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1163D Virtual planning study m the management of brachytherapy Cesium132 Indium192 Palladium103 implants
$29
113
114
Development of a navigation system for needle application in interstitial brachytherapy
Ineer-inltltutional i u r v o y on procedures for n r & c h ~ h e z a p ¥ Neeherl~nds
G. Stral~mann, C. Kolotas, R. Heyd, T. Martin, H. Vogt, N. Zamboglou Sttldt. Kliniken Offenbach, Slrahlentherapie
IKK K o l k m a n - D e u r l o o , A Riinders. AHL Aalbers, Dries, MA Moerland, B Schaeken, JLM V e n s e l a a r The N e t h e r l a n d s / B e l g i u m
Introduction: The quality of interstitial brachytherapy depends on the precision of needle placing. The task for a qualified needle application depends on the tumor geometry. The aim was to construct a CT-supportet navigation system, based on electro-magnetism measurement, which allows exact needle placing and its reconstruction. Material and Methods: With the help of a 3-D-digitizer the coordinates( as for instance the top of needle) are measured in space and projected in the prepared CT-siices. In the CT-slices, the prospectiv stitch canal of the needles can be simulated.The software, which is needed for this, was programmed in WINDOWS-NT with VISUAL C++. This makes it possible to be furthermore in direct network connection with the planing system. After needle application the needle reconstruction is possible with the same system. The needle geometry get afterwards transfered directly to the planing system. Results and discussion: In our experiment the accuracy of the needle application was measured between 2-4mm +/0,75mm, the accuracy of needle reconstruction between 24,5mm +/- 0,75ram. In spite of the electromagnetic function of our system, the disturbig influence of the metal needles can be neglected. During intraoperative applications the system can be handled by speech recognition. Conclusion: Our navigation system allows an exact "free hand"-application by means of preceding CT-diagnostics in the interstitial brachvtherapy.
Quality Control (QC) ~n B o l ~ i u m skid The
Introduction: T h e N e t h e r l a n d s C o m m i s s i o n on Radiation D o s i m e t r y (NCS) has p u b l i s h e d reports on dosim e c r y and QC p r o c e d u r e s of r a d i o a c t i v e sources used in b r a c h y t h e r a p y (BT) a n d c a l i b r a t i o n of Ir-192 HDR sources (reports 4 and 7). A n e w task group of the NCS, in c o o p e r a t i o n w i t h the B e l g i a n A s s o c i a t i o n of Hospital P h y s i c i s t s (BVZF/SBPH), has i n i t i a t e d the d e v e l o p m e n t and i m p l e m e n t a t i o n of g u i d e l i n e s for QC of b r a c h y t h e r a p y equipment in The N e t h e r l a n d s and Belgium. Material and methods: In a first phase it was dec i d e d to e v a l u a t e the c u r r e n t p r a c t i c e regarding QC p r o c e d u r e s for BT by m a i l i n g a q u e s t i o n n a i r e to all institutes performing BT in B e l g i u m (21) and The N e t h e r l a n d s (19). In a d d i t i o n to an i n v e n t o r y of BT e q u i p m e n t and BT p r o c e d u r e s p e r f o r m e d in 1996, it addressed the current QC procedures regarding safety systems, afterloaders, localization equipment and source c a l i b r a t i o n . Results: The s u r v e y d e m o n s t r a t e s a high incidence of HDR and PDR afterloaders, with the frequency of QC p r o c e d u r e s dominated by the f r e q u e n c y of the s o u r c e exchange. The most f r e q u e n t l y used m e t h o d of implant reconstruction makes use of a simulator, w i t h a few z n s t i t u t e s r e p o r t i n g the use of CT for target d e l i n e a t i o n . The QC of the r e c o n s t r u c t i o n procedure is u s u a l l y limited to the regular mechanical checks of the simulator with specific tests ( r e c o n s t r u c t i o n of a k~own implant geometry) only d u r i n g acceptance testing, e.g. of new releases of the t r e a t m e n t p l a n n i n g system. A more extensive a n a l y s i s of the results of this s u r v e y with special r e f e r e n c e to QC frequencies and tolerances will he discussed. Discussion: In a next step this s u r v e y will be completed by an i n t e r c o m p a r i s o n of the c o m p l e t e BT p r o c e d u r e using d e d i c a t e d phantoms and on site visits to e v a l u a t e the overall p r e c i s i o n in dose delivery with the d i f f e r e n t BT systems used in BelaJum and The Netherlands.
115
116
Accuracy of source strength measurements for Irldium-192.
3 D \,'irtual plannine stud', m the manao_emcnt of hrachytherap3 C e s i u m " - I n d i u m 1~: Palladium ' ~ i m p l a n t s
C
Fellner. R Potter AKH Vienna. Umversity Department for Radiotherapy and Radlobiology, Vienna. AUSTRIA
Burette R. ( M D ) . V a n D y c k e M. (Ph.vs) C 1 S t Jean - Radiotherapy & Brachytherapy Department- 114 rue du Marais - 1000 B R U S S E L S D C - B e l g i u m -
Introduction: The basis ofevery treatment of a patient as the knmdedge of the source strength in terms of the air kerma rate In the certificate of the manufacturer the air kerma for Indium-192 sources is specified with an inaccurac.', of ±10% The ann of this stud.'. ".','as to exanune these '~alues and to compare measurements of the air kerma ,.,.lth iomsanon cbambers in air. ~.aler and perspex Material and method: For our ~.vo HDR and tw'o PDR aflerloadmg machines from Nucletron v.e use sources manufactured b?. Malhnckrodt Between September 1993 and December 1997 v.e performed for 30 HDR and 22 PDR sources dosimemc measurements v..ith 13.9e 2571 iomsatlnn charters from P'I"3,V The measurements ,.,.ere done wdh an 'in-air" phantom. V.lth a small water phantom or vdth a phantom made out of perspex. For the 30 HDR sources 83 measurement series and for the 22 PDR sources 82 senes were performed m air For 7 HDR and 5
Since 97. for patients ~ith early breasts cancers It '~: brachytherapy boost, H & N . prostate, gynecological and anorectal tumors, we developped T P S m e t h o d o l o g 3 (Plato °) on a pre-treatment virtual simulation. Paris S3stcm rules were followed and dose v o l u m e delive R" studied & c h e c k e d for rcproducibdily.
PDR sourcescompasat*vemeasurements~re performed m au and m water For 4 HDR and 4 PDR sourcescomparativemcasurcmentst~crc performed in air and in perspex Results: The mean deviation between the kerma specified in the cemficale and the measured kerma in air for the 30 HDR sources was u,6±2.5% ( I o) and for 22 PDR sources -4,4+_3,3% The comparative measurements in air and in ,,.ater shm.ved, that for HDR sources the mean ale'.batten ".'.'as-1.3±2,1%m air and +0,5± 2,0% m v.ater and for PDR sources -2.1±3.5% in air and -4.7± 2.2% in water The comparative measurements in air and in perspex showed, that for HDR sources the mean deviation was -2,5±1,6% in air and -0.7+_0.4% m perspex and for PDR sources +2.1+_2.1% tn air and +2.4_+1.4% m perspex The mean standard deviation bet,s.ten the series per source ~as 1%. In all the series the measurements were performed three times The mean standard deviation was 0,3% Conclusion: The results show. that there are ddl'erences in the results as a fimctlon of the phantonl material and that measurements m air sho'¢. for PDR sources larger deviations than HDR sources The chmcal relevance of the dam is. as the prescribed dose for the patients ts proponlorml to the air kerma, thai the specification of the absolute dose has It be seen ~ath the e~alualed maccuracy
WJF
A d v a n c e d volumetric i m a g i n g with C T - S c a n n e r and display technology (Silicon G r a p h i c s " ) were m e r g e d ~vith physical parameters collected in order to preplan and test reproducibility of implantation using rigid needles, tubes or moulds. Real time guidance under U S can be used in situ to i m p r o v e accuracy p e r f o r m i n g placement o f rigid vectors, plastic tubes or intracavitary m o u l d s and enhance the precision o f the procedure. Perioperative procedures can be p e r f o r m e d with a s s e s s m e n t o f geometric accuracy by refering to fiducial skin m a r k e r s on the skin and to C'I" controls. (Other potential sites o f interest arc under evaluation). Important planning tools such as dose v o l u m e histograms, i m a g e d security m a r g i n s including i m a g e distortions, registrations of patient anatomy.target v o l u m e localization and artifacts introduced by applicators need to be analysed for validation. M o r e patients are needed before any routine practice can be r e c o m m e n d e d . C o n c l u s i o n s : T h o u g h preliminary results s h o w very good c o v e r a g e o f the desired target v o l u m e , additionnal assessment must be analysed as '~irtual reality' doest not .~ct guarantee a u t o m a t i c a l b 'physical realit}'in real time.
113
114
Development of a navigation system for needle application in interstitial brachytherapy
Ineer-inltltutional i u r v o y on procedures for n r & c h ~ h e z a p ¥ Neeherl~nds
G. Stral~mann, C. Kolotas, R. Heyd, T. Martin, H. Vogt, N. Zamboglou Sttldt. Kliniken Offenbach, Slrahlentherapie
IKK K o l k m a n - D e u r l o o , A Riinders. AHL Aalbers, Dries, MA Moerland, B Schaeken, JLM V e n s e l a a r The N e t h e r l a n d s / B e l g i u m
Introduction: The quality of interstitial brachytherapy depends on the precision of needle placing. The task for a qualified needle application depends on the tumor geometry. The aim was to construct a CT-supportet navigation system, based on electro-magnetism measurement, which allows exact needle placing and its reconstruction. Material and Methods: With the help of a 3-D-digitizer the coordinates( as for instance the top of needle) are measured in space and projected in the prepared CT-siices. In the CT-slices, the prospectiv stitch canal of the needles can be simulated.The software, which is needed for this, was programmed in WINDOWS-NT with VISUAL C++. This makes it possible to be furthermore in direct network connection with the planing system. After needle application the needle reconstruction is possible with the same system. The needle geometry get afterwards transfered directly to the planing system. Results and discussion: In our experiment the accuracy of the needle application was measured between 2-4mm +/0,75mm, the accuracy of needle reconstruction between 24,5mm +/- 0,75ram. In spite of the electromagnetic function of our system, the disturbig influence of the metal needles can be neglected. During intraoperative applications the system can be handled by speech recognition. Conclusion: Our navigation system allows an exact "free hand"-application by means of preceding CT-diagnostics in the interstitial brachvtherapy.
Quality Control (QC) ~n B o l ~ i u m skid The
Introduction: T h e N e t h e r l a n d s C o m m i s s i o n on Radiation D o s i m e t r y (NCS) has p u b l i s h e d reports on dosim e c r y and QC p r o c e d u r e s of r a d i o a c t i v e sources used in b r a c h y t h e r a p y (BT) a n d c a l i b r a t i o n of Ir-192 HDR sources (reports 4 and 7). A n e w task group of the NCS, in c o o p e r a t i o n w i t h the B e l g i a n A s s o c i a t i o n of Hospital P h y s i c i s t s (BVZF/SBPH), has i n i t i a t e d the d e v e l o p m e n t and i m p l e m e n t a t i o n of g u i d e l i n e s for QC of b r a c h y t h e r a p y equipment in The N e t h e r l a n d s and Belgium. Material and methods: In a first phase it was dec i d e d to e v a l u a t e the c u r r e n t p r a c t i c e regarding QC p r o c e d u r e s for BT by m a i l i n g a q u e s t i o n n a i r e to all institutes performing BT in B e l g i u m (21) and The N e t h e r l a n d s (19). In a d d i t i o n to an i n v e n t o r y of BT e q u i p m e n t and BT p r o c e d u r e s p e r f o r m e d in 1996, it addressed the current QC procedures regarding safety systems, afterloaders, localization equipment and source c a l i b r a t i o n . Results: The s u r v e y d e m o n s t r a t e s a high incidence of HDR and PDR afterloaders, with the frequency of QC p r o c e d u r e s dominated by the f r e q u e n c y of the s o u r c e exchange. The most f r e q u e n t l y used m e t h o d of implant reconstruction makes use of a simulator, w i t h a few z n s t i t u t e s r e p o r t i n g the use of CT for target d e l i n e a t i o n . The QC of the r e c o n s t r u c t i o n procedure is u s u a l l y limited to the regular mechanical checks of the simulator with specific tests ( r e c o n s t r u c t i o n of a k~own implant geometry) only d u r i n g acceptance testing, e.g. of new releases of the t r e a t m e n t p l a n n i n g system. A more extensive a n a l y s i s of the results of this s u r v e y with special r e f e r e n c e to QC frequencies and tolerances will he discussed. Discussion: In a next step this s u r v e y will be completed by an i n t e r c o m p a r i s o n of the c o m p l e t e BT p r o c e d u r e using d e d i c a t e d phantoms and on site visits to e v a l u a t e the overall p r e c i s i o n in dose delivery with the d i f f e r e n t BT systems used in BelaJum and The Netherlands.
115
116
Accuracy of source strength measurements for Irldium-192.
3 D \,'irtual plannine stud', m the manao_emcnt of hrachytherap3 C e s i u m " - I n d i u m 1~: Palladium ' ~ i m p l a n t s
C
Fellner. R Potter AKH Vienna. Umversity Department for Radiotherapy and Radlobiology, Vienna. AUSTRIA
Burette R. ( M D ) . V a n D y c k e M. (Ph.vs) C 1 S t Jean - Radiotherapy & Brachytherapy Department- 114 rue du Marais - 1000 B R U S S E L S D C - B e l g i u m -
Introduction: The basis ofevery treatment of a patient as the knmdedge of the source strength in terms of the air kerma rate In the certificate of the manufacturer the air kerma for Indium-192 sources is specified with an inaccurac.', of ±10% The ann of this stud.'. ".','as to exanune these '~alues and to compare measurements of the air kerma ,.,.lth iomsanon cbambers in air. ~.aler and perspex Material and method: For our ~.vo HDR and tw'o PDR aflerloadmg machines from Nucletron v.e use sources manufactured b?. Malhnckrodt Between September 1993 and December 1997 v.e performed for 30 HDR and 22 PDR sources dosimemc measurements v..ith 13.9e 2571 iomsatlnn charters from P'I"3,V The measurements ,.,.ere done wdh an 'in-air" phantom. V.lth a small water phantom or vdth a phantom made out of perspex. For the 30 HDR sources 83 measurement series and for the 22 PDR sources 82 senes were performed m air For 7 HDR and 5
Since 97. for patients ~ith early breasts cancers It '~: brachytherapy boost, H & N . prostate, gynecological and anorectal tumors, we developped T P S m e t h o d o l o g 3 (Plato °) on a pre-treatment virtual simulation. Paris S3stcm rules were followed and dose v o l u m e delive R" studied & c h e c k e d for rcproducibdily.
PDR sourcescompasat*vemeasurements~re performed m au and m water For 4 HDR and 4 PDR sourcescomparativemcasurcmentst~crc performed in air and in perspex Results: The mean deviation between the kerma specified in the cemficale and the measured kerma in air for the 30 HDR sources was u,6±2.5% ( I o) and for 22 PDR sources -4,4+_3,3% The comparative measurements in air and in ,,.ater shm.ved, that for HDR sources the mean ale'.batten ".'.'as-1.3±2,1%m air and +0,5± 2,0% m v.ater and for PDR sources -2.1±3.5% in air and -4.7± 2.2% in water The comparative measurements in air and in perspex showed, that for HDR sources the mean deviation was -2,5±1,6% in air and -0.7+_0.4% m perspex and for PDR sources +2.1+_2.1% tn air and +2.4_+1.4% m perspex The mean standard deviation bet,s.ten the series per source ~as 1%. In all the series the measurements were performed three times The mean standard deviation was 0,3% Conclusion: The results show. that there are ddl'erences in the results as a fimctlon of the phantonl material and that measurements m air sho'¢. for PDR sources larger deviations than HDR sources The chmcal relevance of the dam is. as the prescribed dose for the patients ts proponlorml to the air kerma, thai the specification of the absolute dose has It be seen ~ath the e~alualed maccuracy
WJF
A d v a n c e d volumetric i m a g i n g with C T - S c a n n e r and display technology (Silicon G r a p h i c s " ) were m e r g e d ~vith physical parameters collected in order to preplan and test reproducibility of implantation using rigid needles, tubes or moulds. Real time guidance under U S can be used in situ to i m p r o v e accuracy p e r f o r m i n g placement o f rigid vectors, plastic tubes or intracavitary m o u l d s and enhance the precision o f the procedure. Perioperative procedures can be p e r f o r m e d with a s s e s s m e n t o f geometric accuracy by refering to fiducial skin m a r k e r s on the skin and to C'I" controls. (Other potential sites o f interest arc under evaluation). Important planning tools such as dose v o l u m e histograms, i m a g e d security m a r g i n s including i m a g e distortions, registrations of patient anatomy.target v o l u m e localization and artifacts introduced by applicators need to be analysed for validation. M o r e patients are needed before any routine practice can be r e c o m m e n d e d . C o n c l u s i o n s : T h o u g h preliminary results s h o w very good c o v e r a g e o f the desired target v o l u m e , additionnal assessment must be analysed as '~irtual reality' doest not .~ct guarantee a u t o m a t i c a l b 'physical realit}'in real time.