To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ±5%. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ±10% even though their total dose differences were less than ±5%. The difference in 3D dose gradients between the two groups was estimated in a cube of 6 × 6 × 6 mm3 centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 cGy․mm-1, respectively, while those of the examination group were 0.64, 0.48, and 0.28 cGy․mm-1, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.
목차
Abstract 1. INTRODUCTION 2. MATERIALS AND METHODS 3. RESULTS 4. DISCUSSION AND CONCLUSIONS REFERENCES
SO‐YEON PARK [ Department of Radiation Applied Life Science, Seoul National University Graduate School ]
JONG MIN PARK [ Department of Radiation Oncology, Seoul National University College of Medicine ]
SUNG‐JOON YE [ Department of Intelligent Convergence Systems, Graduate School of Convergence Science and Technology, Seoul National University ]
Cprresponding author
대한방사선방어학회 [Korean Association For Radiation Protection]
설립연도
1975
분야
자연과학>기타자연과학
소개
회원 상호간의 협조와 친목을 도모함으로써 방사선방어에 관한 제반연구 및 발전에 이바지함을 물론 학술의 국제교류 및 국제학술단체와의 상호협력 증진에 기여함을 목적으로 하며, 이 목적을 달성하기 위하여 다음 각 호의 사업을 한다.
1. 방사선방어에 관한 학술연구발표회 및 강연회 등의 개최
2. 학회지 및 방사선방어에 관한 학술간행물의 발행 및 배포
3. 방사선방어에 관한 학술의 국제교류 및 협력
4. 방사선방어에 관한 국제학술자료의 조사, 수집 및 번역
5. 방사선방어에 관한 조사 및 연구용역
6. 회원의 연구활동을 위한 제반협조
7. 기타 본 학회의 목적 달성에 필요한 사항
간행물
간행물명
방사선방어학회지 [Journal of Radiation Protection and Research]