Surface Dose Accuracy In Vmat Head And Neck Radiation Treatment Using Bolus

The accuracy of Eclipse (TM)-calculated head and neck VMAT plan dose delivery was assessed in the situation when there is a gap between placed bolus on a head and neck thermoplastic mask and the body surface. GafchromicEBT3 film dosimetry was used for dose delivery validation. The results from 3%, 3 mm 2D gamma comparison indicate better than 95% agreement between measured film dose and calculated plan dose for gap widths up to 25 mm between placed bolus and body surface.