title: Usefulness of proton magnetic resonance spectroscopy in predicting positive biopsy after high-intensity focused ultrasound for treatment of localized prostate cancer.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Urology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Muto
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Kaminaga
authors.forename: Akira
authors.initials: A
authors.lastname: Horiuchi
authors.forename: Kousuke
authors.initials: K
authors.lastname: Kitamura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Saito
authors.forename: Shuji
authors.initials: S
authors.lastname: Isotani
authors.forename: Raizo
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Ide
authors.forename: Shigeru
authors.initials: S
authors.lastname: Furui
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horie
mesh_terms: D000368:Aged; D001706:Biopsy; D006801:Humans; D008297:Male; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000628:therapy; D066244:Proton Magnetic Resonance Spectroscopy; D012189:Retrospective Studies; D036761:Ultrasound, High-Intensity Focused, Transrectal
keywords: T2-weighted; high-intensity focused ultrasound; prostate biopsy; prostate cancer; proton magnetic resonance spectroscopy