In-vivo Evaluation eines computergestützten 3-D-Simulationsmodells zur interstitiellen Tumorablation an der Schweineleber unter normaler und unterbrochener hepatischer Perfusion

Abstract

Introduction: Treating liver tumors by in situ ablation techniques such as laser induced thermotherapy (LITT) creates thermal lesions with complex lesion geometry. The aim of this study was to develop and evaluate a computer-simulated 3-D irradiation model for predicting the thermal volume in LITT. Material and Methods: Light and heat distribution in the tissue was calculated by using a Monte Carlo simulation. We first established a tissue database (human/animal/healthy/tumorous, n = 120 samples). A 3-D image of the coagulation volume was created and the simulation results were correlated to those in vivo in 15 domestic pigs. The animals were randomized into three groups: normal hepatic perfusion; interrupted perfusion by Pringle maneuver; i.a. embolization by starch microspheres. Results: Simulating the coagulation volume required 28.5 (23 – 27) min. Simulated or in vivo interrupted perfusion led to a 4.5-fold (DSM) or 10-fold (Pringle) increase in lesion volume. The deviation in the diameter between the simulation and in vivo data was a maximum of 3.1% ± 0.3 ( LITT _mono ) , 2.6% ± 0.3 (LITT_Pringle ) and 15.6% ± ( LITT_DSM ). Conclusion: The developed 3-D irradiation model showed very good prediction of the coagulation volume in LITT. It is now possible for the first time to make a statement about the expected lesion geometry and the application parameters required for reliable tumor destruction during in situ ablation procedures.