A comparison of lung depth measured in the DRRs of breast tangential fields with the corresponding volume of lung receiving high doses in the DVHs of CT planned Ca Breast patients.
K. Walsh, J. Pettingell, H. Kerr, A. Eve, B. Mzenda, P. Peters, N. McAndrew, M. Robb, S. Razaq, A. Penny.
In breast radiotherapy it is often necessary to reduce field borders (compromising coverage) to reduce the volume of lung receiving high doses. Traditionally this decision has been based on the “centimetres of lung in the field”, with centres imposing a limit of between 2cm and 3cm of “Central Lung Depth” (CLD). With the development of 3D planning systems it is now possible to determine full volumetric dose information for the lung, and as several authors have commented[2,3,4] it is reasonable to expect that this would be a better indicator of potential radiation induced side affects. The difficulty in clinical practice is that the majority of experience is based on CLD and so this study seeks to determine whether a correlation between CLD and volumes of lung receiving high doses can be found.