Medical Physics -- September 2003 -- Volume 30, Issue 9, pp. 2368-2375

Are dose calculations during dose optimization in brachytherapy necessary?

Michael Lahanas, D. Baltas

(Received 1 October 2002; accepted 14 April 2003; published 22 August 2003)

We consider the problem of anatomy based dose optimization in brachytherapy. A calculation method for some objective functions and their derivatives is proposed which significantly reduces the number of required operations. The optimization in some cases, ignoring a preprocessing step, is independent of the number of sampling points. The idea is that some of the objectives and their derivatives used for dose optimization do not require the explicit calculation of dose values. Dose optimization with the new modified computation method for the objectives and derivatives is, depending on the number of sampling points, up to 100 times faster than the conventional method with dose calculation.

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