Consequences of Anatomic Changes and Respiratory Motion on Radiation Dose Distributions in Conformal Radiotherapy for Locally Advanced Non-Small-Cell Lung Cancer

Serial four-dimensional computed tomography scans provided useful anatomic information and dosimetric changes during radiotherapy. Although the observed dosimetric variations were small, on average, the interfractional changes in tumor volume, mobility, and patient setup was sometimes associated with dramatic dosimetric consequences. Therefore, for locally advanced lung cancer patients, efforts to include image-guided treatment and to perform repeated imaging during the treatment course are recommended.