68 Ga-PSMA PET/CT Identifies "Pseudo-progression" of Bone Lesions in Prostate Cancer Observed on 68 Ga-DOTA-IBA PET/CT.

We report a case where 68 Ga-PSMA PET/CT distinguished "pseudo-progression" from progression observed on 68 Ga-DOTA-IBA PET/CT. In a 75-year-old man with metastatic castration-resistant prostate cancer (mCRPC), 68 Ga-DOTA-IBA PET/CT revealed markedly increased tracer uptake in bone metastases compared with pretreatment imaging, suggesting radiologic progression. However, 68 Ga-PSMA-11 PET/CT images demonstrated the complete metabolic response (PERCIST 1.0), revealing "pseudo-progression" of bone lesions in 68 Ga-DOTA-IBA, especially when combined with clinical symptoms, PSA, and ALP levels.