[Clinical value of ¹⁸F-PSMA-1007 PET/CT combined with serum total prostate specific antigen in predicting International Society of Urological Pathology pathological grading of prostate cancer].

<b>Objective:</b> To discuss the correlation of International Society of Urological Pathology (ISUP) pathological grading with¹⁸F-prostate specific membrane antigen (PSMA)-1007 positron emission tomography-computed tomography (PET/CT) parameters and serum total prostate specific antigen (tPSA) in prostate cancer, and assess the clinical value of PET/CT combined with tPSA in predicting the ISUP pathological grade of prostate cancer. <b>Methods:</b> The correlation of ISUP pathological grade with primary parameters of PET/CT images and serum tPSA of 117 patients diagnosed with prostate cancer at Shanxi Cancer Hospital from August 2018 to February 2023 and taken ¹⁸F-PSMA-1007 PET/CT imaging were retrospectively analyzed. Univariate and multivariate logistic regressions were used to identify the independent influencing factors for ISUP pathological grading of prostate cancer. The receiver operating characteristic (ROC) curves were used to predict the efficacy between the high and low ISUP grades for prostate cancer. <b>Results:</b> Of the 117 patients, 20 were in ISUP Group 1, 25 in Group 2, 18 in Group 3, 32 in Group 4, and 22 in Group 5. Of these, 63 were in the low-grade group (Groups 1-3) and 54 were in the high-grade group (Groups 4-5). The tumor long diameter was 3.10 (2.05, 4.25) cm, the prostate volume was 40.11 (33.13, 51.85) cm³, the serum tPSA was 19.71 (12.25, 42.83) ng/ml, the prostate specific antigen density (PSAD) was 0.51 (0.31, 1.01) ng·ml^-1·cm^-3, the maximum standard uptake value of the lesion (SUVmax) was 15.24 (10.87, 22.03), and the tumor/spleen uptake ratio (TSR) was 1.61 (1.08, 2.15) in the 117 patients. The correlation analysis displayed that the SUVmax, TSR, and tPSA were positively correlated with ISUP groups (<i>r</i>=0.640, 0.619, and 0.500, <i>P</i>＜0.01). The differences among SUVmax, TSR, long diameter, tPSA, and PSAD were statistically significant when compared among the five ISUP groups (<i>H=</i>48.98, 45.63, 26.82, 33.95, and 23.81, <i>P</i>＜0.001). The differencesin serum tPSA (<i>z</i>=5.19), PSAD (<i>z</i>=4.64), long diameter (<i>z</i>=3.19), SUVmax (<i>z</i>=5.57), and TSR (<i>z</i>=5.53) of the patients between the low-grade group and the high-grade group were statistically significant (<i>P</i>＜0.01). In multivariate analysis, TSR (<i>OR</i>=4.172, 95% <i>CI</i>: 2.095-8.308, <i>P</i>＜0.001) and the serum tPSA (<i>OR</i>=1.042, 95% <i>CI</i>: 1.014-1.070, <i>P</i>＜0.01) were independent influencing factors for ISUP grades. ROC analysis revealed that the area under the curve for the ¹⁸F-PSMA-1007 PET/CT parameters SUVmax and TSR to predict low- or high-grade ISUP for prostate cancer was 0.800 (95% <i>CI</i>: 0.717-0.883) and 0.797 (95% <i>CI</i>: 0.713-0.881), respectively. Among the 70 patients who underwent radical prostatectomy, the postoperative recurrence rate of high-grade ISUP patients was higher than that of low-grade patients (54.8% and 25.6%, <i>χ²</i>=6.21, <i>P</i>＜0.05). <b>Conclusions:</b> ¹⁸F-PSMA-1007 PET/CT has good application in predicting ISUP grading of prostate cancer. TSR and the serum tPSA are independent predictors for the pathological grade.