Preliminary clinical study of99mTc-labelled small molecules against PSMA for prostate cancer imaging / 中国癌症杂志

ABSTRACT

Background and purpose:Prostate-speciifc membrane antigen (PSMA), a cell surface protein with high expression in prostate carcinoma (PC) cells, is an attractive target for PC imaging and therapy. Small-molecule radiopharmaceuticals targeting PSMA can detect the location and extent of disease with high sensitivity and speciifcity. The aim of this study was to evaluate the value of technetium-99m-labelled small molecule against PSMA (HYNIC-Glu-Urea-A,99mTc-PSMA) for the detection of primary and metastatic prostate cancers.Methods:Twenty-four prostate cancer patients and 1 patient with benign prostate hyperplasia received whole-body scan followed by abdominopelvic SPECT/CT 2 h after intravenous injection of99mTc-PSMA. Tumor to muscle uptake ratio of99mTc-PSMA was calcu-lated using region of interest (ROI) technology. The sensitivity and specificity of99mTc-PSMA were evaluated. The relationships between positive99mTc-PSMA and prostate speciifc antigen (PSA) level and Gleason Score were analyzed. Results:Based on per patient, the sensitivity and speciifcity of99mTc-PSMA were 72.7% (16/22) and 100% (3/3), re-spectively. The level of PSA in patients with positive99mTc-PSMA imaging was signiifcantly higher than that in patients with negative99mTc-PSMA imaging [(PSA median 17.31 ng/mL, range 2.26-3 239.0 ng/mL)vs(PSA median 0.49 ng/mL, range 0.07-9.28 ng/mL)] (Z=-3.51,P<0.001). Among newly diagnosed patients and recurrent patients with PSA more than 2.0 nm/mL, it was apparent that99mTc-PSMA imaging was able to detect lesions with improved sensitivity of 94.1% (16/17). Gleason Scores between positive99mTc-PSMA patients and negative99mTc-PSMA patients were not significantly different (Z=-0.69,P=0.52).Conclusion:With the combination of whole-body scan and tomography, 99mTc-PSMA SPECT/CT can be an excellent and speciifc molecular imaging strategy to detect prostate cancer and its metastases.