Correlation of PSA blood levels with standard uptake value maximum (SUVmax) and total metabolic tumor volume (TMTV) in 18F-PSMA-1007 and 18F-choline PET/CT in patients with biochemically recurrent prostate cancer.

Abstract

Objectives: In this prospective study, we investigated the correlation between prostate-specific antigen (PSA) levels in the blood of patients with prostate cancer in biochemical recurrence after radical treatment with the semiquantitative parameters standard uptake value maximum (SUVmax) and the total metabolic tumor volume (TMTV) in the metastatic foci depicted in 18F-prostate-specific membrane antigen (PSMA)-1007 and 18F-choline PET/computed tomography (CT) imaging.

Methods: We prospectively examined 104 patients with biochemical relapse of prostate cancer after primary definitive treatment. All patients underwent one 18F-PSMA-1007 and one 18F-choline PET/CT examination in randomized order within a time frame of 10 days and were followed for at least 6 months (182 ± 10 days). The semiquantitative parameters of SUVmax and metabolic tumor volume (MTV) of each neoplastic lesion in PET/CT imaging were calculated, and further summation of each MTV value was done to calculate the TMTV.

Results: According to the Spearman correlation analysis, a positive correlation was found between PSA levels and SUVmax and TMTV scores in the metastatic foci of 18F-PSMA-1007 PET/CT (r = 0.24 and 0.35, respectively; P < 0.05) and SUVmax in the lesions of 18F-choline PET/CT (r = 0.28; P < 0.0239). However, a positive but NS correlation was demonstrated between values of PSA and TMTV for each lesion in the 18F-choline PET/CT study (r = 0.22; P = 0.0795). The detection rate of the different PSA levels with a cutoff of 1 ng/ml was higher for 18F-PSMA-1007 than 18F-choline.

Conclusion: In biochemical relapse patients there is a positive correlation between PSA levels in the blood and the semiquantitative parameters SUVmax and TMTV of the metastatic foci in the 18F-PSMA-1007 and 18F-Choline PET/CT imaging.