• Prostate Specific Membrane Antigen (PSMA) based imaging is a breakthrough in diagnostic imaging to better locate prostate cancer tumors for patients with newly diagnosed high risk prostate cancer and recurrence of prostate cancer after treatment.
• PSMA is a protein found on the surface of all prostate cells that can help prostate cancer show up better in imaging.
• PSMA PET works by injecting a radioactive tracer which attaches itself to the PSMA proteins on the prostate cells. Because prostate cancer tumors overexpress these proteins on their surface, physicians are able to pinpoint their location with the tracer.
• PSMA PET/CT imaging can help physicians see the location of prostate cancer growth better than traditional imaging. PSMA PET/CT imaging is a better standard of care because it is more accurate.
• PSMA can help inform the decisions you and your doctor will make regarding your prostate cancer treatment plan
• The University of Tennessee Medical Center is actively involved in PSMA research including PSMA PET-focused clinical trials.
• The Urologic Oncology team at the University of Tennessee Medical Center’s Cancer Institute is here to answer your questions and to provide the highest and most advanced level of care to the people of East Tennessee.

Traditional imaging modalities for prostate cancer including CT, Bone Scan, and MRI have a limited ability to detect small areas of cancer that have spread in men with high risk prostate cancer or metastatic disease.  For this reason, physicians may have a difficult time identifying the full extent of the patient’s prostate cancer burden. This incomplete information can lead to diagnostic challenges and treatment dilemmas. Positron Emission Tomography (PET) imaging is often used in comparable situations with other types of cancer to help clarify how far the disease has spread. Unfortunately, conventional PET imaging is not as helpful diagnosing in men with prostate cancer because common PET radiotracers are weakly metabolized in prostate tissue.

In December 2020, the United States Food and Drug Administration approved Prostate Specific Membrane Antigen (PSMA) based imaging for patients with newly diagnosed high risk prostate cancer and recurrence of prostate cancer after treatment. PSMA is a protein that is found on the surface of all prostate cells and is most strongly expressed in prostate cancer cells. Due to its external location, PSMA is a favorable target for molecular imaging such as PET and drug delivery (termed theranostics). PSMA PET offers the promise of more accurate staging of men who are at risk of having disease outside of the prostate at presentation and can help guide treatment decisions among those men who develop recurrent cancer that would typically be ‘invisible’ with conventional imaging techniques.

PSMA is not only an excellent target for molecular imaging but also offers an accessible target for the delivery of very small doses of focused radiation termed beta particles. Two recent studies investigated the use of ¹⁷⁷Lu-PSMA-617 (LuPSMA) among men with metastatic castrate-resistant prostate cancer (very advanced prostate cancer no longer responding to traditional hormonal therapy and/or chemotherapy). Patients who underwent LuPSMA treatment had better outcomes and fewer side effects compared to men receiving third-line chemotherapy.

These studies received considerable press coverage for good reason as LuPSMA appears very promising for patients with metastatic prostate cancer. However, many questions remain unanswered. The ideal treatment space for use of theranostics like LuPSMA remains undefined. Should PSMA radioligand therapies be used in combination with traditional hormonal therapies? What about prostate cancer cells that do not express or weakly express PSMA? Could PSMA-directed therapy be offered to men who do not have metastatic disease…perhaps men with high-risk localized disease?

A variety of clinical trials are ongoing to help answer these questions. At the University of Tennessee Medical Center, we are actively involved in PSMA research including PSMA PET-focused clinical trials. As always, the Urologic Oncology team at the University of Tennessee Medical Center’s Cancer Institute is here to answer your questions and to provide the highest and most advanced level of care to the people of East Tennessee.