Abstract
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Objectives To investigate whether baseline patient and tumor characteristics can predict that 99mTc-MAA-scan results will contraindicate 90Y-radioembolization as initially designed.
Methods A retrospective study was conducted of patients that underwent 99mTc-MAA-scan planning for radioembolization using 90Y resin microspheres between 2006 and 2015. Baseline tumor and patient characteristics were compared between the group of patients in which the results of 99mTc-MAA-scan led to contraindication of 90Y-radioembolization and the group that was treated as planned. Variables that carried an independent risk of resulting in contraindication because of high lung shunt fraction (LSF) or extrahepatic uptake (EHU) were identified by logistic regression analysis. The ability of these variables to predict contraindication was obtained.
Results A total of 532 patients (365 males) with hepatocellular carcinoma (n=217), cholangiocarcinoma (n=31) and liver metastases from colorectal cancer (n=142), neuroendocrine tumors (n=49), or other tumors (n=93) were identified. First 90Y-radioembolization was contraindicated in 48 patients as the result of the 99mTc-MAA-scan findings due to high LSF (n=29) or EHU (n=19). A association was found between vascular invasion (VI) and high LSF (OR 5,58[95%CI:2,56-12,2];p<0,01) as well as for secondary tumors (ST) (OR 3,6 [95%CI:1,75-7,39];p<0,01) and prior intraarterial chemotherapy (OR 2,3 [95%CI:1,06-4,9];p<0,01) for EHU. The negative predictive value for VI and high LSF was 97%, for ST and EHU was 99% and for both of them versus contraindication was 92%.
Conclusions The presence of vascular invasion and secondary tumors independently predicted a contraindication of 90Y-radioembolization based on the results of the 99mTc-MAA-scan. Nevertheless, the lack of strong discrimination power emphasizes the value of 99mTc-MAA-scan in the work-up of 90Y-radioembolization. The absence of either of them identifies a group of patients with very low risk of contraindication. However, the severity of complications encourage the use of 99mTc-MAA-scan.