SNMMI: Over 80 Percent of Patients with Osseous Oligometastatic PCa are Upstaged with PSMA PET/CT

Emerging research demonstrates that a significant percentage of oligometastatic osseous prostate cancer (PCa) lesions detected with PSMA PET are missed on conventional imaging, resulting in significantly higher mortality risks.

In a retrospective analysis, presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) conference, researchers reviewed PSMA PET data from 1,020 patients. Initial baseline PSMA PET scans revealed oligometastatic osseous lesions in 36 patients, 28 of whom had negative findings on conventional imaging such as MRI, CT or bone scan, according to the study.

For patients with one osseous lesion, 80.8 percent were upstaged from M0 to M1 staging with PSMA PET. The researchers found that PSMA PET led to upstaging for 87.5 percent of those with two to five osseous lesions.

In comparison to patients with M0 staging on initial PSMA PET imaging, the study authors found that those with one to five osseous lesions had over a fivefold higher risk of progressing to castration-resistant prostate cancer (CRPC) and over a 3.8-fold higher mortality risk.

“PSMA PET/CT upstages over 80% of patients with osseous oligometastatic prostate cancer from clinical M0 to M1. These patients harbor aggressive histology and demonstrate significantly elevated risk of CRPC and death despite therapeutic intensification,” noted lead study author Surekha Yadav, MBBS, MD, who is a nuclear medicine resident at the University of California-San Francisco (UCSF), and colleagues.

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The study authors noted that all patients with oligometastatic disease were treated with systemic therapy. While metastasis-directed therapy (MDT) was utilized in 48 percent of patients with one osseous lesion and 22.2 percent of those with two to five lesions, a subgroup analysis showed that patients with one osseous lesion had a faster progression to CRPC.

“(This) suggests a therapeutic gap wherein limited visible disease may prompt less durable systemic regimens compared to higher-burden oligometastatic disease,” posited Yadav and colleagues.

Reference

1. Yadav S, Hong CM, Nwihim SO, et al. Longitudinal outcomes of PSMA PET/CT-detected oligometastases: a two-center study. Presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) conference, May 30-June 2, 2026, Los Angeles. Available at: https://jnm.snmjournals.org/content/67/supplement_1/262291 .