The implementation of a generalised Batho inhomogeneity correction for radiotherapy planning with direct use of CT numbers.

A method for performing inhomogeneity corrections using a generalised Batho equation is described. The corrections are performed using the quantitative anatomical data produced by a CT scanner. The generalised Batho equation has been implemented on an EMIPLAN 7000 interactive treatment planning system. Details are given of the acquisition of the required data from the CT scan and from the existing stored beam data of the therapy machines.