J. Eichler et al., Temperature distribution for combined laser hyperthermia-photodynamic therapy in the esophagus, MED ENG PHY, 22(4), 2000, pp. 307-312
In recent years photodynamic laser therapy (PDT) has been tested in animal
and clinical studies for treatment of esophageal cancer. In several animal
experiments a synergistic effect was found by simultaneously applying PDT a
nd hyperthermia (HT). In this paper an optical fibre system is described wh
ich can be used in the esophagus for combined PDT with a 1 W dye laser and
HT with a 15 W Nd:YAG laser. A phantom was built simulating the geometry of
the esophagus using cow muscle. The spatial temperature field during HT wa
s measured Versus irradiation time. The results were compared with calculat
ions using a coupled Monte Carlo laser transport/finite difference heat tra
nsport model using the LATIS computer program. Measurements and calculation
s yield a realistic description of the temperature distribution during HT u
nder various experimental conditions. The LATIS program allows the predicti
on of the effects of blood perfusion for in vivo situations. The results sh
ow that perfusion has considerable influence on the temperature field, redu
cing the effective depth in tissue for HT. (C) 2000 IPEM. Published by Else
vier Science Ltd, All rights reserved.