Contrôles de qualité pour les traitments de la prostate par curiethérapie à haut débit de dose

Prostate cancer can be treated by high dose rate brachytherapy, which consists of inserting of a radioactive source in the prostate volume using catheters through the perineum. The source stops at different positions during predetermined times depending on the volume treated, the position of the catheters and the physician's prescription. Therefore, the tumor site is treated by the inside, which decreases the level of secondary effects due to the treatment because healthy tissues are less irradiated. This work studies quality assurance procedures for prostate high dose rate brachytherapy. A quality assurance procedure is an independent method to check if the treatment is delivered as planified. The quality checks are important whatever the treatment technique because those have a direct impact on the secondary effect level and the survival of the patients. In prostate high dose rate brachytherapy, the quality checks are more important; the source is very close to the tumor site and the treatment dose for one fraction is equivalent to a dose of several fractions of external beam radiotherapy. This work presents three quality checks for prostate high dose rate brachytherapy: the study of the normalized time, the calculation of a point dose, and the real dose delivered during a treatment of prostate high dose rate brachytherapy.