A patient is being treated on the 18-MV beam to a PA spine at a depth of 10 cm.The collimator setting is 10 x 13 with no blocks.The dose is 300 cGy per fraction.What is the dose delivered to Dmax?

Question

Quizplus · Accepted Answer

First find the equivalent square using Sterling's formula.A 10 x 13 equivalent square is 11.3.Look up the PDD on the 18-MV chart (Table 24-7)and interpolate to get a PDD of 80.03.

A Patient Is Being Treated on the 18-MV Beam to a PA