Temperature monitoring and lesion volume estimation during double-applicator laser-induced thermotherapy in ex vivo swine pancreas: a preliminary study
- 269 Downloads
Tissue temperature distribution plays a crucial role in the outcome of laser-induced thermotherapy (LITT), a technique employed for neoplasias removal. Since recent studies proposed LITT for pancreatic tumors treatment, assessment of temperature and of its effects around the laser applicator could be useful to define optimal laser settings. The aims of this work are temperature monitoring and measurement of ablated tissue volume in an ex vivo porcine pancreas undergoing double-applicator LITT. A three-dimensional numerical model is implemented to predict temperature rise and volumes of ablated tissue in treated pancreas. Experiments are performed to validate the model, with two modalities: (1) 12-fiber Bragg grating sensors are adopted to monitor the heating and cooling during LITT at several distances from the applicators tip, and (2) 1.5-T MR imaging is used to estimate the ablated volume. Experimental data agree with theoretical ones: at 2 mm from both applicators tips, the maximum temperature increase is approximately 60 °C downward from the tips, while it increases of about 40 °C and 30 °C, respectively, at the level and upward from the tips. This behavior occurs also at other distances, proving that the tissue downward from the tip is mostly heated. Furthermore, the estimated volume with MRI agrees with theoretical one (i.d., 0.91 ± 0.09 vs. 0.95 cm3). The encouraging results indicate that the model could be a suitable tool to choose the optimal laser settings, in order to control the volume of ablated tissue.
KeywordsLaser-induced thermotherapy Pancreas cancer Laser–tissue interaction Fiber optic sensors
The authors would like to thank ITAL GM srl for the precious support provided.
Conflicts of interest
The authors declare that they have no conflicts of interest.
- 1.Vogl TJ, Müller P, Weinhold N, Hummerstingl R, Mack MG, Böttcher H, Philipp C, Felix R (1995) MR-guided laser-induced thermotherapy (LITT) of liver metastases. In: Müller G, Roggan A (eds) Laser-induced interstitial thermotherapy. SPIE–The International Society for Optical Engineering, WashingtonGoogle Scholar
- 8.Niemz MH (2004) Laser-tissue interactions: Fundamentals and application, 3rd edn. Springer, Berlin, pp 15–18Google Scholar
- 9.Di Matteo FM et al (2012) US-guided Nd:YAG laser ablation in porcine pancreatic tissue: an ex vivo study and numerical simulation. Paper 1297200. Presented at the Digestive Disease Week, San Diego, 19–22 May 2012Google Scholar
- 12.Müller G, Roggan A (1995) Laser-induced interstitial thermotherapy. SPIE Press, BellinghamGoogle Scholar
- 13.Gottschalk W (1992) Ein Meβverfahren zur Bestimmung der optischen Parameter biologischer Gewebe in vitro. Dissertation 93 HA 8984, Universitat Fridericiana Karlsruhe, KarlsruheGoogle Scholar
- 15.Rao YJ (2000) Fiber Bragg grating sensors: Principles and applications. In: Grattan KTW, Meggitt BT (eds) Optical fiber and sensor technology: Fundamentals. Kluwer Academic, Dordrecht, pp 355–380Google Scholar
- 16.BIPM (2008) Evaluation of measurement data—guide to the expression of uncertainty in measurement. JCGM 100:2008. BIPM, SèvresGoogle Scholar
- 17.Ding Y, Chen N, Chen Z, Pang F, Zeng X, Wang T (2010) Dynamic temperature monitoring and control with fully distributed fiber Bragg grating sensor. Proc SPIE 7634:1–6Google Scholar