Prostate Cancer Case Review: Selecting Radioligand Therapy Candidates

In "Prostate Cancer Case Review: Selecting Radioligand Therapy Candidates," the panel reviews a 69-year-old with metastatic castration-resistant prostate cancer being considered for lutetium-based radioligand therapy.

Dr. Mendel presents the third case: a 69-year-old man with metastatic castration-resistant prostate cancer previously treated with ADT, an androgen-receptor pathway inhibitor, and docetaxel, now with progressive urinary symptoms and pelvic pain. Conventional imaging showed pelvic and retroperitoneal nodal disease with multifocal bone metastases, and the patient is being evaluated for lutetium-177 PSMA radioligand therapy. Dr. Mendel explains that PSMA PET avidity across metastatic sites is essential before proceeding, since non-avid lesions, including any transformation toward neuroendocrine disease, will not respond to radioligand therapy and would instead need alternative systemic treatment. He notes that disease volume also matters, since a patient with a single avid lesion after prior therapy might do better with stereotactic radiation to preserve future treatment options.

Reviewing the scans, Dr. Ghesani highlights a rib lesion visible on gallium PSMA but absent on a fluorine scan performed three weeks earlier, noting that prostate cancer rarely progresses that quickly and crediting an alert technologist who confirmed no trauma history. Post-therapy imaging later confirmed and treated that same rib lesion. Dr. Yonover raises the theoretical concern that androgen deprivation and receptor pathway inhibitors can alter PSMA expression, meaning sequencing systemic therapy relative to radioligand therapy could meaningfully affect its efficacy. Dr. Mendel agrees this deserves prospective study and describes anecdotal reports of patients receiving many retreatment cycles over years as disease recurs and resolves. Both physicians discuss cost as a major barrier, noting radioligand therapy's expense relative to older chemotherapy, and Dr. Ghesani describes proactive strategies his practice uses to mitigate salivary gland and other toxicities, including hydration, frequent voiding, and sialogogues, particularly important since durable responses may allow patients to receive additional treatment cycles over time.

The panel closes by anticipating future dosimetry-guided dosing and combination alpha- and beta-emitting radioligand approaches. Thank you for watching this Urology Times Virtual Tumor Board series on advanced prostate cancer. Please subscribe to our eNewsletter for information on upcoming video series.