Evaluating local hepatocellular carcinoma recurrence post-transcatheter arterial chemoembolization: is diffusion-weighted MRI reliable as an indicator?
OBJECTIVE
To evaluate the detectability of local hepatocellular carcinoma (HCC) recurrence after transcatheter arterial chemoembolization (TACE) by diffusion-weighted MR imaging in correlation with those of gadolinium-enhanced MR imaging.


METHODS
Respiratory-triggered diffusion-weighted MR images (b factor, 500 s/mm(2); number of averaging, six were obtained in 25 patients with 39 HCCs. Two independent radiologists evaluated diffusion-weighted MR images, gadolinium-enhanced MR images after TACE, and assigned confidence levels for postoperative HCC recurrence. Apparent diffusion coefficients (ADCs) in HCCs were also measured. Sensitivities and specificities were compared using an extension of the McNemar test. Observer performance was also determined by ROC curve analysis.


RESULTS
Local recurrences in 14 HCCs and complete tumor necrosis in 25 HCCs after TACE were determined. Sensitivity for the detection of local HCC recurrence was higher on gadolinium-enhanced MR imaging (82%) than on diffusion-weighted MR imaging (60.7%) for the two readers in combination and separately (P < 0.05). Specificities were comparably high for both sequences. Az values were higher for gadolinium-enhanced MR images (0.92) than for diffusion-weighted MR images (0.74) for readers in combination and separately (P < 0.05). Mean ADC values showed an increase after TACE (P < 0.001).


CONCLUSIONS
Diffusion-weighted MR imaging was not found to be a reliable predictor of local HCC recurrence after TACE as compared with gadolinium-enhanced MR imaging.
Goshima
Satoshi
S
Department of Radiology, Gifu University Hospital, Gifu, Japan. gossy@par.odn.ne.jp
Kanematsu
Masayuki
M
Kondo
Hiroshi
H
Yokoyama
Ryujiro
R
Tsuge
Yusuke
Y
Shiratori
Yoshimune
Y
Onozuka
Minoru
M
Moriyama
Noriyuki
N
D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000628:therapy; D016461:Chemoembolization, Therapeutic; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D015588:Observer Variation; D012680:Sensitivity and Specificity
D003287:Contrast Media; D019786:Gadolinium DTPA