Technetium-99m labelled macroaggregated albumin arterial catheter perfusion scintigraphy: prediction of gastrointestinal toxicity in hepatic arterialchemotherapy

Gastrointestinal toxicity from hepatic arterial infusion (HAI) of floxuridi ne in patients with liver metastases is probably due to extrahepatic perfus ion or to partial escape of the drug from first-pass liver extraction. The aim of this study was to verify the role of technetium-99m-labelled macroag gregated albumin (Tc-99m-MAA) arterial catheter perfusion scintigraphy at t he beginning of each chemotherapy cycle in decreasing or preventing gastroi ntestinal toxicity. We studied 167 consecutive patients. On the basis of th e scintigraphic follow-up and the presence or absence of an intrahepatic ar teriovenous shunt (IHAVS), we classified our patients into the following gr oups: (1) FU+ hepatic distribution pattern (DP), comprising 29 patients wit h regular scintigraphic follow-up who showed the expected distribution patt ern at each control or a distribution pattern with transient alterations (e xtrahepatic escape) promptly reversed by the replacement of the catheter, A mong these 29 patients there was one case of gastrointestinal toxicity. (2) FU- hepatic DP, comprising 128 patients who were evaluated with Tc-99m-MAA only at the beginning of the first chemotherapy cycle, showed the expected distribution pattern and underwent HAI with no further scintigraphic evalu ation. Among these 128 patients there were 28 cases of gastrointestinal tox icity. (3) FU+ pulmonary DP, comprising three patients with abnormally elev ated pulmonary uptake (higher than 5%) and with regular scintigraphic follo w-up. There were two cases of gastrointestinal toxicity among these three p atients. (4) FU- pulmonary DP, comprising seven patients with abnormally el evated pulmonary uptake and without regular scintigraphic followup. There w ere four cases of gastrointestinal toxicity among these seven patients. The incidence of toxicity was significantly higher in group FU- hepatic DP tha n in group FU+ hepatic DP (21.9% vs 3.4%, P<0.05). In both the FU+ pulmonar y DP and FU- pulmonary DP groups, the incidence of gastrointestinal toxicit y was higher than 50%, with no significant difference between them. We conc lude that, when performing Tc-99m-MAA perfusion scintigraphy, the presence of an abnormally elevated pulmonary uptake (IHAVS higher than 5%) is the mo st relevant positive prognostic index for the development of gastrointestin al toxicity. Furthermore, in the absence of abnormal pulmonary uptake (IHAV S lower than 5%), strict scintigraphic follow-up is useful since it is able to promptly diagnose the presence of extrahepatic abdominal perfusion and thus to prevent the occurrence of gastrointestinal toxicity.