Application of ⁹⁹Tc^m-PSMA137 SPECT/CT imaging in the diagnosis of prostate cancer

Objective To explore the application of ⁹⁹Tc^m-prostate specific membrane antigen (PSMA)137 SPECT/CT imaging in the diagnosis of prostate cancer.

Methods A retrospective cohort analysis was conducted on the clinical data, imaging data, and histopathological findings of 82 patients diagnosed with prostate cancer who underwent ⁹⁹Tc^m-PSMA137 SPECT/CT imaging and MRI at the First Affiliated Hospital of Xi'an Jiaotong University from September 2022 to April 2024. The patients had a median age of 69 years, and an age range of 52–84 years. The imaging results were analyzed quantitatively with the assistance of artificial intelligence, measured the maximum diameter of the lesion and the maximum standardized uptake value (SUV_max) of lesions was calculated. Gleason scoring was performed in accordance with the Consensus on specimen handling and pathological diagnosis of prostatic carcinoma (2021 version). Pearson correlation analysis was employed to evaluate the correlations of SUV_max with age, serum prostate-specific antigen (PSA) levels, and histopathological results. The Kruskal-Wallis test was applied to compare differences in SUV_max among patients with different Gleason scores, and the Dunn test was used for pairwise comparisons. The chi-square test was used to compare the detection rates of primary lesions among different imaging examination methods.

Results Among 82 prostate cancer patients, 80 (97.6%) had prostate adenocarcinoma and 2 (2.4%) had prostate cancer with ductal adenocarcinoma. ⁹⁹Tc^m-PSMA137 SPECT/CT imaging detected primary lesions in 76 patients (92.7%, 76/82), with abnormal uptake observed in bone tissue in 12 patients (14.6%, 12/82), lymph nodes in 2 patients (2.4%, 2/82), the adrenal gland in 1 patient (1.2%, 1/82), the seminal vesicle in 1 patient (1.2%, 1/82), and pelvic soft tissue in 1 patient (1.2%, 1/82). Lesion SUV_max showed a significant positive correlation with serum PSA level (r=0.727, P<0.001), but no significant correlations were observed with patient age or lesion maximum diameter (r=−0.122, 0.008; P=0.294, 0.950). The SUV_max for Gleason scores of 6 to 10 were 4.039±0.153, 4.435±0.275, 6.024±1.199, 14.401±2.011, and 6.690±2.550, respectively. A statistically significant difference in SUV_max was found among patients with different Gleason scores (H=10.140, P=0.038). Specifically, statistically significant differences in SUV_max were observed between patients with Gleason scores of 6 and 9, as well as between those with Gleason scores of 7 and 9 (Z=−2.881, −2.926; P=0.037, 0.035). The detection rate of primary lesions in prostate cancer using ⁹⁹Tc^m-PSMA137 SPECT/CT imaging was superior to that of MRI ((92.7%, 76/82) vs. (81.8%, 54/66)) (χ²=4.041, P=0.044).

Conclusion ⁹⁹Tc^m-PSMA137 SPECT/CT imaging has important application value in the diagnosis of prostate cancer.