Row of radioactive seeds and non-radioactive spacers and connector therefore

#This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/NL01/00647 which has an International filing date of Sept. 3, 2001, which designated the United States of America.

#The invention relates to a row of radioactive seeds and non-radioactive spacers arranged with a predetermined pitch, in which the number of spacers can be zero, for a brachytherapeutic treatment of an animal body with radioactive radiation, which seeds have elongated shapes.

#Such a row is known from Dutch patent application 1012697 and American patent application Ser. No. 09/377,382.

#The invention will now further be described with reference to the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and in which:

#FIG. 1 shows, on an enlarged scale, a seed/spacer;

#FIG. 2 shows a connector with introversions at both ends;

#Referring to FIG. 1 reference number 1 indicates the general shape of seeds. The seed has an elongated shape in which dimension L in longitudinal direction is of the order of 4,5 mm and in which the diameter D is of the order of 1 mm or smaller. In one embodiment of the invention the spacers are of the same dimensions as the seeds shown in FIG. 1. In another embodiment of the invention the spacers are shaped as shown in FIG. 3 to be discussed later on. In order to arrange seeds and spacers of the shapes and dimensions as shown in FIG. 1 into a row, such as described in the introduction, with a predetermined pitch, which row is physically coherent, connectors can be used such as shown in FIG. 2 with reference number 2. Connector 2 has been manufactured of bio-absorbable material, which in this field is an known group of materials. Element 2 has an elongated shape and is provided at both ends 3 and 4, respectively with introversions 5 and 6, respectively. Also element 2 of the embodiment shown in FIG. 2 has been provided all along its length with a slit 7. Element 2 is also provided with a connecting opening 8 between the introversions 5 and 6 and the slit 7 extends from the outside of the connector 2 to the introversions 5 and 6 and the connecting space 8 between said introversions. It is noted that the existence of the connecting space is optional as well as the slit 7 being continuous. Other embodiments of a connector 2 with introversions 5 and 6 at both ends 3 and 4 are made up by connecting space 8 not being present and/or by slit 7 not being continuous from end 3 to end 4. In the latter case the connector 2 comprises two slits at the location of the slit parts 7A and 7B of slit 7, which two slits are not connected together. The two slits mentioned in each case run from the outside of connector 2 to the introversions 5 and 6, respectively. Another embodiment of a connector 2 such as shown in FIG. 2 is made up by a connector in which no slit 7 is present at all.

#In case connector 2 is provided with a continuous slit 7 or with two non-continuous slits at the location of the slit parts 7A and 7B the introversions 5 and 6 are somewhat flexible as a result of the presence of the slit and slits, respectively. In that case the diameter of the introversions 5 and 6 is fractionally smaller than the diameter D of a seed or a spacer. As a consequence, there is advantageously a slight degree of clamping which is favourable for the physical coherence of the row of radioactive seeds and non-radioactive spacers arranged with connectors 2. In the case of neither a continuous slit 7 nor two separate slits at the location of the slit parts 7A and 7B the shapes of the introversions 5 and 6 are not flexible. In that case the inner diameters of the introversions 5 and 6 should be fractionally larger than the diameter D of the radioactive seeds and non-radioactive spacers respectively, such as shown in FIG. 1 and/or in FIG. 3.

#The choice to apply a slit 7 or two slits at the locations of the slit parts 7A and 7B is amongst others dependent upon the flexibility of the bio-absorbable material from which connector 2 has been manufactured. The stiffer the relevant material, the more need for slits 7.