Precision Radiotherapy for Hepatocellular Carcinoma: Exploring the Clinical Utility of Functional Liver Avoidance Planning (FLAP).
[PURPOSE] We assessed the utility of functional liver avoidance planning (FLAP) to meet clinical constraints and reduce dose to functioning liver tissue.
- p-value p=0.05
APA
Yorke AA, Nyflot MJ, et al. (2026). Precision Radiotherapy for Hepatocellular Carcinoma: Exploring the Clinical Utility of Functional Liver Avoidance Planning (FLAP).. Practical radiation oncology. https://doi.org/10.1016/j.prro.2026.03.008
MLA
Yorke AA, et al.. "Precision Radiotherapy for Hepatocellular Carcinoma: Exploring the Clinical Utility of Functional Liver Avoidance Planning (FLAP).." Practical radiation oncology, 2026.
PMID
41941894
Abstract
[PURPOSE] We assessed the utility of functional liver avoidance planning (FLAP) to meet clinical constraints and reduce dose to functioning liver tissue.
[METHODS] Twenty patients (52-83 years, 6/20 female) with varying degrees of cirrhosis (Child-Pugh scores A5-B9) underwent [99mTc] sulfur colloid SPECT/CT imaging with generation of functional liver volumes (FLV) at 30%max thresholds, and FLV were co-registered onto planning CT scans. Half of patients received prior liver directed therapy (LDT). VMAT-SBRT (5 fx, 5 CP-A, 5 CP-B/C) conventional plans were optimized following ASTRO consensus guidelines and those that did not meet published functional liver dose constraints (FLV mean, FLV V20) were re-optimized for functional liver avoidance and scaled to the same target dose coverage. Scanning proton beam therapy (PBT) plans were similarly generated for hypo-fractionated regimens (15 fx, 5 CP-A, 5 CP-B/C). We characterized the associations between clinical characteristics and the probability of FLAP re-optimization and correlations with FLV dose reduction.
[RESULTS] SBRT conventional plans for CP-A patients met all clinical and functional liver dose constraints, while 40% of CP-B/C SBRT plans, 40% of CP-A PBT plans, and 80% of CP-B/C PBT plans required re-optimization for FLV dose constraints. Compared to conventional plans, FLAP replans achieved a median reduction of 13% (range: 2%-30%) in FLV mean dose and 4% (range: 1%-10%) in FLV V20. Increasing likelihood of prior LDT correlated with a decrease in FLAP re-optimization frequency (Spearman R -0.95, p=0.05). This is reflected in CP-A SBRT patients requiring fewer functional liver avoidance replans (80% prior LDT, 0% FLAP replans) compared to CP-B/C PBT patients (10% prior LDT, 80% FLAP replans).
[CONCLUSION] We successfully investigated the clinical utility of functional tissue avoidance in different groups of patients with HCC as a planning strategy to preserve liver function and mitigate hepatoxicity.
[METHODS] Twenty patients (52-83 years, 6/20 female) with varying degrees of cirrhosis (Child-Pugh scores A5-B9) underwent [99mTc] sulfur colloid SPECT/CT imaging with generation of functional liver volumes (FLV) at 30%max thresholds, and FLV were co-registered onto planning CT scans. Half of patients received prior liver directed therapy (LDT). VMAT-SBRT (5 fx, 5 CP-A, 5 CP-B/C) conventional plans were optimized following ASTRO consensus guidelines and those that did not meet published functional liver dose constraints (FLV mean, FLV V20) were re-optimized for functional liver avoidance and scaled to the same target dose coverage. Scanning proton beam therapy (PBT) plans were similarly generated for hypo-fractionated regimens (15 fx, 5 CP-A, 5 CP-B/C). We characterized the associations between clinical characteristics and the probability of FLAP re-optimization and correlations with FLV dose reduction.
[RESULTS] SBRT conventional plans for CP-A patients met all clinical and functional liver dose constraints, while 40% of CP-B/C SBRT plans, 40% of CP-A PBT plans, and 80% of CP-B/C PBT plans required re-optimization for FLV dose constraints. Compared to conventional plans, FLAP replans achieved a median reduction of 13% (range: 2%-30%) in FLV mean dose and 4% (range: 1%-10%) in FLV V20. Increasing likelihood of prior LDT correlated with a decrease in FLAP re-optimization frequency (Spearman R -0.95, p=0.05). This is reflected in CP-A SBRT patients requiring fewer functional liver avoidance replans (80% prior LDT, 0% FLAP replans) compared to CP-B/C PBT patients (10% prior LDT, 80% FLAP replans).
[CONCLUSION] We successfully investigated the clinical utility of functional tissue avoidance in different groups of patients with HCC as a planning strategy to preserve liver function and mitigate hepatoxicity.