68Ga-PSMA PET/CT-targeted biopsy for the diagnosis of clinically significant prostate cancer in patients with serum PSA levels <20.0 ng/ml / 中华泌尿外科杂志

ABSTRACT

Objective:To evaluate the feasibility and efficacy of 68Ga-PSMA PET/CT-guided targeted prostate biopsy for the diagnosis of clinically significant prostate cancer(csPCa). Methods:This retrospective analysis allocated 89 patients with elevated PSA levels between 4.0-20.0 ng/ml to PET group(n=48) or TRUS group(n=41) between September 2017 and June 2019. Patients with PSMA-avid lesions (SUV max≥8.0) underwent PET-TB via a single-puncture percutaneous transgluteal approach (n=19), while patients with negative PSMA-PET underwent systematic TRUS-GB (n=29). Patients in the TRUS group who did not get 68Ga-PSMA PET/CT examination underwent TRUS-GB directly (n=41). The mean age, prostate volume, PSA value of PET group and TURS group were (71.2±9.1) years vs. (68.0±12.0) years, (62.9±29.1)ml vs. (65.4±38.9)ml , 8.8(6.6, 13.6) ng/ml vs. 9.8(7.1, 13.1)ng/ml, respectively (all P>0.05). The diagnostic efficacy and difference of PCa and csPCa between the two groups were compared. PET-TB adopts a new mode of percutaneous gluteus approach and carries out precise image fusion of PSMA-PET/CT and pelvic CT in the same machine and in the same position (prone position). Under the direct guidance of CT, the biopsy is performed with only one precise puncture. Results:PCa and csPCa were detected in 27/89(30.3%)and 20/89(22.5%)in all patients. PET group detected significantly more cases of PCa and csPCa than those of TRUS group [PCa 41.7%(20/48) vs. 17.1%(7/41), χ2=6.328; csPCa 33.3%(16/48) vs. 9.8%(4/41), χ2=7.055, P<0.01]. Of 19 patients with PSMA-PET positive, PET-TB detected 16 cases of PCa(84.2%) by a single needle puncture, and the proportions of cancer tissues were ≥80% in 2, 50%-79% in 8, and <50% in 6 cases. Among these, Gleason score was underestimated by biopsy histopathology in 2 patients. Of 3 patients with PET-TB negative, 1 case of low-risk PCa(Gleason 3+ 3) was detected by complementary TRUS-GB. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of 68Ga-PSMA PET/CT(SUV max≥8.0) for the diagnosis of csPCa were 73.9%(14/19), 93.1%(27/29), 87.5%(14/16), 81.3%(26/32)and 85.4%(41/48), respectively. For PET-TB, only one patient had slight symptoms of haematuria after the puncture, no cases of hematochezia, hemospermia, urinary retention or pelvic infection were observed. Conclusions:68Ga-PSMA PET/CT is a feasible novel puncture technique that may serve as a triage tool for prostate biopsy, and PET-TB may improve the detection rate of csPCa compared with TURS-GB, especially in patients with serum PSA 4.0-20.0 ng/ml.