Brachytherapy apparatus and methods

Abstract

A brachytherapy apparatus is composed of a tubular needle with forwardly protruding cutting edges at its tip, a holder supporting the needle and a driver for electromechanically causing the needle to undergo a continuous or oscillatory rotary motion around its axis and/or a reciprocating linear motion in the longitudinal direction such that its front opening at its tip can reliably reach a specified position inside a patient's tissue without being deflected or bowing when it encounters an obstruction such as a calcification or a small bone. Such motions may be provided by a piezoelectric hammer and a piezoelectric tamper. After the needle is thus correctly positioned, a brachytherapy device such as a radioactive seed or a reflector may be pushed through and out of the needle by means of a pusher as the needle is retracted to leave a track inside the tissue. A quickly hardening liquid may be thereafter injected through the needle to immobilize the deposited brachytherapy device. Another brachytherapy device may be deposited similarly after the needle is retracted by a specified distance. A plurality of brachytherapy devices may be preliminarily prepared as a unit having them linearly arranged inside a hardened liquid and mutually separated by specified distances such that they can be pushed together through the needle, or they may be injected together with a quickly hardening liquid.