Awareness of the high rate of false positive [ 68 Ga]Ga-prostate specific membrane antigen-11 uptake in the prostate gland: can PET/MRI solve this problem?


Uslu-Beşli L., BAKIR B., Urganci N., GÜRSES İ., KARAYEL E., PEHLİVANOĞLU H., ...Daha Fazla

Nuclear medicine communications, cilt.47, sa.1, ss.88-98, 2026 (SCI-Expanded, Scopus) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 47 Sayı: 1
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1097/mnm.0000000000002071
  • Dergi Adı: Nuclear medicine communications
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE
  • Sayfa Sayıları: ss.88-98
  • Anahtar Kelimeler: false positive PSMA uptake, multiparametric prostate imaging, PET, PET/MRI, PIRADS, PRIMARY score, prostate cancer, prostate-specific membrane antigen
  • İstanbul Üniversitesi Adresli: Evet

Özet

OBJECTIVE: To assess the false positive gallium-68-labeled urea-based prostate-specific membrane antigen ( 68 Ga-PSMA) uptake rate in the prostate gland in patients with primary prostate cancer (PCa), and determine whether multiparametric prostate MRI (mpMRI) within hybrid PET/MRI can reduce false positives. METHODS: Fifty-one treatment-naive patients with PCa undergoing radical prostatectomy were prospectively recruited. All underwent 68 Ga-PSMA-11 PET/MRI with mpMRI. Images were assessed independently by the nuclear medicine physicians and radiologist using PRIMARY score and PIRADS v2.1, then jointly as fused PET/MRI. Radical prostatectomy followed imaging after a mean interval of 46 ± 32 days. Imaging findings were compared with postoperative histological mapping. Prostate was divided into sextants for lesion localization, and false positive uptake was recorded. Diagnostic performance metrics were calculated. RESULTS: Seven of 51 patients (13.7%) exhibited false positive PSMA uptake because of benign findings - asymmetrical central zone thickening, benign prostatic hyperplasia, or prostatitis. mpMRI was true negative in all. PET/MRI showed higher sensitivity and accuracy (74.9 and 83.0%) than PET (65.0 and 74.5%) and mpMRI (66.5 and 77.5%). For index lesion detection, PET/MRI had 92.2% sensitivity, outperforming PET (80.4%) and mpMRI (86.3%). PET/MRI was significantly more accurate than mpMRI ( P < 0.001) and PET ( P = 0.014), while PET and mpMRI were similar ( P = 0.770). CONCLUSION: False positive 68 Ga-PSMA uptake is common and can affect clinical decisions, including focal therapy or recurrence assessment after radiotherapy. mpMRI helps clarify benign mimics, improving diagnostic accuracy. PET/MRI may offer more reliable assessment of PCa, potentially aiding focal therapy planning and posttreatment evaluation.