A practical method of measuring electron isodose curves using a linear detector array for validation of treatment...

A practical method of measuring electron isodose curves for validation of treatment planning system data using a linear detector array in a water phantom is described. The detector array was used to measure both the profile and depth dose data required. A depth-dependent correction was required, determined from a comparison with diode-measured depth dose. Application of this correction enabled accurate reconstruction of isodose curves. Isodose curves were also measured with diodes, to verify the array measurements. The two were found to be in good agreement. The advantage of the array-based method is a substantial saving in linear accelerator time when compared with point-by-point detector measurements. Although the data reproduced here are specific to the linear detector array of one manufacturer, the overall measurement technique is generally applicable.