The reconstruction and dose-rate calculation of radium needle implants.

A comprehensive computer program has been developed for carrying out the various tasks associated with radium needle implants. Data input for the program are obtained by digitizing an orthogonal pair of radiographs with an analogue tracing system. Corresponding needles in the two radiographs are automatically located, and the implant may be rotated to any desired position in three dimensional space, at the same time presenting a view of the rotation on a storage oscilloscope. Automatic determination of the mean plane of a planar implant is possible, and the dose-rate distribution may be calculated in any specified plane. A Paterson--Parker exposure rate calculation may be performed with a biological dose and treatment time correction incorporated. The program is written in Fortran and runs on a small interactive computer system.