Objective:To explore the effect of the labeled positron emission tomography/computed tomography(PET/CT)scan with Al18F-PSMA-BCH(Beijing Cancer Hospital)on early diagnosis and treatment decision of prostate cancer of biochemical recurrence.Methods:A total of 80 patients who underwent radical prostatectomy(RP)for prostate cancer(PCa)in the Kashgar First People's Hospital from August 2021 to June 2022 were retrospectively analyzed.According to the presence of biochemical recurrence(BCR),they were divided into biochemical recurrence group(n=29)and non-biochemical recurrence group(n=51).All patients were scanned with Al18F-PSMA-BCH PET/CT markers.The detection situations of the labeled scan with Al18F-PSMA-BCH on clinically local recurrence or metastasis of patients with BCR were analyzed.The correlations between the maximum standardized uptake value(SUVmax)of recurrence and metastasis,the serum prostate specific antigen(PSA)and Gleason scores were compared.The detection efficiency of SUVmax on BCR patients with different risk levels under labeled scan with Al18F-PSMA-BCH was analyzed.According to the preoperative PSA,Gleason score of obtaining from postoperative pathological results and clinical stage,80 patients were divided into low-risk grade,medium risk grade and high risk grade.Results:Under the labeled scan with Al18F-PSMA-BCH PET/CT,23 patients in biochemical recurrence group occurred clinical recurrence and metastasis(79.31%),of which 14 cases existed various degrees of lymph node metastasis(60.87%),including simple pelvic lymph node metastasis in 8 cases(34.78%),simple retroperitoneal lymph node metastasis in 2 cases(8.70%),pelvic with retroperitoneal lymph node metastasis in 3 cases(13.04%)and 1 case of supraseptal lymph node metastasis(4.35%).There were 4 cases of recurrence in prostatectomy area(17.39%),1 case of visceral metastasis(4.35%)(brain),and 15 cases with various degrees of bone metastasis(65.22%).For PCa patients with BCR after RP,the area under curve(AUC)of the receiver operating characteristic(ROC)curve of the labeled scan with Al18F-PSMA-BCH PET/CT was 0.897(95% CI:0.808-0.953,P<0.001)in detecting patients with clinical local recurrence or metastasis,and the sensitivity and specificity of that were respectively 79.3% and 100.00%.The SUVmax of patients with bone metastasis was(14.82±24.32),which was positively correlated with PSA level and Gleason score(r=0.442,0.372,P<0.001),respectively.The SUVmax of patients with recurrence in operation area was(24.38±26.54),which was positively correlated with PSA level and Gleason score(r=0.423,0.338,P<0.05),respectively.The SUVmax of patients with pelvic lymph node metastasis was(45.34±47.04),which was positively correlated with PSA level and Gleason score(r=0.423,0.316,P<0.05),respectively.At the same time,in these patients with BCR,the detection rate(100%)of recurrence or metastasis in patients with Gleason score≥8 was significantly higher than that in patients with Gleason score≤7(11/17,64.71%),and the difference was statistically significant(x2=6.502,P<0.05).There were significant differences in the detection rates among patients with 0.2 ng/ml≤PSA<0.5 ng/ml(6/10),patients with 0.5 ng/ml≤PSA<1 ng/ml(6/8),patients with 1 ng/ml≤PSA<2 ng/ml(12/12)and patients with PSA≥2 ng/ml(9/9)(x2=9.041,P<0.05).The AUC values of SUVmax for recurrence or metastasis in patients with low,medium and high-risk BCR were 0.708(95% CI:0.543-0.840,P＞0.05),0.780(95% CI:0.621-0.895,P<0.05)and 0.914(95% CI:0.781-0.979,P<0.001),respectively.The diagnostic efficiency of Al18F-PSMA-BCH on local recurrence and metastasis of patients with high-risk BCR was significantly better than that of patients with low-risk BCR(x2=8.986,P<0.05).In the 23 patients who underwent labeled scan with Al18F-PSMA-BCH,15 patients(65.22%)received the added treatment of local radiotherapy,systemic chemotherapy,endocrine therapy or pelvic lymph node dissection on the basis of the original treatment plan,which changed the treatment strategies.Conclusion:The labeled scan with Al18F-PSMA-BCH has higher early diagnostic value for BCR of patients with PCa,which will have a certain influence on the treatment strategy of patients.