When PSA Rises but Bone Scan Is Negative: The Critical Role of 18F-FDHT PET/CT in Re-staging Advanced Prostate Cancer
Clinical Hook An 86-year-old man had already endured years of treatment for advanced prostate cancer. His prostate-specific antigen (PSA) level began to rise again despite ongoing luteinizing hormone-releasing hormone (LHRH) agonist therapy. Surprisingly, the bone scan showed no evidence of metastatic disease. For many clinicians, a normal bone scan might appear reassuring. Yet the patient's biochemical profile suggested otherwise. Was this simply biochemical recurrence, or was metastatic disease hiding beyond the limits of conventional imaging? A subsequent 18F-FDHT PET/CT answered that question decisively. The examination revealed extensive lymph node metastases above and below the diaphragm, multiple skeletal metastases, and high androgen receptor (AR) expression throughout the metastatic lesions. Based on these findings, the patient's treatment strategy changed from continued hormonal suppression alone to consideration of androgen receptor antagonist therapy. This case ...