Nuclear Medicine

Negative PSMA PET May Permit Omission of Pelvic Lymph Node Dissection in Intermediate-Risk Prostate Cancer

This meta-analysis of 12 studies (1619 intermediate-risk patients) found pooled PSMA PET/CT sensitivity 49% and specificity 95% for nodal invasion. The pooled negative predictive value for lymph node invasion was 95%, suggesting many PSMA-negative patients may omit pelvic lymph node dissection. However, modest sensitivity indicates PSMA PET often misses micrometastatic nodal disease, so some positive nodes will be left behind. The authors recommend cautious, individualized omission of dissection, emphasizing shared decision-making and need for prospective outcome validation. 1

PSMA PET Detects Radiographic Progression in Prostate Cancer Despite Undetectable PSA Levels

In a registry of 2141 patients, 257 (12%) had radiographic disease progression on PSMA PET/CT despite undetectable PSA (PSA zero rDP). Patients spanned localized, de novo metastatic, and castration-resistant states, with bone metastases most common, followed by nodal, visceral, and local sites. Seventy-two percent developed castration-resistant disease, and visceral metastases were the only factor significantly associated with worse overall survival. These data support considering periodic advanced imaging in high-risk patients, even with undetectable PSA, to identify occult progression earlier. 2

Harmonized [68Ga]PentixaFor PET Criteria Improve Lateralization and Confidence in Primary Aldosteronism

Thirty-five primary aldosteronism patients underwent [68Ga]PentixaFor PET/CT, with three independent blinded reads to test harmonized interpretation criteria. Inter-reader agreement between local and external readers improved from 80% to 94% after applying harmonized criteria adapted from metomidate experience. Using harmonized criteria, 11 of 35 scans were classified as high and 10 as intermediate unilateral probability, refining surgical decision-making. Among 22 patients with AVS, combining AVS and PET increased high-confidence unilateral diagnoses to 55%, especially when AVS was partial. Twelve adrenalectomies showed high biochemical remission rates, particularly when PET informed lateralization, supporting PET as a noninvasive adjunct to AVS. 3

Occupational Doses During TARE Are Low but Highest for Interventional Radiologists and 90Y-Resin Handling

This prospective single-center study monitored 53 staff during 60 TARE procedures using 90Y-resin, 90Y-glass, and 166Ho-PLLA microspheres. Per procedure, body doses were generally under 5 µSv and hand doses under 350 µSv, indicating low occupational exposure overall. 166Ho-PLLA caused the highest body doses due to gamma emissions and higher administered activity, while 90Y-resin produced the highest hand doses from handling. Interventional radiologists received the highest mean body and hand doses because of angiography and close proximity during delivery. The authors advise efficient 90Y-resin portioning and administration using long tweezers and trained staff to minimize extremity exposure. 4