03:09 PM Abstract No. 113 Lobar Yttrium-90 transarterial radioembolization equal or greater than 150Gy MIRD: an analysis of hepatic biochemical safety as a function of treated liver volume and administered dose

Abstract

Yttrium-90 transarterial radioembolization (TARE) is a safe procedure for the treatment of primary and metastatic hepatic malignancies. There is a strong suggestion that increased administered dose correlates with tumor response. While segmental TARE can preserve hepatic parenchyma, selective administrations are not always possible. Existing literature supports a Medical Internal Radiation Dose (MIRD) of 150Gy to a hepatic lobe using glass microspheres. The safety of doses >150Gy is not as well understood. The hepatic biochemical safety of lobar TARE at MIRD ≥150Gy was evaluated. Patients who underwent lobar TARE with glass microspheres for the treatment of liver malignancies at a MIRD of ≥150Gy with appropriate follow up at two academic centers from 2014 to 2018 were included. Multivariate linear regression models were used to evaluate differences in hepatic biochemical function and clinical scoring models at baseline and at 1 and 3 months following TARE as function of percent liver treated and dose. The occurrence of adverse events (CTCAE criteria) was also recorded. 23 patients were included in the study. 20 patients had primary hepatic malignancies (13 HCC and 7 ICC), and 3 had metastatic disease. 21 patients were Child Pugh (CP) A. Right lobar TARE was performed in 12 patients and left lobar TARE in 11 patients. The mean dose and target liver volume percentage was 234Gy (range 150-463) and 44% (range 13-75), respectively. Overall, there was no statistically significant change in sodium, INR, creatinine, albumin, Na-MELD, ALBI, or CP score at 1 and 3 months post TARE with doses ≥ 150Gy. The mean increase in Na-MELD was 4 (p=.005) and bilirubin was 0.4 (p=.04) at 1 month for patients receiving 200Gy demonstrated a mean increase in Na-MELD of 0.6 (p=.005) and bilirubin of 0.01 (p=.04). These correlations were not statistically significant at 3 months (also observed in the HCC cohort). There were 2 grade III CTCAE complications (pain and diarrhea). Lobar TARE with ≥150Gy MIRD using glass microspheres is not significantly associated with hepatic biochemical change in patients with preserved liver function at 3 months post treatment.