Indocyanine green plasma clearance rate and 99mTc-galactosyl human serum albumin single-photon emission computed tomography evaluated preoperative remnant liver

Figure 1 Calculation of remnant liver indocyanine green plasma clearance rate. A: 3D volume analysis using SYNAPSE VINCENT^®, remnant liver anatomical volume rate: 53%; B: A 99mTc-galactosyl human serum albumin single-photon emission computed tomography (99mTc-GSA SPECT) image; C: A fused 99mTc-GSA SPECT and 3D volume analysis (using SYNAPSE VINCENT^®) image, remnant liver functional volume rate: 65%. The remnant liver indocyanine green plasma clearance rate (KICG) is calculated as follows: A-rem-KICG = remnant liver anatomical volume rate × KICG and functional volume remnant KICG (f-rem-KICG) = remnant liver functional volume rate × KICG. In this case of a right hepatectomy, a-rem-KICG = 0.53 × 0.087 = 0.047, f-rem-KICG = 0.65 × 0.087 = 0.057.

Figure 2 Anatomical volume remnant indocyanine green plasma clearance rate and functional volume remnant indocyanine green plasma clearance rate. A: Changes in anatomical volume remnant indocyanine green plasma clearance rate (a-rem-KICG) and functional volume remnant indocyanine green plasma clearance rate (f-rem-KICG) between pre- and post-portal vein embolization. The increased amount of f-rem-KICG was significantly larger than that of a-rem-KICG (P = 0.0273); B: Scatter plots of a-rem-KICG and f-rem-KICG. The black and white dots show the pre-and post-portal vein embolization (PVE) remnant liver KICGs, respectively. After PVE, 17 patients had a-rem-KICG > 0.05, and f-rem-KICG > 0.05. Six patients (26%) had a-rem-KICG < 0.05, and f-rem-KICG > 0.05. A significant correlation was observed between a-rem-KICG and f-rem-KICG (P = 0.0002, R² = 0.5156). a-rem-KICG: Anatomical volume remnant indocyanine green plasma clearance rate; f-rem-KICG: Functional volume remnant indocyanine green plasma clearance rate; PVE: Portal vein embolization.

Figure 3 The new decision tree for hepatectomy in our institution. First, the anatomical volume remnant indocyanine green plasma clearance rate (a-rem-KICG) is calculated. If the a-rem-KICG is < 0.05, 99mTc galactosyl human serum albumin single-photon emission computed tomography is performed and functional volume remnant KICG (f-rem-KICG) calculated. Portal vein embolization and reassessment are performed if the a-rem-KICG and f-rem-KICG are both < 0.05. CT: Computed tomography; ICG: Indocyanine green; a-rem-KICG: Anatomical volume remnant indocyanine green plasma clearance rate; 99mTc-GSA SPECT: 99mTc galactosyl human serum albumin single-photon emission computed tomography; f-rem-KICG: Functional volume remnant indocyanine green plasma clearance rate; PVE: Portal vein embolization.