title: Analytic evaluation of heterogeneity locations for external beam treatment planning.
abstract: A method has been developed to calculate depths of calculation points analytically in patient contours containing internal heterogeneities. In this method, each contour is approximated by a Fourier series comprising five to ten terms. Using this approximation, the intersections of a ray line with each contour are found as the solution of a transcendental equation. Once these intersections have been located, effective depths used in heterogeneity calculations can readily be calculated.
mesh_terms: D000465:Algorithms; D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D011879:Radiotherapy Dosage