CA2192081C

CA2192081C - Flexible source wire for radiation treatment

Info

Publication number: CA2192081C
Application number: CA002192081A
Authority: CA
Inventors: Samuel F. Liprie
Original assignee: Interventional Therapies LLC
Current assignee: Interventional Therapies LLC
Priority date: 1994-06-08
Filing date: 1995-06-08
Publication date: 2001-11-20
Anticipated expiration: 2015-06-08
Also published as: AU695062B2; EP1374950A1; IL114013A; JP2916952B2; EP0765175A4; AU2942795A; JPH10506020A; IL114013A0; EP0765175A1; WO1995033512A1; DE69533423D1; DE69533423T2; US5503614A; EP0765175B1; CA2192081A1

Abstract

A flexible source wire (10) is provided containing a radioactive source (16) that is capable of maneuvering through a tortuous narrow passage to a treatment site within the body. The source wire (10) includes a thin flexible housing tube (12), housing therein a flexible backbone wire (14), both the tube and the wire being constructed from a material exhibiting little or no memory retention when bent. A radioactive source (36) is provided in the proximal end of a thin flexible housing tube (32). This radioactive source (36) is contained in a capsule (40) abutting the proximal end of the backbone wire (34) all within a thin wall encapsulating material (32). Both ends of the source wire (10) are welded shut to form a tight seal and rounded to allow ease of movement as it travels through the bends and turns in a body. The housing tube (12) is coated before the loading of the radioactive material with a non-oxidizing agent (40) such as gold.

Description

~ WO 95/3351~ 2 1 9 2 0 8 1 PC~/U595/1~6~16 ' ~ .
FI,~IBLE SOORCE WI~ POU R~DI~IIO~
T17 r.; ~

B~C~Gr~0~3 OF ~ ~IOh' 1. Fle~ o' the 7r-rertion The presert i-vert-cr relates to the use o_ racioactive sou=ces to treat c~seases of t:-e bocy- More pa=ticula=lv, the pres~et irr~erticr re_ates tc the use O,c a fl - ~ h7 - me~ber hcusins a rP~ rt;ve sou=ce f~r the tempcra~y de7ive~y Oc rad~at-or to treat ciseases o' the body.

2. Dess_iDticr o- the ~-io- A_t ~;ar:nn is usec to treat cance~ a c o.:"e- c-seases o. the body. Raciatior has lors been F=over to cest~ov Cas;
multiplvinc cel' 5 =(e.s., carce-~ in hcpes o- cest=cyi-g o=
prev~ntin the sc-ead o t-"e disease. ~=acky~"era_v-, wr-~" is the treatment of cancer at close distances, is ore examrle Oc the use o~ ra~izr; nn . or treatir~r diseases or ~the.bcdy. Du=ir.s brachytherapv, a rar:ozrt;ve sou_-e or sou=ces 2re rositiored in the area neecinS treatment. Depending~o" the shape, si-e and deliverv means Oc the r~rl;n~rt;ve sources, the sources are e-ther kept permanertly in the body or removed after a specific amou"t of time. Sirce pr_m~rlcr~ ;mp]~n~q are t~rv seeds aporoc-mately 3mm lons and .5mm wide, the use O,c these seeds do not relate to the present invertion. Corsequently, the ,Cocus O,c this applica-tion will be on the field of temporary implants.
The term temporary implants desc=ibes the procedure O,c maneuvering a radioactive source or sources to the treatment site ~r;l;7;ns a transport catheter or tube which has been prevlously placed ir the vicinity of this treatment site. Alternatively, the trarsport r~hotr-r and temporary implaat can simultaneou51y be maneuvered to the treatment site. In either s;r~ ;nn, a~cter a specified period O,c time, these sources and the trarlsport catheter or tube are removed ,Crom the bocdy. Since the radioac-tive source or sources may ercounter a tortuous path in various arteries, veins, ducts, or the like inside the body to reach the treatmer~t site, the r~;n~r~;ve source is usually attached by some device to a flecible drive member. This source and the drive me~ber m2y be used mar.y times, and, therefor must be able ~VO 95133512 2 1 9 2 0 8 ~ l~CTIUS95/06886 .
to withstarl~ the mary bercs it erc_urters wrer it is mareuvared to the t-eatmert 5ite o- rem.ov=c t:neref cm, withcu- brea.~-r.s.
Tkere a-e several cevice5 cr the mar.ket in wrich racioac_i-re SGU~Ces a_e attached to -~A'~7 Q c-ive mersers. Each of tkese ce-i-ces is c~rs.-ac~ec'. 1- a c'-f_ere"t rash cn anc each has ics lim~t2ticrs. ~c-mples Oe t'rese p-io. a - ce~,-'ces are c'escrisec iri ~ c Paterts ~,81~,618 a~ 5,1~1,486, 'sotr issued tc Lipr-'e as well as U.S. ~atert ~,80'1,520 Lssned tc var't --co~t.
Tke twc Lip~ie patercs desc=-be a r~;n~r~~ve elemer~ wh'-:a is attached to 2 dr_ve merLicer by mea s of a jurc.icr~ we~ced to the c~lve c 'cle. T~o patent to var't rOO~, desc-ihes a" apca=atus which ~ r~Qc rac'ioac.ive sources to a c~ive c~ble bv mears of - a st f_ cacs~le welced intc the erc o- the ca'cle. S~-ce t'-e mcst resistire po=ticr to flec~icr. o_ ~"ry fle~ ble mate-ial, such as a cable, tuhe, c= wire is the sesment closest to the e"c, ts join a capsule whi-h is ct-=So. th~" this material ~nc welded cr_o its end would orl7y acd to the resist~r!ce to hernd _- ~nc wculd adverselv ofrPrt m*no1lverirs the material t -ousn t_e boc-r.
~ S. Patent 5,081,002 issued to Liprie cesc=ibes ar ultra-thin hish dose iridium source ;rr~n~Q~ within an ove-sized hole drillec. ir~ide the end of a solid platir~um wi-e. ~he whole assemsly is then drawn down to the desired diamete- of the wire Nhile this patent does rot describe the situatior in which a r~;oant;ve source is ~oined to the end of a solid cable, the platinum delivery wire would still present problems with respect to mar.euveri~s the wire throuch the rumeral twists and tu-cs in the body.
Finally, ~.S. Patent 5,28~,781 issued to Liprie employs a tube, a h~rkhrno wire, a pure iridium core ard a plug ard draws down the entire assembly to form a tight seal between the housing material ar~d the backbone wire and the plug. Without this drawinr down o~ the housing onto the har~nno wire, radioactive flakes from the core would migrate throughout the irside of the assembly wire, resulting in unwanted ~nnt~m;n~tinr This "drawirc dowr'~ step would increase the costs ~nd difficulty of manufacturins the source wire.

' . WO 95/33512 i~ ~ 9 ~ ~ 8 1 PCI'IUS95106886 S~V' OF T~: ~V~TIO~
These ard othe- r~;ri~r;~q o~ t~e p--o= a=. a_e ac~ressed bv the presert invertion which is ci_ectec t_ a flexible scu=ce wire for the ~r;~t;n~ t-eatmert c c sease in 5 w~ich the scu-ce wire cc-tains a radicac_i~e s_urce a-c is ~ -L-d to the site o_ e=eatmert tk-oush va~ious c_rc--ts in the bccy. The fle~ble scu-~e wire ;~ rQq a fl~-ihl~ housirs in the form of an elorsatec kollow tube const--c~ed __om a mater-al suc~ as ~itinol~ cr a t-tan_um~rickel allov w~ch exhibits little or no memc-y r-~ ;nn when it is ber~
internal fle ~ble b~r~nnP wire also const-~ctec -=c~ the same material as tke fla-~:hl~ tube wkich P-~:hi~q lit;le or ro memc-y retenticr. The back~cre w-=e is prov-ded w-thin he fl~-~ h~
tube.
A t~in-walled capsule or encapsulatec r~ o~rt;ve core as well as a plug is also pr~vided within t_e _lexible tube. Tke backbone wire is welded to the distal end of the tube arc r~nS
throushout the length o_ the flexible tube to a c-star.ce just short of the oroximal end of the tube. The r~:n~r~;ve capsule or encapsulated radioactive core which is provided in the proximel portion of the flPY;hlo tube, abuts the end of the backbone wire. The encaosu~ating material must have a ve~y th~
wall to allow flex~bility. This thin wall should be corstructed from r~t~r;~l that will block ver,v little of the neutron flu~ as the core is being irradiated, as well as not bPrnm;ng radioactive or exhibit an insisnificar.t amount of r~;oartivity a=ter a period of approximately 20 days. A good example of this material is titanium, rl ~t;nllm, gold or high purity aluminum such as aluminum 1100.
A plug is provided at the proximal end o' the tube to seal the radioactive capsule or the encapsulated radioactive core withir, the tube. Mour.tirg the r~ioartive source into the segment of a tube which is naturally stiff would not add any appreciable resistance to bending, in c~ntradistinction to the Liprie '618 and Liprie '487 patents, as well as the patert to van't ~ooft. Since material such as Nitinol~ as well as a t;t~ninm/nickel alloy which exhibits little o_ no memory /
.

_ _ _ WO 95~33512 ~ 9 ~ 3 ~ ~ PCI~/US95/06886 retent on when ke~t ha-;e d-'ssimila~ weidl~~ D-oDe-t'es thar cthe-metals, ehey do rot 'o-m a s;rors borc'. a5ains. the stress Oc repeatec ker.d'n5. This 'eature woulc reduce the poss-bility that the de-;ice is p-ore to bre~kase.
Fu=the~more, c'ue to the ch~-acte-istics c- "little o-no me~c y" material suc'~ as ~i-irol~, a t-t~niLm~.-'ccel allrv, etc , t~e "d-awln5 dowr~ os the mate~ial illust-ated i- Lio-ie '781 is rot possikle. Eu-the~ore, provid nS a scu_ce wi~e as illus.-ated i Llorie ~Q02 i which ~un i_ic-um sour_e is ir.se-ted into a kole wkich is d=-lled into the erd Oc a th w--e is not necessa~f. Drillin5 a hole into a th~r wi e i5 ve-y *~S,~~r~
sirce the m~~imum depth the hole caun be c'_illec is equal to approx-~ately sever times the cutside diame~e- Oc t~e wire. To d_ill a hole deeper thau- this dis.ance is exoremely ci_ficul; due to the ~~;ft;"s Oc the drill as its bu- ows the hole. This driftin5 car leac to a th;nn;n5 o~ ths cav~ -y walls wrich ç eatly increases the charces or breakage. This breakare is often disastrous, resultirg in unwarranted r~*;~tinn etposure. A
larger outside diameter wire will be needed to rn~?Pnc~te for the drifting and still allow the walls o_ the cavity to be thick enough to withstand stress. ~n_ortunately, this la-ger diamete wire misht be too large t,o _it into mary constricted areas o_ the body. Additionally, this larger diameter wire woLld result in less ~Clexibility and may not be a'ole to be manew-ered to the treatment site. Another method of drillin5 the cavity inside a solid wire, would be to start with an oversize wire and an oversize hole znd draw the entire structure do~n to size.
Whenever a wire is drawn down, the assembly rnnt~;n;nr the cavity r-lnng~t~c and precise positioning o~ the r~;n~rt;ve core insioe the assembly can become very di_~icult ~t;1;7;ng a tube as the flexible source as is rt;~ in the present invention would ~ ;n~ ~ the need for this type of ~r;~;ng ~ . ~VO 9~133512 ~ ~ q 2 3 8 ~ P.~ ;C~

~RI~P DESC~I~I~N CF ~E~ DRA~INGS
Tkese and other zttributes o the present inv~"tion will be described with respect to the ~ollowin5 drawirgs in which:

FIG. 1 ~s a partial c-oss-sectlon or the in~ention showing a r~ ntive core inside a thin.wall capsule provided within the ~7~i hl ~ source tube;

FTG. 2 is a pa-tial croSS-SeCtiQn o~ the prese"t Invention showing the use Oc the encapsulated core within the fl ~;hl ~ source tube; and FIG. 3 is a partial cross-section of the present invention provided with a proximal end haviug a ~ el shape , W095/33'12 21 9~8 1 PC:r/Usg.S/a6886 . I~i ';"~rI,~" " S~RI-~TIO~ OF TE~ rN~ TION
FI~. 1 illust=ates a rirst cm~cr';mo"~ c- the present inVen~'OIl lQ nril i7;"c a radioactive CQ-E 16 p=o-v-iced withi:l a thir-wallecd capsule. T is o~hor';mcr~ employs ~" elc.satec' h~o'70w s hous~~s tube 12 corst~ictec' frsm a mate~ al such as Nit-rcl~', a titan'~m/nickel alloy o= simila~ mate~ials w;~ ch e-~klbit littla or no memory retertior.-wrer tre tube is beut. Since this housins tube _s usec to mare~ ver the r,r';n.7c-;~e cora to a remose treatment site, the le-cth o~ tke ture is gpno~ ; Srea~e- than lOOcm a-d, could o~tenc 'sr a muc~ greOate~ d'st~nce. Accitioral-ly, s'-ca the housir,5 tube must be ma."eu~erec' w-thin various twists ard t~15 ir the bcdy throus:n va-ious corcnits there -, - the c'-':meter o, this t-_ e could r2r~se f-om 0.013" to 0.023".
A Cla~ble bac.~ore wire 14 is pro-~-dec betweer tka dista' enr' 1' o~ housi-s tube 12 ~nc exterds to several millime~
ters f-cm the end of the prcximal portion '3 oC the hous-ns tube.
.?or e~~se of ;n;t;.7l1v irser,ins the bac~hore wire 14 into the tube ' 2 and to allow s-eater pivotins Oc the assembly wkila reduc-'-g stress to the housins material, the end 24 of this wire ZO is ro~nded. Similar to the housing tube 12, this back!one wi-e 14 ca- also be const_..cted from material such as Nitinol~', a tit r:nm/nic.'~el alloy o- other materials wkich e-~hibit little or r,o memory retention wher bent.
A capsule 20 is inserted into the proximal end of the housins tube 12 until it abuts the rounded erd 24 of the backbore wire 14. The capsule should be manufactured f=om a very thir.-walled metallic material. The r;7~i;n~7rt;ve core 16 is than irserted within the capsule and a plug 22 abuttir.g the proximal end o, the core 16 is provided within the capsule 20 and is used to seal the r~r';o;~ct;ve core 16 in place.
The plug 22 is sealed in place using a weld 25 or other methocs of ~orming a tisht seal. The distal end of the backbone wire 18 is welded in place at 26. }30th ends 21, 23 O,c the housi..s tube 12 are rounded to allow ease Oc movement as it travels throush bends and turns in the body. The exterior of the housins tube 12 is coated prior to the loading of the radioactive core 16 with a non~oxidizing agent, such as gold. The backbone .. ~

~ WO95133512 ~ ~ pCT~595l06886 wire 14 car be weldec, Cused or sluec. to c'~'e_ent a-eas o- tke inne~ tu'oe, Snch zs 27 to se~re as ~" ~nS=-n,- sa e,y anc protec~ion device. Ic the oute~ tube 12 b~eaks, the rac oactive sou~ce 16 wou~a still be ~ble to be res=acted. Fc- ease of ;nse-~-'rs t'e h~r~nno wi-e 74 into the ;~r-- nr c- the tube 12, a sma'l cap 2a betwe=n the irne~ s.~rrace o- the s~ne a-d -~he outer Sn-C~rr- o' the wi~e is p-ov~ded. The outsic'e d ~ete~ o~
the ca~sule 20 should ~it srus'y against t-e insice c-'~~ete= of the tune 12. Eoweve-, it is roted that a small Sap c~- also be ;rr~ S hetwer-n the capsn~e 20 ~-c. tke in~e-ior ~a 1 c- the t~e F~r- 2 il'ustrates a secorr' emood-men- 30 o- the prese_, ir~ventior utiliz-ns ~ elorsated cvl:scrica: hous'-r tube 32 simila~ in dimcrsior to the tube desc~'bed wit'- res-ec- to lS FIC-. l. This tuhe is corst-ucted f-om mate~ial SUG- as Nit--ol~, tit~nium/rickel alloy or a simil~- maeerial w ~ cr eY--b-,s l-ttle or ro memo~f reter~tion.whon be t A b-rkhn~ wi-e 34 c-rst-,~cted ~rom the same material as the housi~g tuhe 32 is i=trocuced to the itterior o~ the housirg tuhe 32 ard eYtends ~r_m the dist~l erd 31 thereo~ to ar area pos;t;nnr-~ several m-'llimeaers ~-om the proYimal erd 33 of the tube. The h~rk~nro wire 34 is provided with rounded ~ad 42 to aid ir movemert withir the tube 32. A
source o~ r~-l;n~rt;vity 'i6 is provided withir a tk~n wall onr~n5n1~t;r5 m~torj~- so so that it abuts the rourded erd 62 of the har~hnnr- wire 34 This thin ~-tor;~l 40 should allow the passage of neutrors to irradiate the inner core but the same time this material should obtain no signi~ica~t r~;n~r;vity. The r~;n~t;ve treatmert to be delivere~ must come Crom the r~ t;nn ~o~ a~ the inner core 36 a~d not ~rom the r~ t;nn exposure of the encapsulation material 40. The pnn~nS~ t;nn material should be fl~;h~C ~ good eYample of this material would be ~l~t;ml~, gold, titanium, or hish purity n1-m such as ~lnm;nllm 1100.
The backhone wire 34 is introduced into tke distal end of the housing tube 32 and is welded in place by weld 44.
Additionally, the ba~kh~no wire 34 car be a,~ixed to various inner sur~aces of the housing tube 32 such as at spot 4a by WO 95/3351Z . 21 9 . ~ 8 1 PCTJU59!;~'06~6 weldins, fusins, pasti-,s or othe= met~ccs A smal1 gap 45 is provide~ betweer. the cu;er sur_ace Q~ :the h~rl~nr~ w ~e 3~ ~n.&
the isner s~ aco o_ the hcus nc tuQe 32- Tk s San a cs i~
allcw s the bac.cscne wi=e 3c tc be mcved to its p~ope= cos--ior w'th_ the hous-..s tu'ce 32. The ercacsulated core is irt--cuced irto the into~;r~ nf the haus -c tu~e ;2 at i~s p~cxi,mla1 e.d so that it abuts the rol~n~en ecce _2 Oc the bac'~ore wire 34 A
plug 43 ls ther loaded ir~to the p-~ximal er~ o~ the housir.s tube 32 6c that it abuts the rounded p_c.-c~mal end 55 O~c the encapsu-lated core ~ke plug is the_ weldec i~ place by we'd 5c ~o~hthe prcximal ~r.c& distzl en&s o_ the hous -s tube 32 ~ e ro~-ded at 50, 52 to aid ir~ the m~neu-;o ~h 1i,v cf the housirs tube 32 w~th-r. the body Fur'he more, simila- to the embcc mer.t illustrated in FIG. 1, the oute= s -face Oc the hOus-mls t ce 32 is coatec with a nor-n-r-n:-~ns acent such as sold FIG 3 illustrates a fle-c~ble source wire similar ir.
many respects to the Pmho~;r--ts shown in E}C-S. 1 ~nd 2. I- this Pmho~i t~ similar ol omonrC in FIC- 1 will have the same reieronce numerals as their respective ol orcntC in FIC- 3 Purthenmore, although the embodiment shown in FIG 3 illustrates a flexible source wire nt;l;7;n~ 2 radioactive core within a - capsule, these tQ~nh;n~c c~n ~lso be applied to the ~it-~tinn in which the r~;o~nt;re core is encapsulated.
After the bac.~bone wire 14 is inserted throush the distal end of the housing tube 12 ~nd properly a~fixed in place, the capsule 20 is intrQduced ir~to the proximal end of the housing tube 12 by ut;l;7;ng a stylet The inner portion of the wall of the housins tube 12 o~h;hj tc a slightly tapered furnel shape 60 or is countersur~k at the proximal end O~c the tube to aid in the introduction of the capsule. Similarly, the encapsulated r~in~nt;ve core shown in FIG 2 can re introduced into a tube having a slight funnel shape at its proximal end. Orce the capsule is i~ place, the r~;nant;ve core 16 is ir~troduced therein manually ut;l;7;n~ a tweezers or ~tnm-t;cally employing a si,m.ilar device in a rohot handling system Once the capsule 20 and the r~;na~t;ve core 16 or the encapsulated core 36 is introduced into the proximal end O~c its respective tube until it ' ' WOgSr33si2 2 920~ 1 PCrlUS9~lOfi88~

abuts ~ne proximal end o~ its respective b~rkhnn~ wire, a plug is 102~ed in place a~d then sealed.
~ avln5 desc-~hed several embodlments of tlTe new ard im~roved T~ ;hl~ source wire ~or r~~;~T-;nn t_eatment in ~ccnr~T~nr~ with the present inve~tion, it is ~elieved that othe-~ ';fi~t'nrc, variatio~s and changes will ~e suggested to those skilled in the art in v_ew o~ the descri~tion set ~or~h above.
It is there~or to be ~Tn~rqtnod ~ha~ all suc varlations, m~';f~c~~;nnq and changes are believed to fall wlthln the scope o~ the invention as defined i~ the appen~ed cla_ms.

Claims

WHAT IS CLAIMED IS:

1. A flexible source wire for radiation treatment of diseased within a body comprising:
a flexible, hollow, elongated housing tube having an outer surface, an interior wall surface, a distal end, and a proximal end, said proximal end having an inner surface, said housing tube constructed from a material exhibiting little or no memory retention allowing said elongated housing tube to return to its original shape after it was bent;
a flexible backbone wire having a proximal end, said flexible backbone wire provided within said housing tube and constructed from material exhibiting little or no memory retention allowing said backbone wire to return to its original shape after it is bent.
a sealing device; and a radiation device provided within said housing tube, said radiation device include within said sealing device.

2. The flexible source wire in accordance with claim 1 further including a plug which is sealed to said proximal end of said housing tube.

3. The flexible source wire in accordance with claim 1 wherein said sealing device is a capsule having a distal end which is inserted into said housing tube prior to said radiation device being inserted into said housing tube.

4. The flexible source wire in accordance with claim 1 wherein said sealing device is a thin-walled material which completely encapsulates said radiation device prior to inserting said radiation device into said housing tube, said sealing device having a proximal end and a distal end.

5. The flexible source wire in accordance with claim 1 wherein said housing tube is constructed from an alloy comprising approximately 50% titanium and approximately 50%
nickel.

6. The flexible source wire in accordance with claim 3 wherein said housing tube is constructed from an alloy comprising approximately 50% titanium and approximately 50%
nickel.

7. The flexible source wire in accordance with claim 4 wherein said housing tube is constructed from an alloy comprising approximately 50% titanium and approximately 50%
nickel.

8. The flexible source wire in accordance with claim 1 wherein a port-on of said inner surface of said proximal end of said housing tube exhibits a tapered funnel shape for ease of loading said radiation device within said flexible housing tube.

9. The flexible source wire in accordance with claim 4 wherein said sealing device is constructed from titanium, platinum, or high purity aluminum.

10. The flexible source wire in accordance with claim 1 wherein said outer surface of said housing tube is coated with a non-oxidizing agent.

11. The flexible source wire in accordance with claim 10, wherein said non-oxidizing agent is gold.

12 . A flexible source wire for the radiation treatment of diseases within a body comprising:
a flexible, hollow, elongated housing tube having an outer surface, an inner wall surface, a distal end, and a proximal end, said proximal end having an inner surface;
a backbone wire having a proximal end, provided within said housing tube;

a capsule inserted into said proximal end of said flexible elongated housing tube, said capsule provided with a distal end;
a radioactive device inserted into said capsule; and a plug which seals said proximal end of said housing tube.

13. The flexible source wire in accordance with claim 12 wherein said housing tube is constructed from an alloy comprising approximately 50% titanium and approximately 50%
nickel.

14. The flexible source wire in accordance with claim 12 wherein a portion of the inner surface of said proximal end of said housing tube exhibits a tapered funnel shape for ease or loading said radiation device within said flexible housing tube.

15. The flexible source wire in accordance with claim 12 wherein said outer surface of said housing tube is coated with a non-oxidizing agent.

16. The flexible source wire in accordance with claim 15 wherein said non-oxidizing agent is gold.

17. A flexible source wire for radiation treatment of diseases within a body comprising:
a flexible, hollow, elongated housing tube having an outer surface, an interior wall surface, a distal end, and a proximal end, said proximal end having an inner surface;
a backbone wire inserted into said elongated flexible housing tube;
a radiation device which is encapsulated to provide a sealed source of radiation, said sealed source of radiation provided with a distal end; and a plug which seals said proximal end of said housing tube.

18. The flexible source wire in accordance with claim 17 wherein said housing tube us constructed from an alloy comprising approximately 50% titanium and approximately 50%
nickel.

19. The flexible source wire in accordance with claim 17 wherein a portion of said inner surface of said proximal end of said housing tube exhibits a tapered funnel shape for ease of loading said radiation device within said flexible housing tube.

20. The flexible source wire in accordance with claim 17 wherein said outer surface of said housing tube is coated with a non-oxidizing agent.

21. The flexible source wire in accordance with claim 20 wherein said non-oxidizing agent is gold.

22. The flexible source wire in accordance with claim 3 further including a means for reducing stress and for allowing greater pivoting of the flexible source wire at said proximal end of said flexible backbone wire and said distal end of said capsule.

23. The flexible source wire in accordance with claim 22 wherein said means for reducing stress and for allowing greater pivoting includes a rounded end of said backbone wire and a rounded end of said capsule adjacent to said rounded end of said backbone wire.

24. The flexible source wire in accordance with claim 4 further including a means for reducing stress and allowing greater pivoting of the flexible source wire at said proximal end of said backbone wire and said distal end of said radiation device.

25. The flexible source wire in accordance with claim 25 wherein said means for reducing stress and allowing greater pivoting includes a rounded end of said backbone wire and a rounded end of said encapsulated radiation device in proximity to said rounded end of said backbone wire.

26. The flexible source wire in accordance with claim 1 further includes a means forming a backup safety and protection device to ensure that said backbone wire remains in place within said housing tube.

27. The flexible source wire in accordance with claim 26 wherein said means forming a backup safety and protection device includes affixing said backbone wire to said interior wall surface of said flexible housing tube at one or more locations.

28. The flexible source wire in accordance with claim 12 further including a means for reducing stress and allowing greater pivoting of the flexible source wire at said proximal end of said flexible backbone wire and said distal end of said capsule.

29. The flexible source wire in accordance with claim 12 wherein said means for reducing stress and allowing greater pivoting includes a rounded end of said backbone wire and a rounded end of said capsule adjacent to said rounded end of said backbone wire.

30. The flexible source wire in accordance with claim 12 further including a means forming a backup safety and protection device to ensure that said backbone wire remain in place within said housing tube.

31. The flexible source wire in accordance with claim 12 wherein said means forming a backup safety and protection means includes affixing said backbone wire to said interior wall surface of said flexible housing tube at one or more locations.

32. The flexible source wire in accordance with claim 17 further including a means for reducing stress and allowing greater pivoting of the flexible source wire said proximal end of said flexible backbone wire and said distal end of said sealed source of radiation.

33. The flexible source wire in accordance with claim 17 wherein said means for reducing stress and allowing greater pivoting includes a rounded end of said backbone wire and a rounded end of said sealed source adjacent to said rounded end of said backbone wire.

34. The flexible source wire in accordance with claim 17 further including a means forming a backup safety and protection device to ensure that said backbone wire remains in place within said housing tube.

35. The flexible source wire in accordance with claim 17 wherein said means forming a backup safety and protection device includes affixing said backbone wire to said interior wall surface of said flexible housing tube at one or more locations.

36. The flexible source wire in accordance with claim 1 wherein said flexible backbone wire is affixed to the interior wall of said flexible housing tube at one or more locations to prevent migration of said radiation device throughout the flexible source wire.

37. The flexible source wire in accordance with claim 12 wherein said flexible backbone wire is affixed to the interior wall of said flexible housing tube at one or more locations to prevent migration of said radiation device throughout the flexible source wire.

38. The flexible source wire in accordance with claim 17 wherein said flexible backbone wire is affixed to the interior wall of said flexible housing tube at one or more locations to prevent migration of said radiation device throughout the flexible source wire.