In Vivo Light Dosimetry In Interstitial Photodynamic Therapy

Abstract

A non-invasive isotropic fibre optic probe has been developed and used to determine the penetration depth of 630nm light in tumours of rats and a human patient during interstitial photodynamic therapy. The mean penetration depth of the light and standard error of the mean measured was 1.62 ± 0.18mm for a series of eight animal tumours and 1.99 ± 0.51mm in three human tumour nodules. The apparent penetration depth as observed from the area of illuminated skin at a distance from the tumour was also measured and its relevance to the light dosimetry discussed.