Intrahepatic cholangiocarcinoma: a dose threshold evaluation in those undergoing transarterial radioembolization

Background: To evaluate the relationship between dose to tumor and radiologic response in intrahepatic cholangiocarcinoma (ICC) patients undergoing transarterial radioembolization (TARE).Methods: Twenty-patients who underwent treatment for 26 tumors were retrospectively reviewed. Radiologic response at 3-month was evaluated and post yttrium-90 bremsstrahlung single photon emission computerized tomography computed tomography was evaluated to determine tumor dose. Other factors such as particle load and activity per particle were evaluated.Results: The mean tumor dose for those with progressive disease or stable disease, partial response, and complete response (CR) by EASL criteria for the glass cohort was 294 +/- 0, 465.4 +/- 292.4 and 951.8 +/- 666.5 Gy respectively (P=0.039). A receiver operating characteristic (ROC) curve analysis of tumor dose demonstrated an area under the curve (AUC) of 0.738 (P=0.038) with Youden-index analysis demonstrated a cutoff point of >541.7 Gy (sensitivity: 55.56%; specificity: 92.86%) for the glass cohort. Significantly longer survival was noted in those who achieved a CR [HR: 4.79 (95% CI: 1.41-16.25)] and those treated with glass as compared to resin [HR: 5.02 (95% CI: 1.23-20.55), P=0.025]. Of the 17 treatments in 13 patients which were done concomitantly with chemotherapy 7/17 (41.2%) required a delay in chemotherapy, however all patients reinitiated chemotherapy after a delay.Conclusions: There appears to be a relationship between tumor dose and radiologic response, with this study suggesting a target of >= 541.7 Gy being warranted in patients receiving treatment with glass microspheres.

Automated summary

There appears to be a relationship between tumor dose and radiologic response in intrahepatic cholangiocarcinoma patients undergoing transarterial radioembolization. The study suggests a target dose of >= 541.7 Gy for patients receiving treatment with glass microspheres.