BEAM PROFILES FOR X-RAY ROTATION THERAPY

Determining the beam configuration necessary to deliver a desired dose distribution with rotation therapy is equivalent to solving an integr al equation. The equation has been solved analytically for a handful o f dose distributions having specific radial variation and either rotat ional or reflective angular symmetry. In this work a numerical method for calculating beam profiles appropriate for producing distributions having arbitrary radial variation and angular symmetry of order l grea ter than or equal to 2 is presented. The accuracy of the technique is demonstrated by comparison with one of the few dose distributions for which an analytic solution exists, and the ability to produce both mor e general and conformal distributions is also shown. The problems of n egative intensity and scatter are discussed. (C) 1998 American Associa tion of Physicists in Medicine. [S0094-2405(98)01206-1].