AbstractID: 6957 Title: A Surface Bolus Technique for Irregular Shaped Contours for High Energy
Photon and Electron Therapy
A Surface Bolus Technique for Irregular Shaped Contours for High Energy Photon and
Electron Therapy
Tissue equivalent bolus material is commonly used in radiotherapy. Treatment of the
breast, chestwall, head and neck are common treatment sites, which employ the use of
bolus. The bolus material increases dose to the skin and subcutaneous tissues, which may
be at risk, to a clinically desirable level.
A soft tissue-equivalent commercially available sheet material is commonly used for bolus
in radiotherapy departments. The material is effective provided the area of treatment is
regular in shape without varying topology. If the surface contour of the patient is
irregular, conventional bolus material may not conform well to the surface topology.
Applying conventional bolus to this site creates unacceptable air gaps between the bolus
and the skin. This may lead to a condition where a secondary buildup region exists on the
patient’s skin, which causes an under dosing of the area.
A bolussing technique has been developed which conforms to irregular surface contours.
The technique allows for simple fabrication, is cost effective, and rapid and accurate
placement at treatment time. The technique uses perforated aquaplast® and a nearly
tissue equivalent wax (Kindt-Collins, Cleveland, OH). When heated, the wax becomes
very pliable and readily conforms to the patient’s contour while preserving a desirable
thickness. When cooled the wax hardens and retains its molded shape. The finished
product resembles a cast of the patient’s surface. During treatment the bolus is quickly
placed on the patient and self-registers into position.