Brachytherapy device including an anti-static handle

Abstract

A brachytherapy device,for exposing to radioactivity a patient includes an elongate member such as a needle or cannula,adapted for introduction into the patient and also includes a stylet,slideably receivable in a longitudinal throughbore,in the needle,The device,also includes a portion,near either the proximal end,of the needle,or the distal end,of the stylet,which provides a local, defined amount of friction between the needle,and the stylet,The device,further includes an anti-static handle,connected to the needle,The handle,has an interior ramp surface,in communication with the throughbore,of the needle,frustoconical in shape and possessing an included apical angle of at least about 16°. The localized friction portion,can be a crimp or flange,on the stylet,or a crimp,or deformation,in or of the needle,The handle,is preferably composed of a polycarbonate, acrylic or acetal resin (such resins preferably being carbon-filled, or otherwise electro static dissipative), or a hydroscopic nylon blend. The device,is particularly advantageous in that the preferred ramp surface,in the handle,facilitates the insertion of seeds,of radioactive material and inert spacers,into the needle,The anti-static handle,eliminates, for practical purposes, the previously encountered risks of static interference, static cling of the spacers,and ignition spark generation. Finally, the localized friction portion,provides a controlled and predetermined amount of friction between the needle,and the stylet,preventing the stylet,from falling from the needle,while also preventing or reducing the risk of unintended ejection of the radioactive seeds,and spacers,Such friction is advantageously provided virtually the entire time any portion of the stylet,is received in the needle