A Patient Is Treated Using Two Superiorly/inferiorly Adjacent Fields

question 27

Multiple Choice

A patient is treated using two superiorly/inferiorly adjacent fields.The collimator setting for the superior field is 10 cm wide by 13 cm long.The collimator setting for the inferior field is 20 cm wide by 35 cm long.Both fields are treated at 100 cm SSD.Calculate the gap at the skin surface if the fields abut at a depth of 5 cm.

• A) 1.5
• B) 1.2
• C) 2.0
• D) 1.0