The relationship between the absorbed dose of yttrium-90 and tumor response in transarterial radioembolization for advanced hepatocellular carcinoma

LIN Biqian; WANG Xiaoning; LU Xianming; YU Rongqian

doi:10.3969/j.issn.1009-0460.2025.09.002

Abstract：Objective To investigate the utility of a technetium-99m-labeled large-particle polymerized human serum albumin(99m Tc-MAA)SPECT/CT-based dosimetry model for quantifying the actual absorbed dose(AAD)in patients with advanced hepatocellular carcinoma(HCC)who underwent transarterial radioembolization(TARE)with yttrium-90(90 Y)and to determine the critical value for predicting TRAE tumor response thresholds.Methods A prospective study was conducted on 67 patients with advanced HCC between January 2023 and May 2024,99m Tc-MAA liver penetration imaging was used to calculate the standard tumor-to-nontumoral liver ratio(sTNR1)before radioembolization and the sTNR2 after radioembolization based on tissue volume and radioactivity.corrected mTNR=γ radiation counts at ROIs of target liver tumors/γ radiation counts at ROIs of target liver tumors.The predicted absorbed dose(PAD)and actual tumor absorbed dose(AAD)after radioembolization was calculated before radioembolization based on the TNR.RECIST 1.1 criteria were used to assess treatment response.Patient deaths were recorded during the period up to July 2025.Results The mTNR1 was slightly lower than the sTNR1 value(tpaired=-7.791,P<0.001);however,the concordance between the two was very low,with a correlation coefficient of rho=0.106(P=0.289).By Spearman's correlation analysis,before radioembolization,mPAD(rho=-0.452,-0.432)and mAAD(rho=-0.415,-0.415)were significantly negatively correlated with the maximum tumor diameter and the volume of the target liver lesion(P<0.001).Forty-two patients achieved objective remission at 3 months after TARE(complete response or partial response on tumor evaluation).The objective remission group had higher mTNR1(3.12 vs.2.93,P=0.011),mPAD(106.50 Gy vs.87.91 Gy,P=0.016),and mTNR2(2.20 vs.1.50,P<0.001),and mAAD(100.50 Gy vs.72.50 Gy,P<0.001)than the no objective remission group.After further correction for relevant clinical factors,mTNR2(OR=2.012,95%CI=1.149-11.474,P=0.001)and mAAD(OR=1.059,95%CI=1.013-1.107,P=0.011)remained predictors of objective tumor remission.Receiver Operating Characteristic(ROC)curves showed that mTNR2 and mAAD predicted objective tumor remission with cut-off values of 2.015 and 75.47 Gy.During a median follow-up of 6.77 months,25 patients(37.31%)died.Kaplan-Meier curves showed that the median OS of patients with mAAD≥75.47 Gy was 6.97 months,which was longer than the median OS of patients with mAAD<75.47 Gy(5.13 months;Log-rank=9.059,P=0.003).Conclusion The mTNR calculated based on 99m Tc-MAA and 90Y SPECT/CT,as well as the derived dosimetric parameters PAD and AAD,can be used as predictors of TARE outcomes in patients with advanced hepatocellular carcinoma.When AAD was greater than 75.47 Gy,the overall survival time of patients was relatively prolonged.