Applicators for brachytherapy treatment
An applicator for brachytherapy radiation avoids over-radiation in the distal axial direction from a source positioned in the applicator, by attenuating distal axial radiation which tends to over-radiate, causing a “hot spot” in tissue in the axial direction, when the radiation travels through air space in the lumen.
1 . A brachytherapy applicator configured to reduce or eliminate over-radiation in the distal axial direction, comprising:
an essentially solid applicator body, and at least one lumen inside the applicator body, of a size to receive a source of radiation inserted therein for brachytherapy radiation of tissue surrounding the applicator when placed into a patient's tissue, and
an attenuator generally at the distal end of the lumen, in line axially with the lumen, the attenuator having attenuating properties so as to reduce or eliminate over-radiation in the distal axial direction.
2 . The applicator of claim 1 , wherein the attenuator is positioned within a recess at the distal end of the applicator, the recess and the attenuator being larger in diameter than the lumen.
3 . The applicator of claim 2 , further including a closure element in the recess distal of the attenuator.
4 . The applicator of claim 3 , wherein the attenuator is a disc, and wherein the closure element comprises a plug distal of the disc, closing the recess.
5 . The applicator of claim 2 , wherein the attenuator is a plug closing the recess.
6 . The applicator of claim 1 , wherein the applicator body is formed of material having generally similar attenuation properties to living tissue within which the applicator is to be used.
7 . The applicator of claim 1 , wherein the attenuator includes barium sulfate.
8 . The applicator of claim 1 , wherein the attenuator comprises water or water solution within the lumen so as to fill the lumen distal of a radiation source when a radiation source is inserted.
9 . The applicator of claim 1 , wherein the attenuator comprises a liquid within the lumen so as to fill the lumen distal of a radiation source when a radiation source is inserted.
10 . The method of claim 9 , wherein the applicator has a proximal end hub with a filling port for admitting liquid into the lumen.
11 . A brachytherapy applicator configured to reduce or eliminate over-radiation in the distal axial direction, comprising:
a balloon applicator comprising an inflatable balloon secured to a shaft having an internal lumen, the internal lumen being sized to a receive a source of radiation inserted therein for brachytherapy radiation of tissue surrounding the balloon applicator when placed into a patient's tissue, and
a radiation attenuator generally at the distal end of the shaft's lumen and in line axially with the lumen, the attenuator having attenuating properties so as to reduce or eliminate over-radiation in the distal axial direction.
12 . The applicator of claim 11 , wherein the attenuator comprises a disc at the distal end of the shaft.
13 . The applicator of claim 10 , wherein the attenuator comprises a cap over the distal end of the shaft.
14 . The applicator of claim 11 , wherein the attenuator comprises a liquid within the lumen so as to be positioned distal of a radiation source when a radiation source is inserted.
15 . The applicator of claim 14 , wherein the applicator has a proximal end hub with a filling port for admitting liquid into the lumen.
16 . An applicator for brachytherapy radiation treatment of a living patient, with provision for reducing or eliminating over-radiation of tissue in the distal axial direction, comprising:
the applicator having a body forming an internal lumen within the applicator, the internal lumen being sized to receive a source of radiation inserted therein for brachytherapy radiation of tissue surrounding the applicator when placed into a patient's tissue,
the internal lumen being essentially linear such that, with the source of radiation emitting radiation from a series of different positions along the linear lumen, over-radiation ordinarily tends to occur in the distal axial direction, and
a radiation attenuating device generally at the distal end of the lumen and aligned with the lumen.
17 . The applicator of claim 16 , wherein the attenuating device comprises a disc positioned at the distal end of the lumen.
18 . The brachytherapy applicator of claim 16 , wherein the applicator is essentially solid and comprises said body forming the lumen, and the body including at a distal end a recess, with the attenuating device positioned in the recess.
19 . The brachytherapy applicator of claim 18 , wherein the recess and the attenuating device are larger in diameter than the lumen.
20 . The brachytherapy applicator of claim 16 , wherein the attenuating device comprises a liquid within the lumen so as to fill the lumen distal of a radiation source when a radiation source is inserted.