⁶⁸Ga-PSMA PET/CT Promising for Lymph Node Staging in Prostate Cancer

By HealthDay News - Last Updated: February 23, 2022

WEDNESDAY, Feb. 23, 2022 (HealthDay News) — For patients with intermediate- and high-risk prostate cancer (PCa), 68Ga-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has promising diagnostic accuracy for lymph node (LN) staging before radical prostatectomy, according to a study published in the January issue of Urologic Oncology: Seminars and Original Investigations.

Selcuk Erdem, MD, from Istanbul University in Turkey, and colleagues examined the diagnostic accuracy of 68Ga-PSMA PET/CT on primary LN staging in 49 patients with intermediate- and high-risk nonmetastatic PCa (22 and 27 patients, respectively) before radical prostatectomy. The histopathology of dissected LNs was used as a reference standard to assess the accuracy of 68Ga-PSMA PET/CT in analyses conducted per patient and per node (49 patients, and 454 nodes).

The researchers found that five patients (10.2%) had histopathologically proven LN metastasis; three (60%) were detected with 68Ga-PSMA PET/CT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for 68Ga-PSMA PET/CT on primary LN staging were 0.60, 0.96, 0.60, and 0.96, respectively, in a per-patient analysis. Overall, 16 LNs (3.5%) were reported as metastatic in histopathology; 13 (2.9%) were detected using 68Ga-PSMA PET/CT. The sensitivity, specificity, PPV, and NPV of 68Ga-PSMA PET/CT on primary LN staging were 0.82, 0.99, 0.87, and 0.99, respectively, in a per-node analysis. For primary LN staging, the receiver operating characteristic analyses revealed areas under the curve of 0.777 and 0.904 in per-patient and per-node analyses, respectively.

“Extended pelvic lymph node dissection remains standard of staging for now, and the efforts should be taken to increase sensitivity of 68Ga-PSMA PET/CT in [the] individualized treatment era,” the authors write.

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