In 1973 I programmed for the oncology department at L.A. County/US Medical Center. We had a Varian Clinac linear accelerator with computer-readable and -drivable motors. The clinicians would manually position the Clinac (with the patient on it) for the first treatment, and the position would be saved in the patient's computerized file and restored on subsequent treatments.
For some treatments, a metal wedge would be placed within the beam to attenuate it more at the thick end of the wedge.
Because of the non-linear attenuation along the length of the physical metal wedge, dosages were difficult to calculate.
Someone got the bright idea of creating a software wedge by slowly moving the treatment couch at the same time as closing the beam aperture, so that there would be 100% exposure at one end of the "wedge" and 0% at the other, with a linearly decreasing distribution across the whole wedge.
I was the programmer for this project, and we had just started testing it with a sheet of X-ray film on the couch when I received an offer I couldn't refuse to go work elsewhere.
I'm glad that I departed before they started using this on live patients.
For some treatments, a metal wedge would be placed within the beam to attenuate it more at the thick end of the wedge. Because of the non-linear attenuation along the length of the physical metal wedge, dosages were difficult to calculate.
Someone got the bright idea of creating a software wedge by slowly moving the treatment couch at the same time as closing the beam aperture, so that there would be 100% exposure at one end of the "wedge" and 0% at the other, with a linearly decreasing distribution across the whole wedge.
I was the programmer for this project, and we had just started testing it with a sheet of X-ray film on the couch when I received an offer I couldn't refuse to go work elsewhere.
I'm glad that I departed before they started using this on live patients.