Résumé
Objective:To explore the feasibility of radical prostatectomy without biopsy for patients with highly suspected localized prostate cancer diagnosed by multiparametric magnetic resonance imaging (mpMRI) and 68Ga-PSMA PET/CT. Methods:Patients were enrolled in this single-arm prospective study from March 2019 to January 2022 in the Second Hospital of Tianjin Medical University. Eligible patients were aged ≤80 years with an Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1. Based on mpMRI and 68Ga-PSMA PET/CT, patients were diagnosed with highly suspected localized prostate cancer with no evidence of distant lymphatic, bone or visceral metastases. Patients were excluded if they had obvious important organs dysfunction, suspected metastatic lesions or history of other malignant tumor. After fully informed of the surgical risks and possibilities of final pathology, patients received laparoscopic or robot-assisted laparoscopic radical prostatectomy. According to final pathological results, the diagnostic accuracy of mpMRI and 68Ga-PSMA PET/CT was evaluated. Pathological features were compared between low 68Ga-PSMA PET/CT maximum standardized uptake value (SUV max) group (SUV max<10) and high SUV max group (SUV max≥10). Baseline characteristics were compared between clinically significant prostate cancer (CsPCa) and clinically insignificant prostate cancer (cisPCa) + high grade prostatic intraepithelial neoplasia (HGPIN) patients. Additional analysis of the correlation between baseline parameters and different subgroups including pathological stage, ISUP grades and risk groups were performed in CsPCa patients. Results:31 patients were enrolled. Median age was 68 (ranging 48-79)years old. Median BMI was 25.6(ranging 21.9-31.4)kg/m 2. Median prostate specific antigen (PSA) was 23.5 (ranging 5.6-94.7)ng/ml. Median prostate volume was 37.6(ranging 16.2-127.9)ml. Median PSA density (PSAD) was 0.56(ranging 0.11-2.86)ng/ml 2. Fifteen cases were scored prostate imaging reporting and data system (PI-RADS) 4 and 16 cases were scored PI-RADS 5. Median 68Ga-PSMA PET/CT SUV max was 13.3 (ranging 4.6-36.7). All surgeries were successfully accomplished without open conversion. Median postoperative hospitalization time was 5 (ranging 4-7)d. No major complication occurred perioperatively. Recovery of urinary continence was within 6 months in all patients. According to the final pathological results, 1(3.2%) patient was confirmed with HGPIN. 30 (96.8%) patients were confirmed with adenocarcinoma, including 26 (86.7%) patients with CsPCa and 4(13.3%) patients with cisPCa. Among prostate cancer cases, the pathological stage of 11(36.7%) was T 2 and 19(63.3%) was T 3. Four(13.3%) cases were with ISUP grade 1, 7(23.3%) cases were with ISUP grade 2, 7(23.3%) cases were with ISUP grade 3 and 12 (40.0%) cases were with ISUP grade≥4.Two(6.7%) cases were in low risk group, 3(10.0%) cases were in intermediate risk group and 25 (83.3%) cases were in high risk group. Twelve(40.0%) patients had positive surgical margins. Standard pelvic lymph node dissection was carried out in 18 (17 prostate cancer and 1 HGPIN) cases. Sixty-two lymph nodes were dissected and none of them was positive. The diagnostic accuracy of mpMRI and 68Ga-PSMA PET/CT was 96.8%(30/31) in prostate cancer. Compared to low SUV max group, patients in high SUV max group had higher ISUP grade ( P=0.003) but there was no significant difference in positive surgical margin, seminal vesical invasion or pathological stage ( P>0.05). Among CsPCa patients, 10 (38.5%) cases were scored PI-RADS 4 and 16(61.5%) cases were scored PI-RADS 5. Median 68Ga-PSMA PET/CT SUV max was 14.3 (range 6.1-36.7). Compared to cisPCa and HGPIN patients, a smaller median prostate volume (34.3 vs. 73.0 ml, P=0.006), higher median PSAD (0.70 vs. 0.13 ng/ml 2, P=0.001), higher rates of PI-RADS 5 patients (61.5% vs. 0, P=0.018) and higher 68Ga-PSMA PET/CT SUV max (14.3 vs. 6.1, P=0.001) were found in CsPCa patients. Subgroup analysis showed no significant difference between SUV max and pathological stage (25.5 vs. 13.9), ISUP grades (15.4 vs. 14.4 vs. 14.0) and risk groups (9.7 vs. 14.9) in CsPCa patients ( P>0.05). Conclusions:The diagnostic accuracy of mpMRI and 68Ga-PSMA PET/CT is high in prostate cancer. With efficient communication, radical prostatectomy without biopsy for patients with highly suspected localized prostate cancer diagnosed by mpMRI and 68Ga-PSMA PET/CT is safe.