OBJECTIVES:
* Quantify the magnitude and distribution of inter- and intrafraction anatomic variations, including the temporal stability of the tumor/respiration signal correlation.
* Improve the acquisition and reconstruction of 4D CT scan images by advancing the 4D CT scan data collection process and evaluating 4D CT scan image reconstruction using different respiratory inputs.
* Quantify the uncertainty of deformable image-registration algorithms.
* Develop and investigate the efficacy of inter- and intrafraction probabilistic planning-based 4D image-guided adaptive radiotherapy (IGART) strategies for clinical application.
* Determine the expected geometric, dosimetric, and radiobiological improvements from the 4D IGART system.
OUTLINE: Patients undergo insertion of ≥ 1 small radio-opaque marker into (or in the vicinity of) the primary lesion or suspect lymph nodes via bronchoscopy. X-rays are performed to document the position of the markers.
Patients undergo 4D CT scan before each radiotherapy session and once a week after a radiotherapy session. Patients also undergo x-ray imaging before and during radiotherapy, optical and internal marker motion recording before and after radiotherapy, and audiovisual feedback during radiotherapy.
Patients undergo image-guided adapted radiotherapy based on these data.
