title: Measuring total liver function on sulfur colloid SPECT/CT for improved risk stratification and outcome prediction of hepatocellular carcinoma patients.
abstract: BACKGROUND
  Assessment of liver function is critical in hepatocellular carcinoma (HCC) patient management. We evaluated parameters of [(99m)Tc] sulfur colloid (SC) SPECT/CT liver uptake for association with clinical measures of liver function and outcome in HCC patients.
  
  
  METHODS
  Thirty patients with HCC and variable Child-Turcotte-Pugh scores (CTP A5-C10) underwent [(99m)Tc]SC SPECT/CT scans for radiotherapy planning. Gross tumor volume (GTV), anatomic liver volume (ALV), and spleen were contoured on CT. SC SPECT image parameters include threshold-based functional liver volumes (FLV) relative to ALV, mean liver-to-spleen uptake ratio (L/Smean), and total liver function (TLF) ratio derived from the product of FLV and L/Smean. Optimal SC uptake thresholds were determined by ROC analysis for maximizing CTP classification accuracy. Image metrics were tested for rank correlation to composite scores and clinical liver function parameters. Image parameters of liver function were tested for association to overall survival with Cox proportional hazard regression.
  
  
  RESULTS
  Optimized thresholds on SC SPECT were 58 % of maximum uptake for FLV, 38 % for L/Smean, and 58 % for TLF. TLF produced the highest CTP classification accuracy (AUC = 0.93) at threshold of 0.35 (sensitivity = 0.88, specificity = 0.86). Higher TLF was associated with lower CTP score: TLFA = 0.6 (0.4-0.8) versus TLFB = 0.2 (0.1-0.3), p < 10(-4). TLF was rank correlated to albumin and bilirubin (|R| > 0.63). Only TLF >0.30 was independently associated with overall survival when adjusting for CTP class (HR = 0.12, 95 % CI = 0.02-0.58, p = 0.008).
  
  
  CONCLUSIONS
  SC SPECT/CT liver uptake correlated with differential liver function. TLF was associated with improved overall survival and may aid in personalized oncologic management of HCC patients.
authors.affiliation: Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA. srbowen@uw.edu.|Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA. srbowen@uw.edu.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Bowen
authors.affiliation: Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Tobias R
authors.initials: TR
authors.lastname: Chapman
authors.affiliation: Department of Physics, University of Washington, 3910 15th Ave. NE, Seattle, WA, 98195, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Borgman
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Miyaoka
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Kinahan
authors.affiliation: Division of Gastroenterology, Department of General Internal Medicine, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA, 98195, USA.
authors.forename: Iris W
authors.initials: IW
authors.lastname: Liou
authors.affiliation: Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: George A
authors.initials: GA
authors.lastname: Sandison
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Hubert J
authors.initials: HJ
authors.lastname: Vesselle
authors.affiliation: Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Nyflot
authors.affiliation: Department of Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Box 356043, Seattle, WA, 98195, USA.
authors.forename: Smith
authors.initials: S
authors.lastname: Apisarnthanarax
keywords: Child-Pugh; HCC; Liver function; ROC; SPECT/CT; Sulfur colloid