Paris system for interstitial brachytherapy

Abstract

The Paris System is a complete dosimetric system which greatly facilitates brachytherapy, using iridium 192 sources at low, pulsed or high dose-rate. The aim of this chapter is to present briefly the part of the system dedicated to interstitial brachytherapy. After a short description of the sources which can be used, the three basic principles of the Paris System are presented together with its particular mode of dose specification within the implanted volume, and the fixed value of the Reference Isodose (RI) equal to 85% of the Basal Dose-rate (BD), representative of the arithmetic mean of the minimal dose-rates in the central region of the implant. The method to calculate the treatment time is given. Simple relationships which can be used to predict the minimal dimensions of the treated volume (volume encompassed by the RI) at the very moment of the implant are presented. © 2009 Springer Science + Business Media B.V.