MODELLING OF THE ACTION OF AN OPTICAL FIBRE IN PHOTODYNAMIC THERAPY TREATMENT, AND ASSISTANCE IN THE PLANNING OF SAID TREATMENT

摘要

The invention relates to a method (200) that provides assistance in the planning of a patient's treatment with photodynamic therapy, during which a pre-defined photosensitive substance must be administered to the patient and subsequently subjected to a light at a pre-determined wavelength by means of a number of optical fibres which can be inserted over an insertion length into the area to be treated according to a position in relation to a brachytherapy grid. The method comprises: the measurement (230) of the volume of the are to be treated by means of volume reconstruction on the basis of the digital processing of the contours entered directly on a series of digital images of the area to be treated; and subsequently, on the basis of the calculation of the number of optical fibres to be used, determination (250) of the position of the optical fibres in relation to the brachytherapy grid and the insertion length thereof, which optimise the match between a calculated total theoretical action volume and the measured volume of the area to be treated, said total theoretical action volume being calculated as a function of the position of each fibre and of an elementary theoretical action volume of a fibre corresponding to the volume of a cylinder having pre-determined action radius R and height corresponding to the insertion length of the fibre. The invention also relates to a method (100) for modelling the action radius of an optical fibre using a correlation of the measured volumes of actual necrotic areas following a plurality of clinical tests performed on different patients with theoretical volumes calculated on the basis of the same sets of parameters as those used in the clinical tests and of the elementary theoretical action volume of a fibre.