ISSN:
1435-604X
Keywords:
Photodynamic therapy
;
Diffusing fibre tips
;
Interstitial light delivery
;
Light dosimetry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Physics
,
Technology
Notes:
Abstract Optimal delivery of light to the tumour is of considerable importance in photodynamic therapy. The most effective way of delivering laser light to the tumour tissue is through an implanted optical fibre. In order to investigate the possible effects taking place at the tips of fibres implanted in tissue, fibres were used to deliver light to human blood and the transmission of light by the blood was measured at different power levels. The maximum power level which could be delivered without charring or coagulation at the fibre tip was measured for five different fibres. Three plane cut fibres and two with 1.5 cm long diffusing tips were studied. Charring and coagulation, which resulted in practically no light being delivered more than 0.5 mm from the fibre tip, were observed at relatively low-output powers (70-130 mW) for all the plane-cut fibres. This is less than the level required to deliver a clinically useful dose in a reasonable time. In contrast, neither charring nor coagulation was observed at the diffusing tips for output powers up to 1.1 W and consequently these should be the fibres of choice for interstitial photodynamic therapy. Observed changes in light transmission through the blood with increasing output power indicate that, for accurate light dosimetry, a means of monitoring delivered light in vivo during photodynamic therapy is essential.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02032609
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