Purpose
The major uncertainties in treating lung cancer are the repositioning errors and respiratory lung tumor motion. Typically, margins are added to the clinical target volume (CTV) to obtain a planning target volume (PTV) allowing the accommodation of such uncertainties. We want to test a new technique to assess the adequacy of the chosen PTV using an aSi electronic portal imaging device (EPID).
Methods
Four patients affected by lung cancer and treated by radical 3D conformal radiotherapy (3DRT) were studied. During treatment the EPID was used in cine mode acquisition: acquired images were used to the aim.
Results and conclusions
Treatment monitoring with an EPID in cine mode is shown to be a clinically feasible and useful tool.