Nelson Salas Jr et al 2004 Phys. Med. Biol. 49 1609 doi:10.1088/0031-9155/49/9/002
Nelson Salas Jr1,2, Fabrice Manns1,2, Peter J Milne2,3, David B Denham2, Ahmed M Minhaj1,2, Jean-Marie Parel1,2 and David S Robinson4,5
Show affiliationsA therapeutic procedure to treat small, surface breast tumours up to 10 mm in radius plus a 5 mm margin of healthy, surrounding tissue using laser interstitial thermotherapy (LITT) is currently being investigated. The purpose of this study is to analyse and model the thermal and coagulative response of ex vivo fibro-fatty tissue, a model for breast tissue, during experimental laser interstitial thermotherapy at 980 nm. Laser radiation at 980 nm was delivered interstitially through a diffusing tip optical fibre inserted into a fibro-fatty tissue model to produce controlled heating at powers ranging from 3.2 to 8.0 W. Tissue temperature was measured with thermocouples placed at 15 positions around the fibre. The induced coagulation zone was measured on gross anatomical sections. Thermal analysis indicates that a finite sum of exponential functions is an approximate solution to the heat conduction equation that more accurately predicts the time-temperature dependence in tissue prior to carbonization (T < 100 °C) during LITT than the traditional model using a single exponential function. Analysis of the ellipsoid coagulation volume induced in tissue indicates that the 980 nm wavelength does not penetrate deep enough in fibro-fatty tissue to produce a desired 30 mm diameter (14.1 × 103 mm3) coagulation volume without unwanted tissue liquefaction and carbonization.
87.50.wp Therapeutic applications
Issue 9 (7 May 2004)
Received 15 September 2003
Published 1 April 2004
Nelson Salas Jr et al 2004 Phys. Med. Biol. 49 1609
J T Kuikka et al 1980 Phys. Med. Biol. 25 735
T Jacobsen 1996 Eur. J. Phys. 17 250
Frank Balzer et al 2006 Nanotechnology 17 984
A Shalchi and H Döring 2007 J. Phys. G: Nucl. Part. Phys. 34 859
Y Lin et al 2003 Plasma Phys. Control. Fusion 45 1013
V P Godbole et al 2005 Nanotechnology 16 1186
T H K Barron and T G Gibbons 1974 J. Phys. C: Solid State Phys. 7 3269
Jonathan Hare 2008 Phys. Educ. 43 572
Gerhard Baur et al 1998 J. Phys. G: Nucl. Part. Phys. 24 1657