Imaging Discordance Between [⁶⁸Ga]-PSMA PET and [¹⁷⁷Lu]-PSMA SPECT in mCRPC

KÜÇÜKER C., Kaya G., ERGÜN E., UĞUR Ö., TUNCEL M.

Clinical Nuclear Medicine, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2026
  • Doi Number: 10.1097/rlu.0000000000006293
  • Journal Name: Clinical Nuclear Medicine
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE
  • Keywords: post-therapy SPECT/CT, prostate cancer, PSMA PET/CT, radioligand therapy, [177Lu]-PSMA-617, [68Ga]-PSMA-11
  • Hacettepe University Affiliated: Yes

Abstract

PSMA PET/CT is commonly used for selecting candidates for [¹⁷⁷Lu]-PSMA radioligand therapy (LuPSMA RLT). However, discrepancies may occur due to pharmacokinetic and biodistribution differences between [⁶⁸Ga]-PSMA-11 and [¹⁷⁷Lu]-PSMA-617 ligands. Such discordance risks underestimating disease burden and excluding eligible patients. We present a case of metastatic castration-resistant prostate cancer (mCRPC) in whom a PSMA-negative adrenal lesion on PET exhibited significant LuPSMA uptake post-therapy and was subsequently confirmed as FDG-avid. Complementary stereotactic body radiotherapy (SBRT) achieved metabolic remission. This case highlights the clinical significance of integrating post-therapy LuPSMA imaging and FDG PET/CT with systemic treatment to ensure accurate disease characterization and personalized management of PSMA−/FDG+ lesions in advanced prostate cancer.