Assessment of hepatic functional regeneration after hepatectomy using ^99mTc-GSA SPECT/CT fused imaging

The liver itself regenerates after hepatectomy but little is known about how much hepatic function recovers during the regeneration. The liver uptake value (LUV), calculated from Tc-99m-labeled galactosyl-human-serum-albumin (^99mTc-GSA) SPECT/CT fused images, is reliable and useful for evaluating hepatic function. In this study, we evaluated the clinical usefulness of LUV for estimating hepatic functional regeneration after hepatectomy. We enrolled 95 patients who had undergone ^99mTc-GSA SPECT/CT tests before/on days 30 and 90 after hepatectomy. We determined the LUV from the ^99mTc-GSA SPECT/CT images and calculated the %LUV (post-operative LUV/preoperative LUV x 100). Based on surgical procedures and histopathological damage, we divided the study population into patients with severe (n=12) or non-severe fibrosis (n=33) who had undergone minor hepatectomy, and patients with severe (n=14) or non-severe fibrosis (n=36) having major hepatectomy. On the 90th post-hepatectomy day, five patients manifested liver failure; in these patients, we analyzed the co-relation between liver failure and the results of the liver function tests performed on day 30 after surgery. Although the %LUV reached 95.4 ± 12.2% in 30 days, in patients with severe fibrosis after major hepatectomy it remained below 90%. Patients having low %LUV (< 75%) and high serum bilirubin (> 2.0 mg/dl) at 30 days showed a relative risk of liver failure of 12.0 and 4.5 (p < 0.001 and p < 0.001), respectively. Although the %LUV recovered to about 95% in all patients within 30 days after the hepatectomy, in patients with severe fibrosis having major hepatectomy, the process of recovery was delayed. The %LUV corresponded to the quality of the liver function which emerged in a later post-hepatectomy phase. (author)