Primary Objectives:
1. To collect accurate and reliable respiration-induced anatomic structure motion data using four-dimensional (4-D) imaging technology.
2. To analyze these data to study respiration-induced variations and patterns in variations of positions, shapes and volumes of tumors and normal anatomic structures in the thorax and abdomen over a breathing cycle, from one breathing cycle to the next, day-to-day and over the course of radiotherapy.
3. To assess dosimetric and potential clinical consequences of respiratory motion in the current practice of radiotherapy through preclinical treatment simulation (treatment planning) studies.
4. To quantify the potential consequences of explicitly accounting for respiration-induced motion on dose distributions and outcome (tumor control probabilities and normal tissue complication probabilities) through preclinical treatment simulation studies.
Secondary Objectives:
1. To investigate the feasibility of using patient training to regulate patient breathing and improve the quality of images and to stratify patients for their eligibility for respiratory-correlated imaging and radiotherapy and for the implementation of various strategies for mitigation of respiratory-induced motion.
2. To assess the degree of correlation of the marker (or internal anatomic structure such as diaphragm) being tracked as surrogate of breathing with the motion of structures and the intra-fraction and inter-fraction reproducibility of such correlation.
3. To quantify the effects of radiation therapy on the patterns of respiratory-induced motion of structures through preclinical treatment simulation studies.
4. To compare various strategies for either accounting for or mitigating respiration-induced motion in the planning and delivery of radiation therapy. |