장은성 *, 백성민 **, 고성진 ***, 강세식 *** 고신대학교복음병원방사선종양학과 *, 고신대학교복음병원핵의학과 **, 부산가톨릭대학교방사선학과 *** Eunsung Jang *, Seongmin Baek **, Seungjin Ko ***, Se-Sik kang *** Dept. Radiation Oncology *, Nuclear ** Gosin University Gospel Hospital Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan *** (image guided radiation therapy: IGRT) skin marker 2 OBI(on board imager) couch set up,. 27 DRR(digital reconstructed radiography) OBI 2-2 (2D-2D matching). Head&Neck Spinal cord OBI, Chest Abdomen& Pelvic 23. OIS(oncology information system) 6 Head&Neck, Chest Abdomen&Pelvic. Head&Neck AP, SI, RL ± cm, -.±. cm, -±. cm, Chest -.5±. cm,.3±.3 cm, ± cm Abdomen ±cm, -.5±.cm, -±.cm. Pelvic.5±.3 cm, ± cm, -.3± cm. Head&Neck (rigid body) Chest Abdomen. Chest, Abdomen&Pelvic AP. Chest, Abdomen AP. systematic error. OBI. 2-2 3-3 rolling 2-2. When using Image Guided Radiation Therapy, the patient is placed using skin marker first and after confirming anatomical location using OBI, the couch is moved to correct the set up. Evaluation for the error made at that moment was done. Corresponding Author: 장은성 주소 : 부산금정구장전동부산대학교제 물리관핵물리하드론연구싈 7, E-mail: silver966@naver.com, Tel: +82--4789-3548 투고일자 : 29 년 4 월 2 일, 심사일자 : 29 년 6 월 3 일, 수정일자 : 29 년 8 월 8 일, 게재확정일자 : 29 년 9 월 5 일
Through comparing and 27 direction DRR image and OBI image with 2D-2D matching when therapy planning, comparison between patient s therapy plan setup and actual treatment setup was made to observe the error. Treatment confirmation on important organs such as head, neck and spinal cord was done every time through OBI setup and other organs such as chest, abdomen and pelvis was done 2 ~ 3 times a week. But corrections were all recorded on OIS so that evaluation on accuracy could be made through using skin index which was divided into head, neck, chest and abdomen-pelvis on 6 patients. Average setup error for head and neck patient on each AP, SI, RL direction was ± cm, -.±. cm, -±. cm, chest patient was -.5±. cm,.3±.3 cm, ± cm, and abdomen was ±cm, -.5±.cm, -±.cm. In case of pelvis, it was.5±-.3 cm, ± cm, -.3± cm. In rigid body parts such as head and neck showed lesser setup error compared to chest and abdomen. Error was greater on chest in horizontal axis and in AP direction, abdomen-pelvis showed greater error. Error was greater on chest in horizontal axis because of the curve in patient s body when the setup is made. Error was greater on abdomen in AP direction because of the change in front and back location due to breathing of patient. There was no systematic error on patient setup system. Since OBI confirms the anatomical location, when focus is located on the skin, it is more precise to use skin marker to setup. When compared with 3D-3D conformation, although 2D-2D conformation can t find out the rolling error, it has lesser radiation exposure and shorter setup confirmation time. Therefore, on actual clinic, 2D-2D conformation is more appropriate. key word :, OBI,,,, IGRT(Image Guided Radiation Therapy), OBI(on board imager), Image matching, Setup error, Treatment center Ⅰ. (intensity modulated radiation therapy: IMRT), [-5]. (inter-fractional error), (planning target volume: PTV), [6,7]. kv X MV X (cone beam computerize-d tomogra phy: CBCT) (Fig. ), Tomothera py [8,9] (image- guided rad-iation therapy: IGRT) [8]. OBI kv X DRR 2 OBI. Ⅱ. - IGRT(Clinac ix, Varian, USA) - Eclipse (Varian Medical Systems, USA) - On-Board Imager (OBI) (Varian Medical Systems, Palo Alto, CA) - OBI or CBCT Console Wokrspace(Varian Medical Systems, USA)
., DRR (bone). (Fig. 2)., DRR OBI kv X, OBI (shift),. Fraction Site Patient Treated Imaged Head& Neck 4 28 9 ) Setup CT. OBI kv X 2-2 27 (Fig. 2). Head&Neck OBI, Chest Abdomen 23. Spinal cord. OIS 6 Head&Neck, Chest Abdomen&Pelvic (Table ). Chest 4 28 Abdomen 4 28 Pelvis 4 28 2) (Shift) CT (AP, Lateral) OBI kv X 2-2
MANUAL MATCHING AUTOMATIC MATCHING ACQUIRE ANALYZE 2D/2D MATCH APPLY SHIFT Lat image acq. Ant image acq. Ⅲ. Setup Fig. 47 Table 2.. DRR 2,. Head&Neck Chest & Abdomen. Head&Neck RL, AP, SI ± cm, -.±. cm, -±. cm, Chest -.5±. cm,.3±.3 cm, ± cm Abdomen ±cm, -.5±.cm, -±.cm Pelvic.5±.3 cm, ± cm, -.3± cm. Chest Abdomen& Pelvic AP..,.
AP-SI AP- RL AP-SI AP- RL - - - - -.... -.8.6.4.2 2 4 6 8 - - - - -. 8 -. 6 -. 4-2 - - - -.5 - -. -. -. -. 8 6 4 -.5 2 - - - - - - - - - - - RL-SI RL-SI - - - - - - - - - - - - - - - - - - AP-SI AP-RL AP- SI AP-RL - - - - - - - - -. -. -. -. - 8 6 4 2 - - - - - - - - - - - - - - - - - - - - - - - - - - - SI-RL SI-RL - - - - - - - - - - - -. -. -. -. - 8 6 4 2 - - - -
Site RL AP SI Head&Neck ± -.±. -±. Chest -.5±..3±.3 ± Abdomen ± -.5± -±. Pelvis.5±.3 ± -.3± Ⅳ.. OBI, OBI kv X (kv, 27 ) 2-2. kv X., kv X Head & Neck RL, AP, SI ± cm, -.±. cm, -±. cm Chin ( ), Chest -.5±. cm,.3±.3 cm, ± cm,, Abdomen ±cm, -.5±.cm, -±.cm, AP. Pelvic.5±.3 cm, ± cm, -.3± cm,. OBI. cm,.35 cm,.3 cm [,]., OBI kv X. (systematic error). OBI. 2-2 3-3,,, 2-2. Head & Neck, Chest.. Abdomen AP. Pelvic,., OBI. Ⅴ (systematic error). OBI. 2-2 3-3,,, 2-2
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