The Use of Photogrammetry in Tissue Compensator Design
Wendel Dean Renner, Thomas Pacelli O’Connor, Sharad R. Amtey, P. Raghunath Reddi, Gustave K. Bahr, James G. Kereiakes · Radiology · 1977
The surface topography of a patient can be determined by photogrammetry before beginning radiotherapy. The source light of the therapy unit or simulator is used to project a grid pattern onto the patient, and this is then photographed together with control points consisting of miniature light bulbs mounted on a frame suspended from the wedge slot of the therapy machine. When the photograph is projected onto a graphics terminal for data entry into a computer, the three-dimensional topography of the patient's surface can be reconstructed as a two-dimensional matrix of discrete points. A computer algorithm can then design a tissue compensator to fit the individual patient.