing number of patients with low-risk prostate cancer has become active surveillance, those with localized disease who are eligible for treatment are often those with high-risk disease, Liu notes. As PSMA PET imaging is more sensitive than conventional imaging, it can identify more sites of metastatic disease than conventional methods, even in patients who are initially believed to have localized disease, Liu explains.

However, using the results of PSMA PET imaging to guide treatment decisions requires caution, Liu says. Choosing treatments based on PSMA PET results does not always lead to better patient outcomes, since the available prostate cancer treatment indications are often based on findings from less accurate conventional imaging, according to Liu. For instance, although choosing to forego local therapy in a patient with metastatic disease was once an acceptable treatment decision based on conventional imaging results, the data informing this approach are not applicable when factoring in PSMA PET results, Liu explains.

Thoughtfully interpreting and implementing PSMA PET results can lead to more nuanced and accurate treatment approaches, Liu notes. For example, if a patient with prostate cancer is planned to receive radiation, but PSMA PET results show lymph node metastases, this treatment consideration may be expanded to include radiation at those metastatic sites as well, provided this amended approach does not cause too much additional toxicity, Liu concludes.

Jen-Jane Liu, MD, discusses the benefits of using prostate-specific membrane antigen PET imaging in the localized disease setting for patients with prostate cancer, the differences between PSMA PET and conventional imaging, and future considerations for effectively implementing this diagnostic approach in this population.

Jen-Jane Liu, MD

Articles

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

Dr Liu on PSMA PET Imaging in Prostate Cancer