Cutoff Values for Dose-liver Function Parameters to Prevent Radiation-induced Liver Disease in Advanced Hepatoma

Abstract

AIM:To retrospectively explore the cutoff values that predict radiation-induced liver disease (RILD) in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) in the main trunk and/or the first branch who had previously received singlephoton-emission computed tomography (SPECT)-based threedimensional conformal radiotherapy (3DCRT; SPECT-B-3DCRT) using Tc-99m-galactosyl human serum albumin (Tc-99m GSA). METHODS: Seventy-five HCC patients with PVTT underwent SPECT-B-3DCRT (total dose of 45 Gy/18 fractions) in the stopbreathing position with an error of ≤5 mm. SPECT allowed the minimum possible irradiation of the functional liver (FL). ChildPugh score deterioration (CPSD) by 2 (=RILD) or CPSD by 1 was scored within four months of completing SPECT-B-3DCRT. Receiver-operating characteristic (ROC) analysis of the outcomes RILD vs CPSD by 1 was conducted to determine the accuracy and cutoff values for FLV20Gy (percentage of FL volume receiving ≥20 Gy), F20Gy (GSA counts within the irradiated liver area receiving ≥20 Gy ×100/GSA counts in the whole liver), F20Gy/LHL15 (liver radioactivity counts at 15 min/heart plus liver radioactivity counts at 15 min), and F20Gy/total count ratio (liver radioactivity counts/liver plus total background radioactivity counts). RESULTS:The cutoff values and accuracy of FLV20Gy, F20Gy, F20Gy/ LHL15, and F20Gy/total count ratio were 26.4 and 0.826 (p=0.024), 30.2 and 0.913 (p=0.004), 37.7 and 0.913 (p=0.001), and 43.0 and 0.957 (p<0.001), respectively. CONCLUSION: An F20Gy/total count ratio of 43.0 is the most reliable cutoff value for preventing RILD.

Functional Liver Imaging in Radiotherapy for Liver Cancer: A Systematic Review and Meta-Analysis

“…Twenty-seven of them were excluded because they were case reports, number of patients less than five, had no available information or had already included the latest or most informative publication of the same research team . Finally, the remaining twenty articles met the meta-analysis or descriptive tables (3,5,6,9,10,(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55).…”

“…Two articles used different thresholds to defined functional liver, and compared dose differences between functional liver-sparing and conventional anatomical planning (41,50). Some studies were not included in the metaanalysis because they were incomplete (only mean value or percentage difference), and raw data were unavailable (44,49,53). When only one threshold was included from each study (the threshold which showed the maximum difference between conventional and functional liver-sparing planning), the f-MLD was decreased by: 1.0 Gy [95%CI: (-0.13, 2.13), I 2 = 0%] between functional liver-sparing and conventional anatomical planning (Figure 2A).…”

“…Four of the studies showed that functional liver imaging was statistically significant in predicting the endpoint of RILT, while no correlation was found with anatomic planning (9,44,53,54) (Table 2). Although the endpoints used to evaluate RILD were inconsistent across studies.…”

“…Although the endpoints used to evaluate RILD were inconsistent across studies. Seven studies evaluated RILT after functional liver-sparing planning-guided radiotherapy, six of which were prospective and one retrospective (6,44,48,(51)(52)(53)55) (Table 2B). A total of 180 patients were included, 111 had a baseline CTP score A, and the rest had score B or higher (55 patients), and one publication did not describe baseline liver function.…”