Lobar decrease in Tc-99m-GSA accumulation in hilar cholangiocarcinoma

Hilar cholangiocarcinoma can obstruct hepatic ducts and involve the portal veins. Both biliary stasis and decrease in portal venous flow are known to reduce Tc-99m-diethylenetriamine pentaacetic acid-galactosyl human serum al bumin (GSA) accumulation. The specific relationship between these pathologi cal conditions due to hilar cholangiocarcinomas and Tc-99m-GSA accumulation has never been clarified. Methods: Sixteen patients with hilar cholangioca rcinomas who underwent Tc-99m-GSA liver scintigraphy were reviewed. The rel ationship between significant decrease in Tc-99m-GSA accumulation and lobar biliary stasis, or decrease in the portal venous Row, was evaluated. Avera ge counts of region of interest placed in both right and left lobes were co mpared in the same transaxial SPECT section. Gaunt ratios of right and left lobes were calculated. Results: Significant lobar decrease in Tc-99m-GSA a ccumulation was observed in 6 of the 16 patients. Ipsilateral portal venous stenosis or obstruction was seen in all these 6 patients, whereas ipsilate ral portal venous stenosis or obstruction was seen in only 1 of the other 1 0 patients. Symmetric bile duct dilatation was seen in 13 patients, and asy mmetric bile duct dilatation was seen in 3. Lobar decrease in Tc-99m-GSA ac cumulation correlated well with decrease in ipsilateral portal venous flow (P < 0.0005). The count ratio was significantly reduced when unilateral por tal venous flow decreased (P < 0.05). Conclusion: Using Tc-99m-GSA liver sc intigraphy, we can predict lobar decrease in ipsilateral portal venous flow and monitor hepatic functional lateralities in patients with hilar cholang iocarcinomas.