Respiratory Tumor and Normal Tissue Motion

Primary Objectives:

• To collect accurate and reliable respiration-induced anatomic structure motion data using four-dimensional (4-D) imaging technology.
• 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.
• To assess dosimetric and potential clinical consequences of respiratory motion in the current practice of radiotherapy through preclinical treatment simulation (treatment planning) studies.
• 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:

• 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.
• 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.
• To quantify the effects of radiation therapy on the patterns of respiratory-induced motion of structures through preclinical treatment simulation studies.
• To compare various strategies for either accounting for or mitigating respiration-induced motion in the planning and delivery of radiation therapy.