Factors involved in the development of a treatment plan are explained, including the determination of the volume to be treated, the dose to give, the fractionation schedule, and the field arrangement to use. Internal and external patient factors that influence a beam's distribution will be discussed. Dose volume histograms and dose distributions are analyzed to de- termine the need for beam modifiers. Isodose curves for pho- ton beams are compared. Students will also perform dose calculations. College-level reading, writing and math skills are required.