The beam arrangement employed for the treatment of patients using eBt or superficial therapy is known as skin apposition; where the end of the applicator is angled so that it is parallel to the surface of the skin.

Contact should be established between the entire periphery of the applicator and the surface of the patient, therefore accurately establishing the required Focal Skin Distance (FSD).

Even small variations in distance between the end of the applicator and the patient’s skin will have an important effect on the dose delivered to the patient. 

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