Autoactivation of source dwell positions for HDR brachytherapy treatment planning

The most accurate classical dose optimization algorithms in HDR brachythera py strongly depend on an appropriate selection of source dwell positions wh ich fulfill user-defined geometrical boundary conditions which are relative to patient anatomy. Most anatomical situations, such as for prostate and h ead and neck tumors, are complex and can require geometries with 5-15 cathe ters with 48 possible dwell positions per catheter depending on the tumor v olume. The manual selection of dwell positions using visual checks by trial and error is very time consuming. This can only be improved by the use of a technique which automatically recognizes and selects the optimum dwell po sitions for each catheter. We have developed an algorithm, termed an autoac tivation algorithm, which improves implant planning by providing a facility for the necessary automatic recognition of HDR source dwell positions. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)00411- 9].