Detection value of 18F-PSMA-1007 PET/CT in the recurrence of prostate cancer at low serum prostate specific antigen level / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the value of 18F-prostate specific membrane antigen (PSMA)-1007 PET/CT in the detection of prostate cancer recurrence at low serum prostate specific antigen (PSA) level. Methods:From July 2018 to June 2019, 45 patients (age 59-74 years) with suspected biochemical recurrence of prostate cancer with low PSA level (<2.0 μg/L) who underwent 18F-PSMA-1007 PET/CT examinations in Shanxi Tumor Hospital were retrospectively analyzed. Four patients with PSA<0.2 μg/L were not included in the statistical analysis due to the small sample. Among the remaining 41 patients with 0.2 μg/L≤PSA<2.0 μg/L, 10 were with 0.2 μg/L≤PSA<0.5 μg/L, 14 were with 0.5 μg/L≤PSA<1.0 μg/L, 17 were with 1.0 μg/L≤PSA<2.0 μg/L. PET/CT imaging were performed within 2 weeks after the examination of serum PSA. All patients were divided into low-moderate-risk group ( n=12) and high-risk group ( n=29) according to the National Comprehensive Cancer Network (NCCN) guidelines. χ2 test, Fisher′s exact test and Spearman rank correlation were used to analyze the data. Results:Patients were followed up for 7 (4-15) months, and all 45 patients were confirmed by pathology or follow-up. There were 31 patients with recurrence and 14 patients without recurrence. The sensitivity, specificity and accuracy were 100%(31/31), 13/14, 97.78%(44/45)respectively. One patient with PSA<0.2 μg/L presented retroperitoneal lymph node metastasis. Among 41 patients with 0.2 μg/L≤PSA<2.0 μg/L, 31(75.61%) were with at least one recurrent lesion by 18F-PSMA-1007 PET/CT. There were 20 cases of local recurrence, 13 cases of lymph node metastasis, 14 cases of bone metastasis. The detection efficacies of 18F-PSMA-1007 PET/CT were 5/10 for patients with 0.2 μg/L≤PSA<0.5 μg/L, 11/14 for those with 0.5 μg/L≤PSA<1.0 μg/L, and 15/17 for those with 1.0 μg/L≤PSA<2.0 μg/L ( χ2=4.641, P>0.05). The positive results of 18F-PSMA-1007 PET/CT were positively correlated with serum PSA value and risk group ( r values 0.394, 0.384, both P<0.05). Conclusion:18F-PSMA-1007 PET/CT is a valuable tool for detecting biochemical recurrence of prostate cancer with low PSA level.