Radiation Leakage and Tungsten Alloy

The Valencia applicators which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands) are designed to treat skin lesions. These cup-shaped applicators are an alternative to superficial/orthovoltage x-ray treatment units.

They limit the irradiation to the required area using tungsten alloy shielding, and are equipped with a tungsten alloy flattering filter allowing the treatment of skin tumors, the oral cavity, vaginal cuff, etc. The tungsten alloy thickness to shield radiation is not the same in all parts of the applicators. This fact led us to question whether the leakage radiation differs depending on where it is measured, and whether this may be relevant in some clinical cases. The purpose of this work is to study from the radiation protection point of view the radiation leakage of the Valencia applicators, and provide a solution for current users and for the manufacturer.