Question: 13. A Patient’s Prescription Calls For A Prescribed Dose To A Point In The Patient At A Depth Of 10 Cm From The Skin Surface. This Is An SAD Treatment, Meaning That The Prescribed Dose Is To A Point At A Distance Of 100 Cm From The Linac Radiation Source. A Setup Error Is Made, And The Patient Is Actu- Ally Set Up At 95 SSD Instead Of 90 SSD. Will The …

13. A patient’s prescription calls for a prescribed dose to a point in the patient at a depth of 10 cm from the skin surface. This is an SAD treatment, meaning that the prescribed dose is to a point at a distance of 100 cm from the linac radiation source. A setup error is made, and the patient is actu- ally set up at 95 SSD instead of 90 SSD. Will the actual delivered dose be higher or lower, and by approximately how much? Give the answer as a percentage. 1