Publication Date


Document Type


Committee Members

Matthew Daniels (Committee Member), Gary Farlow (Committee Member), Brent Foy (Advisor)

Degree Name

Master of Science (MS)


Intensity modulated radiation therapy (IMRT) plans can be further customized to each patient with the use of a four-dimensional (4D) respiratorygated computed tomography (CT), with time being the fourth dimension. The 4D respiratory-gated CT allows for the internal margin (IM), the expansion of the tumor volume that accounts for physiologic motions, to be addressed in the treatment planning process and no longer assumes that the treatments will be delivered to a fixed or rigid patient anatomy. Delivering the IMRT plan with a gated technique limits the treatment to a duty cycle when the target motion is at a minimum.

The goal of this project is to study respiratory-gated IMRT quality assurance (QA) results for tumor motion in two dimensions and develop a guideline for acceptable limits on tumor motion and field size. Respiratory-gated IMRT QA was performed for four field sizes and varying amounts of motion with a fixed duty cycle using Sun Nuclear's MapCHECK and MotionSIM XY/4D products. The treated and planned dose planes were compared and errors were evaluated using standard acceptance conditions.

Page Count


Department or Program

Department of Physics

Year Degree Awarded


Included in

Physics Commons