Yttrium-90 Radioembolization via the Cystic Artery supplying Hepatocellular carcinoma

To investigate the safety and efficacy of yttrium-90 radioembolization via the cystic artery for treatment of hepatocellular carcinoma (HCC) adjacent to the gallbladder

Materials and Methods:

This retrospective, single-center study included all 17 radioembolization procedures performed for HCC perfused partially or completely by the cystic artery from April 2017 to February 2022. Patient demographics, cancer treatment history, and procedural details including the angiographic anatomical location of the radioembolization and administered dosage were reviewed through electronic medical records. All patients presented over 1, 3, 6 months following radioembolization. The Child-Pugh classification of the included patients was A5 to B8, with six patients (35%) with portal vein invasion. Adverse events based on clinical, biochemical and imaging data, tumor response, and time to progression were analyzed.

Results: Median tumor size was 67 mm (range, 34 – 204 mm) and median tumor size supplied by the cystic artery was 51 (range, 25 – 204 mm). Median dose to the tissue perfused by the cystic artery was 273 Gy (range, 121–467 Gy). Eight patients (47%) received radioembolization at the deep cystic artery, six (25%) at the distal feeder, two (12%) at the main cystic artery, and one (6%) at the superficial cystic artery. Three patients (18%) had benign biliary dilation on follow-up imaging, though total bilirubin levels were within normal limits. Twelve patients (71%) exhibited gallbladder wall thickening and enhancement on 1 month follow-up imaging; two had gallbladder wall thickening and enhancement only proximal to the radio-embolized tumor site, two at the fundus of the gallbladder, and the rest over the whole gallbladder. Four (23%) patients had clinically insignificant elevation of total bilirubin levels. There were no occurrences of acute cholecystitis warranting invasive intervention during six month follow-up. Follow-up imaging demonstrated complete response in five target tumors (29%) and partial response in nine (52%). There were no cases of target tumor progression for the tumors supplied by the cystic artery. However, two cases (12%) exhibited overall tumor progression by six month follow up.

Conclusion: Radioembolization of Y90 adjacent or proximal to the cystic artery may have an acceptable safety profile with good treatment response. Though a significant number of patients exhibited transient gallbladder wall thickening and enhancement on 1 month follow-up imaging, this resolved in later follow up and did not appear to be clinically significant.