Apparent diffusion coefficient: prostate cancer versus noncancerous tissue according to anatomical region.
OBJECTIVE
To evaluate diagnostic performance of apparent diffusion coefficient (ADC) in differentiating prostate cancer from noncancerous tissue according to anatomical region.


METHODS
In 47 patients with diffusion-weighted-MR (b-value, 0 and 1000 sec/mm2) on a 1.5 T unit, ADCs were measured in prostate cancer and in three noncancerous tissues (transitional zone, peripheral zone, and prostatic base). Diagnostic performance of ADC for differentiating cancer from noncancerous tissue was evaluated using receiver-operating-characteristics (ROC) analysis.


RESULTS
Mean ADC of prostate cancer (0.963x10(-3) mm2/s) was lower than those of all noncancerous tissues (P<0.001). In noncancerous tissue, ADC differed according to anatomical region (peripheral zone, 1.572x10(-3) mm2/sec; transitional zone, 1.441x10(-3) mm2/sec; prostatic base, 1.146x10(-3) mm2/sec) (P<0.01). ADC was lower in prostate cancer than in all noncancerous tissues in 34 (72%) patients. Area under the ROC curve for differentiating cancer from noncancerous tissue in prostatic base (0.725) was less than those for differentiating cancer from noncancerous tissue in peripheral (0.952) and transitional zones (0.906) (P<0.05). Sensitivity differed according to anatomical region (peripheral zone, 98%; transitional zone, 82%; prostatic base, 66%) (P<0.05).


CONCLUSIONS
Variable ADC in noncancerous tissue according to anatomical region may limit diagnostic performance of ADC for cancer detection.
Department of Radiology, Asan Medical Center, University of Ulsan, Seoul, South Korea.
Jeoung Hyun
JH
Kim
Jeong Kon
JK
Kim
Bum-Woo
BW
Park
Namkug
N
Kim
Kyoung-Sik
KS
Cho
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity