Implementation of a spreadsheet program for calculation of equivalent square field size.

Equivalent square field size is a parameter widely used in calculations for external beam treatment planning. The algorithm and features of a spreadsheet program used to calculate the equivalent square, independently of the treatment planning system, are described. The program uses an approximation method based on the application of Lamé curves.

Design of a multiblock phantom for radiotherapy dosimetry applications.

This note describes the design of a multiblock semi-anatomic phantom, which lends itself to a variety of radiotherapy dosimetry applications, in particular, the audit of external beam treatment planning and delivery. The basic building blocks of the phantom were formed from a variety of tissue substitute materials and could be assembled in many ways to model different cross-sections through the body.

Use of Monte Carlo computation in benchmarking radiotherapy treatment planning system algorithms.

Radiotherapy treatments are becoming more complex, often requiring the dose to be calculated in three dimensions and sometimes involving the application of non-coplanar beams. The ability of treatment planning systems to accurately calculate dose under a range of these and other irradiation conditions requires evaluation. Practical assessment of such arrangements can be problematical, especially when a heterogeneous medium is used.

A therapy beam training aid.

Beams of X-rays and electrons used in external beam radiotherapy are characterized by differences in penetration, build-up, divergence, scatter etc. This short communication describes a very simple phosphor-loaded box that can be used to demonstrate directly to students the different properties of beams and the effect of field modifiers such as wedge filters, lead shields etc.

A model simulator for radiotherapy treatment planning and checking.

For a linear accelerator the direction and orientation of a beam is specified uniquely by a set of gantry, turntable and collimator angles. Sometimes, particularly for 3D planning, it is very difficult for the planner or plan checker to visualize the set-up of the treatment machine from the angles specified for each beam. This note describes a simple line-of-sight model that can be used for planning and checking the radiotherapy geometry prior to simulator verification.