Search

Background and purpose: Androgen deprivation therapy (ADT) is a key primary treatment for prostate cancer. However, there is still a lack of direct and accurate assessment method for the changes in the lesions after ADT treatment. The aim of this study was to explore the value of multiparametric magnetic resonance imaging (mpMRI) combined with technetium-99m labelled small molecule against prostate specific membrane antigen (PSMA) (HYNIC-Glu-Urea-A, 99mTc-PSMA) single photon emission computed tomography (SPECT)/computed tomography (CT) in the detection of significant residual prostate cancer after neoadjuvant ADT with the reference standard of postoperative pathology. Methods: A retrospective analysis of 154 prostate cancer patients treated in Fudan University Shanghai Cancer Center from March 2017 to July 2021 who underwent radical prostatectomy (RP) after neoadjuvant ADT was performed. All patients underwent preoperative mpMRI and 99mTc-PSMA SPECT/CT. Patients were divided into two groups according to the postoperative pathology: the significant residual group and complete response or minimum residual disease (CR/MRD) group. The clinical characteristics, the scores of Prostate Magnetic Resonance Imaging for Local Recurrence Reporting (PI-RR) system and the positive rate of 99mTc-PSMA SPECT/CT of the two groups were compared. The differences among the diagnostic efficacy of mpMRI and 99mTc-PSMA SPECT/CT alone and in combination were analyzed by the receiver operating characteristic (ROC) curve and the area under curve (AUC). Results: In total, the significant residual group consisted of 128 patients, and the CR/MRD group consisted of 26 patients. The average and median age of the patients were 66.88±7.79 (ranged from 47 to 85) years and 68 years, respectively. There was no statistical difference in age, PSA before neoadjuvant ADT and Gleason scores between the two groups, while PSA after neoadjuvant ADT of the significant residual group was significantly higher than that of the CR/MRD group. The AUC of mpMRI was 0.713, the sensitivity and specificity were 78.13% and 30.77%, respectively, with a cut-off of PI-RR score 3, while sensitivity and specificity were 68.75% and 69.23%, respectively, with a cut-off of PI-RR score 4. The AUC of 99mTc-PSMA SPECT/CT was 0.729, the sensitivity and specificity were 76.56% and 69.23%, respectively. The AUC of mpMRI combined with 99mTc-PSMA SPECT/CT was 0.809, which was significantly higher compared with the two alone (P<0.05). Conclusion: The combination of mpMRI and 99mTc-PSMA SPECT/CT can significantly improve the diagnostic efficiency for significant residual prostate cancer after neoadjuvant ADT. [ABSTRACT FROM AUTHOR]