title: Tumour-to-normal uptake ratio of 90Y microspheres in hepatic cancer assessed with 99Tcm macroaggregated albumin.
abstract: The selective delivery of a high dose of radiation to malignant hepatic tumours by infusion of non-biodegradable yttrium-90 (90Y) microspheres via the hepatic artery while sparing the non-tumorous liver parenchyma depends on the tumour-to-normal uptake ratio (T/N) of the therapeutic radiopharmaceutical. Using intrahepatic arterial technetium-99m macroaggregated albumin (99Tcm-MAA), the effect of tumour type, tumour vascularity assessed by hepatic angiography (HAG), tumour size and the degree of extrahepatic shunting on the T/N was investigated in 377 patients with hepatocellular carcinoma (HCC) and 25 patients with colorectal liver metastases. HCC was shown to have a wider range of T/N (0.2-26.5) compared with liver metastases (2.3-7.2). HCC with vascularity grade 1 on HAG had significantly lower T/N but there was no significant difference in HCC with higher vascularity grades. This confirmed that vascularity on HAG does not predict T/N. Overall there was no correlation between T/N and tumour size. Large tumours (> 20 cm) had a significantly lower T/N, probably due to necrosis in the tumour centres. A decrease in mean T/N with increasing percentages of lung shunting was observed in HCC. Determination of T/N by simulation with 99Tcm-MAA is recommended before internal radiation therapy with 90Y microspheres.
authors.affiliation: Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
authors.forename: S
authors.initials: S
authors.lastname: Ho
authors.forename: W Y
authors.initials: WY
authors.lastname: Lau
authors.forename: T W
authors.initials: TW
authors.lastname: Leung
authors.forename: M
authors.initials: M
authors.lastname: Chan
authors.forename: K W
authors.initials: KW
authors.lastname: Chan
authors.forename: W Y
authors.initials: WY
authors.lastname: Lee
authors.forename: P J
authors.initials: PJ
authors.lastname: Johnson
authors.forename: A K
authors.initials: AK
authors.lastname: Li
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging*; D015179:Colorectal Neoplasms / Q000473:pathology; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000556:secondary; D008863:Microspheres; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes