Background and Aims
Chemoembolization is a standard treatment for hepatocellular carcinoma (HCC). Radioembolization with 90Y microspheres is a new, transarterial approach to radiation therapy. We performed a comparative effectiveness analysis of these therapies in patients with HCC.
Methods
We collected data from 463 patients who were treated with transarterial locoregional therapies (chemoembolization or radioembolization) over a 9-year period. We excluded patients who were not appropriate for comparison and analyzed data from 245 (122 who received chemoembolization and 123 who received radioembolization). Patients were followed for signs of toxicity; all underwent imaging analysis at baseline and follow-up timepoints. Overall survival was the primary outcome measure. Secondary outcomes included safety, response rate, and time-to-progression. Uni- and multi-variate analyses were performed.
Results
Abdominal pain and increased transaminase activity were more frequent following chemoembolization (P<.05). There was a trend that patients treated with radioembolization had a higher response rate than with chemoembolization (49% vs. 36%, P=0.104). Although time-to-progression was longer following radioembolization than chemoembolization (13.3 months vs 8.4 months, P=0.046), median survival times were not statistically different (17.4 months vs 20.5 months, P=0.232). Among patients with intermediate-stage disease, survival was similar between groups that received chemoembolization (17.5 months) and radioembolization (17.2 months, P=0.42).
Conclusion
Patients with HCC treated by chemoembolization or radioembolization with 90Y microspheres had similar survival times. Radioembolization resulted in longer time-to-progression and less toxicity than chemoembolization. Post-hoc analyses of sample size indicated that a randomized study with >1000 patients would be required to establish equivalence of survival times between patients given the different therapies.
Context
Response Evaluation Criteria in Solid Tumors [RECIST (unidimensional)], World Health Organization [WHO (bi-dimensional)] and European Association for Study of the Liver [EASL (necrosis)] guidelines are commonly used to assess response following therapy for hepatocellular carcinoma (HCC). No universally accepted standard exists.
Objectives
To evaluate intermethod agreement between these 3 imaging guidelines and to introduce the concept of the “primary index lesion” as a biomarker for response.
Design
Single-center comprehensive imaging analysis.
Setting and Participants
245 consecutive patients with HCC who were treated with chemoembolization or radioembolization between January 2000 and December 2008. Computed tomography and magnetic resonance imaging scans (N=1065) were reviewed to assess response in the “primary index lesion,” defined as the largest tumor targeted during first treatment.
Main Outcome Measures
Intermethod agreement (k statistics) between RECIST, WHO, and EASL guidelines response; correlation of WHO and EASL response in the primary index lesion with time to progression and survival.
Results
κ coefficients were 0.86(95% confidence interval [CI],0.80–0.92) between the WHO and RECIST guidelines, 0.24(95% CI, 0.16–0.33) between RECIST and EASL and 0.28 (95% CI, 0.19–0.36) between WHO and EASL. Disease progressed in 96 patients; 113 died. The hazard ratio for time to progression in responders compared with nonresponders was 0.36(95% CI, 0.23–0.57) for WHO, 0.38(95% CI, 0.24–0.58) for RECIST, and 0.38(95% CI, 0.22–0.64) for EASL. Hazard ratios for survival in responders compared with nonresponders in univariate and multivariate analyses were 0.46(95% CI, 0.32–0.67) and 0.55(95% CI, 0.35–0.84); they were 0.36(95% CI, 0.22–0.57) and 0.54(95% CI, 0.34–0.85) for EASL. Hazard ratios for survival in responders vs nonresponders in patients with solitary and multifocal HCC were 0.39 (95% CI, 0.19–0.77) and 0.51 (95% CI, 0.32–0.82) for WHO and 0.26 (95% CI, 0.10–0.67) and 0.47 (95% CI, 0.28–0.79) for EASL.
Conclusions
Among a group of patients with HCC, agreement for classification of therapeutic response was high between RECIST and WHO, but low between each of these and EASL. Application of these methods to measure response in a primary index lesion resulted in statistically significant correlations with disease progression and survival.
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