Optimization of laser dosimetry based on patient-specific anatomical models for the ablation of pancreatic ductal adenocarcinoma tumor

Abstract

Laser-induced thermotherapy has shown promising potential for the treatment of unresectable primary pancreatic ductal adenocarcinoma tumors. Nevertheless, heterogeneous tumor environment and complex thermal interaction phenomena that are established under hyperthermic conditions can lead to under/over estimation of laser thermotherapy efficacy. Using numerical modeling, this paper presents an optimized laser setting for Nd:YAG laser delivered by a bare optical fiber (300 µm in diameter) at 1064 nm working in continuous mode within a power range of 2–10 W. For the thermal analysis, patient-specific 3D models were used, consisting of tumors in different portions of the pancreas. The optimized laser power and time for ablating the tumor completely and producing thermal toxic effects on the possible residual tumor cells beyond the tumor margins were found to be 5 W for 550 s, 7 W for 550 s, and 8 W for 550 s for the pancreatic tail, body, and head tumors, respectively. Based on the results, during the laser irradiation at the optimized doses, thermal injury was not evident either in the 15 mm lateral distances from the optical fiber or in the nearby healthy organs. The present computational-based predictions are also in line with the previous ex vivo and in vivo studies, hence, they can assist in the estimation of the therapeutic outcome of laser ablation for pancreatic neoplasms prior to clinical trials.

Optical signatures of thermal damage on ex-vivo brain, lung and heart tissues using time-domain diffuse optical spectroscopy

“…Moreover, in the case of thermal therapies, it is crucial to prevent tissue carbonization, which is harmful to the body [ 11 ]. Therefore planning and real-time control of the therapy are of paramount importance [ 12 ]. To control the treatment, current strategies employ thermometry, based on Magnetic Resonance Imaging [ 13 ] or on contact sensors.…”

Theoretical and Experimental Analysis of the Effect of Vaporization Heat on the Interaction between Laser and Biological Tissue

“…It indicated high accuracy for estimating temperature. Pouya et al [8] established a model to optimize the laser dosimetry for the ablation of pancreatic ductal adenocarcinoma tumors. Their computational model is based on Pennes' bioheat model, and the latent heat of water is added together with the water content as an extra heat source.…”