Comparison of 18F-PSMA PET/CT and mpMRI in the diagnosis of pelvic lymph node metastasis of prostate cancer / 中华泌尿外科杂志

ABSTRACT

Objective:To compare the diagnostic efficacy of 18F-prostate specific membrane antigen (PSMA)-1007 PET/CT and mpMRI in the diagnosis of pelvic lymph node metastasis of prostate cancer (PCa). Methods:The clinical data of 30 patients who underwent 18F-PSMA-1007 PET/CT and mpMRI examinations in Sichuan Cancer Hospital from November 2018 to April 2021 were analyzed. The average age was (68.4±6.4) years old. The preoperative total PSA was 45.70(16.07, 100.00)ng/ml. Among 30 patients, 14 cases were found lymph node positive by PET/CT and 7 cases were found lymph node positive by mpMRI.Combined with the two preoperative imaging methods and the patient's PSA level, there was 1 patient in stage T 1, 20 patients in stage T 2, 6 patients in stage T 3, and 3 patients in stage T 4. Twenty-nine cases were classified as high risk group and one case was in moderate risk group.All 30 patients underwent laparoscopic radical prostatectomy and enlarged pelvic lymph node dissection (ePLND). According to the postoperative pathological results, the sensitivity, specificity, positive predictive value and negative predictive value of the two imaging techniques for the diagnosis of PCa pelvic lymph node metastasis were calculated, and the consistency of the two imaging techniques for the postoperative pathological results was observed by Kappa test. Results:All the 30 patients were confirmed to be PCa by postoperative pathology, among which 10 patients were positive for pelvic lymph node biopsy. The sensitivity, specificity, positive predictive value and negative predictive value of 18F-PSMA-1007 PET/CT for pelvic lymph node metastasis were 100.0% (10/10), 80.0% (16/20), 71.4%(10/14) and 100.0%(16/16) respectively, and Kappa value was 0.727. The sensitivity and specificity of mpMRI were 70.0% (7/10) and 100.0% (20/20), the positive and negative predictive values were 100.0% (7/7) and 87.0%(20/23)respectively, and the Kappa value was 0.757. The P values of sensitivity, specificity, positive predictive value and negative predictive value between the two imaging methods were 0.18, 0.07, 0.30, <0.01, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of 18F-PSMA-1007 PET/CT in diagnosing the number of pelvic lymph node metastasis were 100%(28/28), 98.2% (373/380), 80.0% (28/35) and 100.0%(373/373), respectively. The sensitivity, specificity, positive predictive value and negative predictive value of mpMRI in diagnosing the number of pelvic lymph node metastasis were 78.6% (22/28), 100.0% (380/380), 100.0% (22/22) and 98.4%(380/386), respectively. The P values of the sensitivity, specificity, positive predictive value and negative predictive value of lymph node detection by the two imaging methods were all <0.01, and the differences were statistically significant. Conclusions:The sensitivity and negative predictive value of 18F-PSMA-1007 PET/CT for the detection of positive lymph node were higher than mpMRI. The specificity and positive predictive value of mpMRI in detecting positive lymph node metastasis were higher than 18F-PSMA-1007 PET/CT examination.