Related Experiment Video
Updated: Aug 17, 2026

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
Published on: September 11, 2011
Inverse planning for x-ray rotation therapy: a general solution of the inverse problem
1Department of Medical Physics, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
Abstract:
Rotation therapy with photons is currently under investigation for the delivery of intensity modulated radiotherapy (IMRT). An analytical approach for inverse treatment planning of this radiotherapy technique is described. The inverse problem for the delivery of arbitrary 2D dose profiles is first formulated and then solved analytically. In contrast to previously applied strategies for solving the inverse problem, it is shown that the most general solution for the fluence profiles consists of two independent solutions of different parity. A first analytical expression for both fluence profiles is derived. The mathematical derivation includes two different strategies, an elementary expansion of fluence and dose into polynomials and a more practical approach in terms of Fourier transforms. The obtained results are discussed in the context of previous work on this problem.
Related Concept Videos
Angle of Twist: Problem Solving
Inverse Trigonometric Functions
Orthogonal Trajectories
Polar Coordinate System
Polar Coordinates: Problem Solving
Planes in Space

