Predictive value of ¹⁸F-PSMA-1007 PET/MR-derived parameters for risk stratification and metastatic status in newly diagnosed prostate cancer

Objective  This study aimed to explore the predictive value of ¹⁸F-prostate specific membrane antigen (PSMA)-1007 PET/MR-derived parameters for risk stratification and metastatic status in newly diagnosed prostate cancer (PCa).

Methods  A retrospective analysis was conducted on the images and clinical data of 46 patients with newly diagnosed PCa (aged 49-86(69.9±9.7) years) who underwent ¹⁸F-PSMA-1007 PET/MR examination in the First Affiliated Hospital of Naval Medical University from April 2023 to January 2024. In accordance with the risk stratification recommended by the guidelines of National Comprehensive Cancer Network and the occurrence of tumor metastasis, patients were divided into binary groups: high-risk and intermediate-low-risk groups as well as metastasis and non-metastasis groups. The Mann-Whitney U test was used to compare intergroup differences in maximum standardized uptake value (SUV_max), minimum apparent diffusion coefficient (ADC_min), tumor volume of PSMA (PSMA-TV), and total lesion of PSMA (TL-PSMA) of primary lesions. The receiver operating characteristic (ROC) curve was used to evaluate the predictive efficacy of various parameters for high-risk PCa and metastatic PCa.

Results  Among the 46 PCa patients, including 36 cases in the high-risk group and 10 cases in the intermediate-low-risk group as well as 15 cases in the metastasis group and 31 cases in the non-metastasis group. Comparing the group with high-risk and that with intermediate-low-risk, there were statistically significant differences (Z=−3.888 to 3.955, all P<0.05) in SUV_max (28.6(17.9, 44.0) vs. 14.7(9.7, 22.8)), ADC_min (0.733(0.647, 0.822)×10⁻³ mm²/s vs. 0.951(0.906, 1.009)×10⁻³ mm²/s), PSMA-TV (17.5(11.8, 46.0) cm³ vs. 5.5(2.6, 10.1) cm³), and TL-PSMA (155.0(78.2, 342.0) cm³ vs. 29.8(16.4, 45.4) cm³) . Comparing the group with metastasis and that with non-metastasis, there were statistically significant differences (Z=−3.234 to 2.542, all P<0.05) in SUV_max (42.4(20.0, 50.0) vs. 20.4(11.9, 33.8)), ADC_min (0.661(0.578, 0.743)×10⁻³ mm²/s vs. 0.808(0.727, 0.949)×10⁻³ mm²/s), PSMA-TV (34.1(12.6, 64.2) cm³ vs. 11.7(7.5, 18.6) cm³), and TL-PSMA (260.1(117.7, 495.0) cm³ vs. 78.1(33.3, 159.1) cm³). The results of the ROC curve analysis demonstrated that the AUCs for predicting high-risk PCa using SUV_max, ADC_min, PSMA-TV, and TL-PSMA were 0.783(95%CI: 0.637-0.891), 0.906(95%CI: 0.782-0.972), 0.913(95%CI: 0.791-0.976) and 0.908(95%CI: 0.786-0.973), respectively. The AUCs for predicting metastatic PCa using SUV_max, ADC_min, PSMA-TV, and TL-PSMA were 0.733(95%CI: 0.582~0.853), 0.797(95%CI: 0.652~0.901), 0.706(95%CI: 0.554~0.831), and 0.723(95%CI: 0.571~0.844), respectively.

Conclusions  The parameters derived from ¹⁸F-PSMA-1007 PET/MR can be used as noninvasive imaging biomarkers for preoperative prediction of risk stratification and metastatic status in newly diagnosed PCa.