Irene Bargellini MD, Presenter: Nothing to Disclose

Roberto Cioni MD, Abstract Co-Author: Nothing to Disclose

Elena Bozzi MD, Abstract Co-Author: Nothing to Disclose

Antonio Cicorelli, Abstract Co-Author: Nothing to Disclose

Daniela Campani MD, Abstract Co-Author: Nothing to Disclose

Carlo Bartolozzi MD, Abstract Co-Author: Nothing to Disclose

Franco Filipponi MD, Abstract Co-Author: Nothing to Disclose

To retrospectively analyze CT accuracy in assessing tumor response after transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC), compared to histopathology results after transplantation.

CT images were retrospectively reviewed of 178 HCC patients (M/F=155/23; mean age 55.8±6.3 years), who were transplanted after TACE (conventional technique in 156 cases, drug-eluting beads (DEB)-TACE in 22 patients) from January 1996 to December 2010. Image analysis was performed by two independent readers, blinded to pathological data. Inter- and intra-observer agreement was calculated. Tumor response was assessed according to the modified RECIST criteria and compared to pathological tumor necrosis, that was classified as 100%, 90-99%, 50-90%, <50% and 0%.

At CT, the objective response rate was 77.5%, with 48.3% CR (86/178 patients), 29.2% PR (52/178 patients), 12.9% SD (23/178 patients) and 9.6% PD (17/178 patients). A good intra- (k=0.75 and 0.86) and interobserver (k=0.81) agreement was observed. Out of a total of 302 HCC nodules (mean size 24.6 ±14.5 mm, range 10-80mm) detected at CT and confirmed at pathology, 157 lesions (52%) were considered completely necrotic at CT. Sensitivity, specificity, PPV and NPV in detecting complete necrosis at CT were 87.5%, 68.9%, 62.4%, 90.3%, respectively, with 75.8% diagnostic accuracy. In a patient-by-patient analysis, overall agreement between CT and pathology was obtained in 119 patients (66.9%), with 20 cases (11.2%) of underestimation and 39 cases (21.9%) of overestimation of tumor response at CT. These results were not significantly influenced by variables such as TACE-OLT interval, CT-OLT interval, TACE technique and CT equipment. The majority of overestimations (26/39, 66.7%) consisted of patients classified as CR, who presented minimal residual viable tumor (>90% necrosis) at pathology.

Modified RECIST criteria assessed at CT after TACE are reproducible and reliable, although minimal overestimation of tumor response can occur.

Modified RECIST criteria and CT can reliably assess tumor response after TACE

Bargellini, I, Cioni, R, Bozzi, E, Cicorelli, A, Campani, D, Bartolozzi, C, Filipponi, F, Tumor Response after Transarterial Chemoembolization: CT-Pathologic Correlation in 178 Liver Explants.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009423.html