A manual algorithm for computing dwell times for two-catheter endobronchial treatments using HDR brachytherapy

A method has been developed to permit the calculation of dwell times for endobronchial high dose rate (HDR) brachytherapy treatment using two catheters, without using a dedicated treatment planning system. Worksheets were developed to guide a user through manual calculations, and a computer program was written to automate the process. This empirical algorithm produces dose distributions that are clinically safe and reasonable. The total dwell times match those predicted by individually optimized distributions to within a few percent. The method has been used most frequently as a quality assurance check on optimized plans produced by a commercial treatment planning system, but it can serve as a back-up method should the commercial system fail. [Worksheets with example calculations may be retrieved using anonymous ftp from the American Institute of Physics, Electronic Physics Auxillary Publication Service (EPAPS).]