Transition zone prostate cancer: metabolic characteristics at 1H MR spectroscopic imaging--initial results.
OBJECTIVE
To determine whether cancers of the prostate transition zone (TZ) possess a unique metabolic pattern by which they may be identified at proton magnetic resonance (MR) spectroscopic imaging.


METHODS
Findings in 40 patients who underwent combined endorectal MR imaging and hydrogen 1 MR spectroscopic imaging before radical prostatectomy and who had TZ tumor identified subsequently at step-section pathologic analysis were retrospectively reviewed. Within this population, a subset of 16 patients whose TZ tumor had a largest diameter of 1 cm or greater and was included in the MR spectroscopic imaging excitation volume was identified. In these 16 patients, the ratios of choline-containing compounds (Cho) and creatine/phosphocreatine (Cr) to citrate (Cit) (ie, [Cho + Cr]/Cit), Cho/Cr, and Cho/Cit were compared in tumor and control tissues. The presence of only Cho and the absence of all metabolites were also assessed.


RESULTS
The mean values of (Cho + Cr)/Cit, Cho/Cr, and Cho/Cit were different between TZ cancer and control tissues (P =.001, P =.003, and P =.001, respectively; Wilcoxon signed rank test). Nine (56%) of 16 patients had at least one tumor voxel in which Cho comprised the only detectable peak, while no control voxels showed only Cho (P =.008, McNemar test). The percentage of voxels in which no metabolites were detected did not differ between tumor and control tissues (P =.134, McNemar test).


CONCLUSIONS
TZ cancer has a metabolic profile that is different from that of benign TZ tissue; however, the broad range of metabolite ratios observed in TZ cancer precludes the use of a single ratio to differentiate TZ cancer from benign TZ tissue.
Zakian
Kristen L
KL
Departments of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA. zakiank@mskcc.org
Eberhardt
Steven
S
Hricak
Hedvig
H
Shukla-Dave
Amita
A
Kleinman
Shanon
S
Muruganandham
Manickam
M
Sircar
Kanishka
K
Kattan
Michael W
MW
Reuter
Victor E
VE
Scardino
Peter T
PT
Koutcher
Jason A
JA
D002794:Choline / Q000032:analysis; D019343:Citric Acid / Q000032:analysis; D003401:Creatine / Q000032:analysis; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010725:Phosphocreatine / Q000032:analysis; D011467:Prostate / Q000737:chemistry / Q000473:pathology; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies
D010725:Phosphocreatine; D019343:Citric Acid; D003401:Creatine; D002794:Choline