Study of elasto-gel pads used as surface bolus material in high energy photon and electron therapy.

Bolus materials are occasionally used during the high energy photon and electron radiation treatments of head, neck, breast, and chest wall areas in order to deliver the full prescribed dose to the skin surface and underlining tissue. Where skin surface curvatures make uniform contact between the bolus material and skin surface difficult, we have studied a new bolus material called Elasto-gel. Elasto-gel, packed in a sterilized envelope, is routinely used in the treatment of superficial burns and wounds. The adhesive nature of Elasto-gel bolus material provides excellent skin contact without air gaps. The Elasto-gel is made of non-toxic material and is transparent. High dose irradiation has no effect on the appearance and property of the Elasto-gel pad. We are presenting in this note the radiation attenuation and build up effects of the Elasto-gel pads of photon energies of 6 and 18 MV and of electron energies of 6 MeV and 20 MeV. There is little difference between Elasto-gel and Polystyrene in radiation dosimetry.