Objectives: To investigate the clinical effectiveness of proton magnetic resonance spectroscopy in predicting local recurrence or residual disease after high-intensity focused ultrasound for treatment of localized prostate cancer.
Methods: The present study included patients with localized prostate cancer who underwent high-intensity focused ultrasound of whole-gland ablation as primary therapy. Clinicopathological variables including proton magnetic resonance spectroscopy, T2-weighted magnetic resonance imaging, and prostate-specific antigen and its derivatives were analyzed to predict the positive prostate biopsy results using univariate and multivariate analyses. Furthermore, the presence of tumor in each of the 12 prostate sectors by T2-weighted magnetic resonance imaging and proton magnetic resonance spectroscopy were evaluated and compared with prostate biopsy results in each of the 12 prostate sectors in order to evaluate the local cancer distribution in the prostate after high-intensity focused ultrasound.
Results: Overall, we carried out 85 prostate biopsies in 52 patients. Multivariate logistic regression analysis showed that the positive finding of proton magnetic resonance spectroscopy was the only statistically significant prognostic parameter of pathological tumor progression in patients after high-intensity focused ultrasound. Prostate biopsy cores were obtained from 952 prostate sectors of 52 patients and 85 prostate biopsies. Compared with T2-weighted magnetic resonance imaging, proton magnetic resonance spectroscopy (sensitivity 52.8%, specificity 97.4%, positive predictive value 44.2% and negative predictive value 98.1%, P < 0.001) has higher values to predict local tumor progression in prostate sectors after high-intensity focused ultrasound.
Conclusions: Proton magnetic resonance spectroscopy is a useful, non-invasive diagnostic modality that predicts local tumor progression in patients after high-intensity focused ultrasound, as well as local cancer distribution at each of the prostate sectors with pinpoint accuracy.
Keywords: T2-weighted; high-intensity focused ultrasound; prostate biopsy; prostate cancer; proton magnetic resonance spectroscopy.
© 2014 The Japanese Urological Association.