Objective:To explore the preoperative 68Ga-PSMA PET/CT examination on the guidance of surgical strategies for high-risk prostate cancer patients and the influence of positive surgical margins after surgery. Methods:The clinical data of 118 patients with high-risk prostate cancer who underwent robot-assisted laparoscopic radical prostatectomy from June 2019 to December 2020 in Xijing Hospital of Air Force Military Medical University was retrospectively analyzed. 47 patients received 68Ga-PSMA PET/CT examination before surgery (study group), and 71 cases without 68Ga-PSMA PET/CT examination before operation ( control group). There was no statistically significant difference in the age [69 (63, 76) vs. 67 (64, 74) years], PSA [PSA≤20ng/ml: 9.91 (6.00, 13.67) vs. 11.64 (8.15, 15.44) ng/ ml, PSA> 20ng/ml: 66.53 (53.66, 195.30) vs. 63.18 (30.08, 148.05) ng/ml], preoperative clinical staging (T 2/≥T 3: 21/26 cases vs. 34/37 cases), and Gleason score [8 (7, 9) vs. 8 (7, 9) points] (all P>0.05) between study group and control group. Both groups underwent robot-assisted laparoscopic radical prostatectomy. The surgical plan was based on the PSMA PET/CT and MRI results in study group and control group respectively. First, ensure that all tumors are removed, and secondly, preserve the patient's urethral length as much as possible to ensure postoperative urinary control.If there is seminal vesicle invasion, expand the scope of resection as needed. If lymph node metastasis is shown, lymph node dissection is performed. For those with negative lymph nodes in imaging studies, if enlarged lymph nodes are found during the operation, lymph node dissection is also performed. After the operation, the perioperative results and surgical margins of the two groups were compared, and the correlation between the PSA value and the SUVmax value of prostate cancer tissue was analyzed. Results:The operations of the two groups were successfully completed, and there was no transfer to open surgery. The operation time of the study group was shorter than that of the control group [175 (155, 205) min vs. 205 (155, 235) min, P=0.003], and the positive rate of resection margin was significantly lower than that of the control group [23.40% (11/47) vs. 45.07%(32/71), P=0.017]. For patients with pathological stage ≥pT 3, the positive rate of surgical margins in the study group was significantly lower than that in the control group [30.77%(8/26) vs. 62.16%(23/37), P=0.014]. In the study group, 11 cases of PSMA-PET showed positive lymph nodes before operation, 10 cases were pathologically positive after operation (90.91%). PSMA-PET showed negative lymph nodes in 1 case, which was pathologically positive after operation. In the control group, 26 cases underwent lymph node dissection, and 16 cases (61.54%) were pathologically positive after operation. The preoperative PSA value of 47 cases in the study group was positively correlated with the SUVmax value of prostate cancer tissue ( r=0.579, P<0.01). Conclusions:Preoperative 68Ga-PSMA PET/CT for high-risk prostate cancer patients can guide the surgeon to optimize the surgical plan, reduce the positive rate of resection margins, and effectively remove the metastatic lymph nodes, which will benefit the patients.

Objective:To investigate the efficacy and safety of radium-223 in combination with new-generation hormonal agents in patients with bone metastases of prostate cancer.Methods:The clinical data of 17 patients (12 from the First Affiliated Hospital of Airforce Military Medical University and 5 from Xi'an International Medical Center Hospital) with metastatic castration-resistant prostate cancer(mCRPC) treated by radium-223 combined with new-generation hormonal agents from January 2021 to June 2022 were retrospectively analyzed. In all cases, the average age was (73.3±8.5) years old. Before treatment, the median prostate-specific antigen (PSA) was 15.7 (3.2, 36.5) ng/ml, the median alkaline phosphatase (ALP) was 131.5 (79.0, 430.7) U/L. All patients had ≥ 2 bone metastases but no visceral or lymph node metastases. The median number of bone scan lesions was 10(8, 15). Bone pain symptom was present in 16(94.1%) patients. There were 9 cases (52.9%) with Eastern Cooperative Oncology Group (ECOG) score of ≥2, 1 case (5.9%) with ECOG score of 1 and 6 cases (35.2%) with ECOG score of 0. All patients were treated with radium-223 (55 kBq/kg, injected every 4 weeks for a maximum of 6 cycles), of which 5 patients were combined with enzalutamide, 8 patients combined with apatamide and 4 patients combined with bicalutamide. PSA response (PSA decreased by ≥30% from baseline and maintained for at least 1 month), ALP response (ALP decreased by ≥30% from baseline and maintained for at least 1 month) and pain relief rates were analyzed. Imaging evaluation was performed before and after treatment to calculate the objective response rate of metastases. The incidence of treatment-related adverse effects and skeletal related event (SRE) were also recorded.Results:Eleven patients completed 6 courses, 3 patients completed 5 courses and 3 patients completed ≥4 courses. The median ALP after 1 month of last treatment was 83.2 (51.5, 126.5) U/L, which was significantly decreased than baseline. 12 patients (70.6%) showed an ALP response and the other 5 (29.4%) showed varying degrees of ALP elevation. PSA response was observed in 4 patients (23.5%), of which 2 (11.8%) had a continuous decrease and 2 (11.8%) had a late-stage increase in PSA. Pain relief was relieved in 15 cases (88.2%) during treatment, 1 case (5.9%) had worsening pain due to disease progression and 1 case (5.9%) had no change during treatment. The ECOG score decreased in 15 (88.2%) patients. The median number of bone metastases in patients decreased to 5 (4, 9). One patient (5.9%) had complete remission during treatment, 11 patients (64.7%) had a partial response, 4 patients (23.5%) were stable, and 1 (5.9%) showed imaging progression after 4 months of treatment. The overall objective remission response rate was 70.5% (12/17). Treatment-related hematologic adverse effects included anemia (1 case, 5.9%, grade 3), thrombocytopenia (1 case, 5.9%, grade 3) and leukopenia (1 case, 5.9%, grade 2). Non-hematologic adverse effects included fatigue (3 cases, 17.6%, 2 cases in grade 1, 1 case in grade 2), gastrointestinal bleeding (1 case, 5.9%, grade 3), diarrhea (1 case, 5.9%, grade 2) and fever (1 case, 5.9%, grade 1). Patients with grades 1 to 2 relieved with symptomatic management. Three cases (17.6%) were discontinued due to intolerance of grade 3 adverse reactions and 1 case (5.9%) terminated on its own. There was no SRE during treatment and follow-up.Conclusions:Radium-223 combined with New-generation hormonal agents has a high objective remission rate in patients with mCRPC, which could provide pain relief and improve quality of life. The incidence of adverse reactions was low and well tolerated.