Korean J Med Phys.
2011 Dec;22(4):206-215.
A Pilot Research for Real-Time Specific Patient Quality Assurance Using the Hybrid Optimized Vmat Phantom (Hovp) in Volume Modulated Arc Therapy
- Affiliations
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- 1Department of Radiation Oncology, College of Medicine, Inha University, Incheon, Korea.
- 2Department of Nuclear Engineering, Hanyang University, Seoul, Korea.
- 3Department of Radiation Oncology, College of Medicine, Hanyang University, Seoul, Korea.
- 4Department of Radiation Oncology, College of Medicine, Eulji University, Seongnam, Korea.
- 5Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Seoul, Korea.
- 6Department of Radiation Oncology, Cheil General Hospital, Kwandong University College of Medicine, Gangneung, Korea.
- 7Department of Radiation Oncology, College of Medicine, Korea University, Seoul, Korea.
- 8Department of Radiation Oncology, School of Medicine, Kyung Hee University, Seoul, Korea.
- 9Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul, Korea. jyh328@kirams.re.kr
Abstract
- The purpose of this was to investigate the measurement of fluence dose map for the specific patient quality assurance. The measurement of fluence map was performed using 2D matrixx detector. The absorbed dose was measured by a glass detector, Gafchromic film and ion chamber in Hybrid Optimized VMAT Phantom (HOVP). For 2D Matrixx, the results of comparison were average passing rate 85.22%+/-1.7 (RT_Target), 89.96%+/-2.15 (LT_Target) and 95.14%+/-1.18 (G4). The dose difference was 11.72%+/-0.531, -11.47%+/-0.991, 7.81%+/-0.857, -4.14%+/-0.761 at the G1, G2, G3, G4. In HOVP, the results of comparison for film were average passing rate (3%, 3 mm) 93.64%+/-3.87, 90.82%+/-0.99. We were measured an absolute dose in steep gradient area G1, G2, G3, G4 using the glass detector. The difference between the measurement and calculation are 8.3% (G1), -5.4% (G2), 6.1% (G3), 7.2% (G4). The using an Ion-chamber were an average relative dose error -1.02%+/-0.222 (Rt_target), 0.96%+/-0.294 (Lt_target). Though we need a more study using a transmission detector. However, a measurement of real-time fluence map will be predicting a dose for real-time specific patient quality assurance in volume modulated arc therapy.