Basic Treatment Planning

Comparison of Pencil Beam and Collapsed Cone

Pencil Beam • 95% coverage appears greater

Collapsed Cone • 95% coverage is compromised in areas of the lung • Overall coverage is decreased. This can be most noticeable at the superior and inferior ends of the volume • Hotspots appear minimal • Calculates the effect of the inhomogenous areas in 3 dimensions

• Overall coverage is increased

• Hotspots appear in areas

affected by the lower density of the lung

• Calculates the effect of the inhomogenous areas in 1 dimension