Prediction of aggressiveness of prostate cancer using MR spectroscopy at ultra-high magnetic field

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15591275
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Kobe University
• Principal Investigator: KAJI Yasushi Kobe University, Hospital, Assistant Professor, 医学部附属病院, 講師 (10273947)
• Co-Investigator(Kenkyū-buntansha): SUGIMURA Kazuro Kobe University, Graduate School of Medicine, Professor, 大学院・医学系研究科, 教授 (00136384) ; FUJII Masahiko Kobe University, Hospital, Associate Professor, 医学部附属病院, 助教授 (00228959) ; KAMIDONO Sadawo Kobe University, Graduate School of Medicine, Professor(director), 大学院・医学系研究科, 教授(理事) (30030935) ; KURODA Kagayaki Tokai University, School of Information Technology and Electronics, Associate Professor, 電子情報学部, 助教授 (70205243)
• Project Period (FY): 2003 – 2004
• Keywords: prostate cancer / ultra-high magnetic field / MR spectroscopy

Research Abstract

In 2003, 5 patients with biopsy proved prostate cancer were included in this study. MR images and MR spectra were obtained using 3 tesla MR unit. In 4 of 5 patients, spectra could not be evaluated because of poor quality due to post-biopsy prostate hemorrhage.
Elimination of rectal gas and prostate hemorrhage was needed to keep magnetic field homogeneity. MR examination was performed before prostate biopsy, and using a purgative the day before the MR examination in 2004 study.
High quality spectra were obtained in 25 of 51 patients (50%). It was presumed that one of the reasons of low successful rate was inhomogeneous radiofrequency (RF) excitation of whole prostate. In 25 patients, the (choline + creatine) / citrate peak area ratio (CC/C) was calculated after spectroscopic acquisition. The mean CC/C was 1.94 in peripheral zone (PZ) cancer, and 0.46 in healthy PZ (p<0.0001). In transition zone (TZ), the mean CC/C was 1.84 in cancer, and 1.03 in healthy TZ.
The limitation of this study was low successful examination rate, but the spectral quality in patient with successful RF excitation was superior to usual spectrum at 1.5 tesla. When the RF excitation method is improved completely, significantly important metabolite information is produced using ultra-high MR unit.