Comparison of dosimetry models to predict outcome for radioembolization in patients with intermediate to advanced hepatocellular carcinoma.

BACKGROUND

Yttrium-90 (Y90) radioembolization is an effective locoregional therapy for hepatocellular carcinoma (HCC). However, the radiation dose determines the result of Y-90. This study aimed to compare the outcomes of two dosimetry methods of Y-90 resin microspheres (the body surface area model [BSA] and the partition model [PM]) and determine the radiation dose to predict prognosis.

METHODS

A retrospective cohort study was conducted in a single tertiary medical center in Taiwan. Between May 2016 to September 2019, 89 patients with intermediate to advanced HCCs were treated with Y90 resin microspheres and followed up for at least six months. Clinical data, laboratory profiles, dosimetric parameters, tumor response, and prognosis were collected and compared between BSA and PM. Univariate and multivariate survival analyses were performed to investigate whether the dosimetric model impacts prognosis.

RESULTS

The median overall survival (OS) was 15.8 months. The PM had significantly better OS than the BSA model (27.8 vs. 10.8 months, p = 0.011). The disease control rate in the seventh month was 40.9 % in PM and 31.1 % in BSA. There was no difference in the non-tumor and tumor doses between the two dosimetric groups. The independent prognostic factors are dosimetric method and total tumor volume scale (TTVS). Subgroup analysis for each dosimetry model showed improved OS in patients who received tumor doses over 125Gy (p = 0.040 for PM; p = 0.037 for BSA).

CONCLUSION

Y-90 radioembolization using the PM and tumor volume are associated with OS in patients with intermediate to advanced HCC.