An investigation into the effect of protective devices on the dose to radiosensitive organs in the head and neck.

A series of experiments were performed to determine the dose reduction afforded to radiosensitive organs in the head and neck by various protective devices. These included spectacles with plastic, standard glass, photochromic and lead-glass lenses, a thyroid collar and a lead-acrylic face mask. The measurements were performed using an anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosemeters, in conditions realistic of clinical practice. Irradiations were performed using scattered radiation produced by a pelvic phantom, for X-ray beams generated at 80 kVp and 110 KVp. It was found that the reduction in dose to the lens of the eye ranged between 0% and 97%, whilst the dose to the thyroid and oesophagus was reduced by between 76% and 97%, and was dependent on the protective device and tube potential employed. A reduction in brain dose of up to 81% was also measured, for the lead-acrylic face mask. Also presented is the ratio of organ dose to dose to the bridge of the nose for thyroid, oesophagus, brain and sinuses, as measured for the case of no head or neck protection.