Evaluation of dose-volume histogram parameters (V20 and mean dose) in lung cancer adaptive radiotherapy with design of composite lung volumes (ITV)

Abstract

Physiological respiratory motion is a challenge in external radiotherapy for lung tumors. In adaptive radiotherapy, changing position of the target volume should be reflected in the simulation procedure and taken into account in the design of volumes for CTV/PTV proper coverage. This may be achieved through the design of an Internal Target Volume (ITV) as indicated in ICRU-62. However, the Dose-Volume Histogram (DVH) evaluation of the doses received by the healthy lung may vary in the case of designing a single lung volume, compared to the composite lung volume obtained with the fusion of normal breathing, inspiration and expiration (ITVlung ).