PSMA PET/CT Imaging Guides Treatment Selection in Recurrent Prostate Cancer

A rising prostate-specific antigen (PSA) level may be the first sign of recurrence, while microscopic disease can remain too small to detect on imaging. These changes can make treatment decisions more complex. A new case report shows how a multidisciplinary team adapted imaging and treatment across three recurrences in one patient.

Researchers at UCLA Health followed a 76-year-old man for more than a decade after prostatectomy. His PSA became detectable about three years after surgery. A prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) scan identified cancer in the prostate bed and several lymph nodes. He entered the first of three investigator-initiated clinical trials and received stereotactic body radiation therapy (SBRT), a focused treatment directed at visible disease.

When cancer later appeared in lymph nodes farther up the abdomen, he enrolled in the SATURN trial. He received SBRT with six months of intensive hormone therapy. His PSA initially fell but rose again, and a subsequent PSMA scan showed two new cancerous lymph nodes and another recurrence in the prostate bed.

For the third recurrence, he entered the phase 2 LUNAR trial. Treatment consisted of two cycles of ¹⁷⁷Lu-PNT2002, a PSMA-targeted radioligand designed to deliver radiation to PSMA-positive cancer cells, followed by SBRT. His PSA eventually became undetectable. PSMA scans at 12 and 24 months showed no active disease, and his PSA remained undetectable 10.5 years after prostatectomy.

The case report was published in CA: A Cancer Journal for Clinicians in 2026. The patient’s care drew on urology, radiation oncology, medical oncology, nuclear medicine and advanced imaging. The researchers note that ongoing randomized trials are examining when to use hormone therapy, which patients benefit from radiation directed at metastases, and how to integrate PSMA-targeted radioligand therapy.

“This isn't a story about one treatment being the answer. It's about bringing together different areas of expertise and using the evidence available at each point in a patient's journey to make the best treatment decision we can. As the cancer changes, our approach has to change with it,” said Dr. Amar Kishan, professor and executive vice chair of radiation oncology at the David Geffen School of Medicine at UCLA.

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