Title

WE-G-16A-01: Evolution of Radiation Treatment Planning

Authors

Jacob Van Dyk, The University of Western OntarioFollow

Document Type

Article

Publication Date

5-2014

Journal

Medical Physics

Volume

41

Issue

6

First Page

515

Last Page

515

URL with Digital Object Identifier

http://dx.doi.org/10.1118/1.4889474

Abstract

When the World was Flat: The Two-Dimensional Radiation Therapy Era” - Jacob Van Dyk

In the 2D era, anatomy was defined with the aid of solder wires, special contouring devices and projection x-rays. Dose distributions were calculated manually from single field, flat surface isodoses on transparencies. Precalculated atlases of generic dose distributions were produced by the International Atomic Energy Agency. Massive time-shared main frames and mini-computers were used to compute doses at individual points or dose distributions in a single plane. Beam shapes were generally rectangular, with wedges, missing tissue compensators and occasional blocks to shield critical structures. Dose calculations were measurement-based or they used primary and scatter calculations based on scatter-air ratio methodologies. Dose distributions were displayed on line printers as alpha-numeric character maps or isodose patterns made with pen plotters.