Dr Koo on Challenges With PSMA PET in Prostate Cancer

Phillip J. Koo, MD, chief, Diagnostic Imaging, Banner MD Anderson Cancer Center, discusses the utility of next-generation imaging in prostate cancer, highlighting the use of prostate-specific membrane antigen (PSMA) PET imaging in this patient population.

Although PSMA PET imaging is an established standard in the prostate cancer field, when considering the use of PSMA PET imaging compared with conventional techniques, several challenges arise, Koo begins, adding that although some medical practices may possess considerable experience with PSMA PET, others may lack exposure to it. Even among seasoned practitioners, there remains a continuous learning curve with PSMA PET due to the discovery of atypical disease distribution patterns that may not have been encountered previously, Koo explains. Particularly, discussions often revolve around interpreting findings, such as solitary rib or pelvic lesions, which pose diagnostic dilemmas as they may or may not signify metastatic disease, and biopsy confirmation may not always be feasible, he adds.

PSMA PET is undeniably a valuable tool in prostate cancer imaging, yet exercising caution in its application is paramount, Koo expands. Overreliance on PSMA PET, especially across all clinical scenarios or for immediate treatment response assessment, may not necessarily yield optimal outcomes, according to Koo. Instead, a judicious approach is warranted, deploying the technology where its efficacy is most pronounced and progressively expanding its use from there, he reports, adding that adherence to established guidelines outlined by various medical societies is imperative to ensure appropriate and effective use.

In defining the role of next-generation imaging in prostate cancer, PSMA PET stands out as a pivotal advancement, characterized by its molecular targeting capabilities, Koo continues. Prostate cancer cells typically exhibit heightened PSMA expression, rendering PSMA PET highly accurate and sensitive, particularly in detecting disease at lower prostate-specific antigen levels, he notes. This heightened accuracy and improved detection ability represent significant advancements over previous imaging modalities, offering clinicians deeper insights into patients' disease statuses and facilitating more informed treatment decisions, Koo concludes.

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Phillip J. Koo, MD, discusses the utility of next-generation imaging in prostate cancer, highlighting the use of PSMA PET in this patient population.

Dr Koo on Treating Various Stages of Prostate Cancer

Philip J. Koo, MD, division chief, Diagnostic Imaging, Northwest Region Oncology, physician executive, Banner MD Anderson Cancer Center, discusses the treatment of patients with prostate cancer throughout the different stages of their disease.

Recommendations for treating patients with prostate cancer align closely across various published guidelines, Koo begins. Before initiating definitive therapy, oncologists should consider employing prostate-specific membrane antigen (PSMA) PET scans, particularly in cases where there's a heightened suspicion of metastatic disease, he says. The focus of PSMA PET scans isn't primarily on identifying the primary disease but rather on detecting metastatic sites, particularly in patients with unfavorable intermediate-, high-, or very high-risk disease; biomarker indications of heightened metastatic risk; or elevated risk as indicated by nomograms, Koo elucidates. Utilizing PSMA PET can aid in treatment planning before proceeding with procedures such as prostatectomy or radiation therapy, he shares.

Transitioning to the biochemical recurrence (BCR) stage, there's a need for a more nuanced approach to using PSMA PET scans, Koo expands. Although the prostate cancer field initially used these scans aggressively in patients with BCR, now it's advisable to consider their use more thoughtfully, especially in cases where metastasis-directed therapy is being contemplated, he adds. The necessity for PSMA PET is clearer in such scenarios, whereas its utility in other contexts remains subject to debate, Koo notes.

Evidence from trials such as the phase 3 EMBARK trial (NCT02319837) indicate that patients with high-risk biochemical recurrences can benefit from systemic therapies such as enzalutamide (Xtandi) alone or in combination with androgen deprivation therapy (ADT), he continues. This raises questions regarding the timing as well as the appropriateness of PSMA PET scans in such cases, he adds. For patients who present with castration-resistant disease, PSMA PET scans play a pivotal role in identifying candidates for radioligand therapy, representing a significant advancement in treatment optimization for this population, Koo concludes.

Philip J. Koo, MD, discusses the treatment of patients with prostate cancer throughout the different stages of their disease.

Philip J. Koo, MD

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Dr Koo on Challenges With PSMA PET in Prostate Cancer

Dr Koo on Treating Various Stages of Prostate Cancer