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Treatment planning of stereotactic brain implants using an interactive graphical system
291
Proceedings of the 34th Annual ASTRO Meeting Results : With the previous methodology, based mainly on the selective calculation, used by our group in the 1986-1989 period overall obliteration results on 46 patients treated with our new associated targets methodology been done in 35 cases, Overall obliteration rate is 25/35 (71.4 %). For one multi-isocenters AVMs it is lo/16 (62.5%).
irradiation of critical focus inside the nidus and 2-D dose rate was 351104 (33.7%). We present our preliminary 1990 and dose-volume analysis. So far arteriography control has isocenter I9 AVMs obliteration rate is 1_5/19(78%). For 16
Conclusion : With our new methodology, used since January 1990, we have improved the results obtained during the first years of our radiosurgical practice. We feel that complex AVMs treatment has greatly benefited from the combination of the associated targets methodology and the treatment planning ARTEMIS-3D.
1088 ACCURACY
OF CT SIMULATION
Toshiya Sakaguchi,M.D. Takeyuki Kushima,M.D. Department of Radiology
SYSTEM
IN APPLICATION
, Kazufumi Imanaka,M.D. ,Michio Kono,M.D. , , Kobe University School
, Kazuyuki of Medicine
TO STEREOTACTIC
Yonezawa,M.D.
RADIOSURGERY
,
, Japan
We evaluate the accuracy of CT simulation system in application to stereotactic radiosurgery Purpose; combined with linear accelerator. Materials and Methods; CTSS consists of CTscanner ( GE9800 Highlight ) , work station and laser marking system ( Yokogawa Medical System ) Phantom with target was scanned with 3 mm slice thickness , 3 mm interval, and a image was displayed with 256 x 256 matrix . Images were transferred to work station to determine the coordinate of target isocenter . After marking the position of isocenter with laser marking system, phantom was put on the table to correspond the isocenter with the intersection of two axes, gantry and table. After that, irradiation was performed using 10 MV linear accelerator ( LINAC 20-MDX ) films were taken . Evaluation with auxiliary collimation system , and verification of accuracy of target localization and radiation delivery was as follows ( 1 ) Distance between true isocenter and calculated one with CTSS ( 2 ) Distance between center of the radiation field and isocenter of the target in various combination of gantry and table angle ( 3 ) Dose distribution curve obtained with film method Results ; Maximum distance between true and calculated isocen ter was 1.0 mm at X axis , 1.0 mm at Y axis and 1.5 mm at 2 axis respectively Distance between center of the radiation field and isocenter of the target was ranged from 0 to 2.0 mm ( 1.0 mm in average ) Excellent dose distribution was obtained in this system . Conclusions; CTSS accurately localized the coordinate of target isocenter , and accurate irradiation was performed using this system combined with CTSS and linear accelerator .
1089 TREATMENT PLANNINGOF STEREOTACTICBRAIN Breneman University
JC, of
Lamba M, Foster Cincinnati
A,
Hospital,
Elson
H,
Barrett
IFPLANTS USING AN INTERACTIVE Aron
GRAPHICAL SYSTEM
B
Cancer
Center,
Radiation
Oncology
Stereotactic implantation of radioactive sources is becoming increasingly important in the WRWSE : Most existing doslmetry software is of limited use for planning these management of intracranial tumors. lack of stereotactic localization implants because of the restriction to two-dimensional planning and A treatment planning system capablllties. Other planning systems are expensive and/or cumbersome to use. has been devised to overcome these drawbacks. Treatment planning software was written to run on an IBM compatible mlcroMATERIALS AN0 l4ETHODS: The program uses the Brown-Roberts-Wells (BRW) computer equipped with a mouse and digitizer tablet. stereotactlc system for spatial localization. A BRW localized CT scan Is digitlzed and orthogonal view Catheters and seeds can then be “drawn” in three dimensions on the digitized planes are reconstructed.
Proceedings of the 34th Annual ASTRO Meeting Results : With the previous methodology, based mainly on the selective calculation, used by our group in the 1986-1989 period overall obliteration results on 46 patients treated with our new associated targets methodology been done in 35 cases, Overall obliteration rate is 25/35 (71.4 %). For one multi-isocenters AVMs it is lo/16 (62.5%).
irradiation of critical focus inside the nidus and 2-D dose rate was 351104 (33.7%). We present our preliminary 1990 and dose-volume analysis. So far arteriography control has isocenter I9 AVMs obliteration rate is 1_5/19(78%). For 16
Conclusion : With our new methodology, used since January 1990, we have improved the results obtained during the first years of our radiosurgical practice. We feel that complex AVMs treatment has greatly benefited from the combination of the associated targets methodology and the treatment planning ARTEMIS-3D.
1088 ACCURACY
OF CT SIMULATION
Toshiya Sakaguchi,M.D. Takeyuki Kushima,M.D. Department of Radiology
SYSTEM
IN APPLICATION
, Kazufumi Imanaka,M.D. ,Michio Kono,M.D. , , Kobe University School
, Kazuyuki of Medicine
TO STEREOTACTIC
Yonezawa,M.D.
RADIOSURGERY
,
, Japan
We evaluate the accuracy of CT simulation system in application to stereotactic radiosurgery Purpose; combined with linear accelerator. Materials and Methods; CTSS consists of CTscanner ( GE9800 Highlight ) , work station and laser marking system ( Yokogawa Medical System ) Phantom with target was scanned with 3 mm slice thickness , 3 mm interval, and a image was displayed with 256 x 256 matrix . Images were transferred to work station to determine the coordinate of target isocenter . After marking the position of isocenter with laser marking system, phantom was put on the table to correspond the isocenter with the intersection of two axes, gantry and table. After that, irradiation was performed using 10 MV linear accelerator ( LINAC 20-MDX ) films were taken . Evaluation with auxiliary collimation system , and verification of accuracy of target localization and radiation delivery was as follows ( 1 ) Distance between true isocenter and calculated one with CTSS ( 2 ) Distance between center of the radiation field and isocenter of the target in various combination of gantry and table angle ( 3 ) Dose distribution curve obtained with film method Results ; Maximum distance between true and calculated isocen ter was 1.0 mm at X axis , 1.0 mm at Y axis and 1.5 mm at 2 axis respectively Distance between center of the radiation field and isocenter of the target was ranged from 0 to 2.0 mm ( 1.0 mm in average ) Excellent dose distribution was obtained in this system . Conclusions; CTSS accurately localized the coordinate of target isocenter , and accurate irradiation was performed using this system combined with CTSS and linear accelerator .
1089 TREATMENT PLANNINGOF STEREOTACTICBRAIN Breneman University
JC, of
Lamba M, Foster Cincinnati
A,
Hospital,
Elson
H,
Barrett
IFPLANTS USING AN INTERACTIVE Aron
GRAPHICAL SYSTEM
B
Cancer
Center,
Radiation
Oncology
Stereotactic implantation of radioactive sources is becoming increasingly important in the WRWSE : Most existing doslmetry software is of limited use for planning these management of intracranial tumors. lack of stereotactic localization implants because of the restriction to two-dimensional planning and A treatment planning system capablllties. Other planning systems are expensive and/or cumbersome to use. has been devised to overcome these drawbacks. Treatment planning software was written to run on an IBM compatible mlcroMATERIALS AN0 l4ETHODS: The program uses the Brown-Roberts-Wells (BRW) computer equipped with a mouse and digitizer tablet. stereotactlc system for spatial localization. A BRW localized CT scan Is digitlzed and orthogonal view Catheters and seeds can then be “drawn” in three dimensions on the digitized planes are reconstructed.