Spectrum of metastatic and nonmetastatic skeletal findings with dual-phase 18F-FECH PET/CT in patients with biochemical relapse of prostate cancer

Abstract

The aim of this study was to evaluate the spectrum of skeletal findings on dual-phase 18 Ffluoroethylcholine (FECH) PET/CT performed during the work-up of patients referred for suspected prostate cancer relapse. Tc-MDP planar bone scans and serum PSA. SUVmax for all except one benign lesion ranged from 0.49 to 2.15. In 51 lesions (71%) due to metastatic disease, SUVmax was 0.6-11.6 for those classified as sclerotic on lowdose CT, 0.7-8.58 for lytic lesions, 1.1-7.65 for isodense lesions, and 1.27-3.53 for mixed lytic/sclerotic lesions. Of the 56 18 F-FECH avid lesions, 21 lesions showed avidity on bone scan {3 (23%) of the 13 isodense lesions, 14 (40%) of the 35 3 sclerotic lesions, 2 (50%) of the lytic lesions, and 2 (50%) of the mixed sclerotic/lytic lesions}. . Methods Conclusion:18 F-FECH PET/CT identified bone lesions in 15% of patients with suspected prostate cancer relapse. SUVmax in isolation cannot be used to characterize these lesions as benign or malignant. Minimal overlap of benign and malignant lesions was seen above SUVmax of 2.5. Low-dose CT of PET/CT is a useful tool to assist characterization.