초록 ▼

● 기능, 대사영상 치료융합 기반 및 응용기술 개발
- 전립선 및 뇌 종양 환자에 대해 기능/대사영상을 획득하여 방사선 치료계획을 세움으로써, 종양의 margin을 명확히 하고 정상조직에 대한 complication을 최소화하여 방사선 치료의 효율을 높임. 또한 MRI/CT/PET에서 동시 사용 가능한 차세대 융복합 팬톰을 개발함으로써, 다중영상기기들의 핵심 QA항목들을 동시 평가하여 시간적/경제적 절감 효과를 얻음.
● 동적영상 및 영상정합을 이용한 치료 융합기술 개발
- 호흡신호를 이용한 4D CT영상 재구성을

● 기능, 대사영상 치료융합 기반 및 응용기술 개발
- 전립선 및 뇌 종양 환자에 대해 기능/대사영상을 획득하여 방사선 치료계획을 세움으로써, 종양의 margin을 명확히 하고 정상조직에 대한 complication을 최소화하여 방사선 치료의 효율을 높임. 또한 MRI/CT/PET에서 동시 사용 가능한 차세대 융복합 팬톰을 개발함으로써, 다중영상기기들의 핵심 QA항목들을 동시 평가하여 시간적/경제적 절감 효과를 얻음.
● 동적영상 및 영상정합을 이용한 치료 융합기술 개발
- 호흡신호를 이용한 4D CT영상 재구성을 최적화하고, 동적장기 영상의 deformable registration 모듈을 개발함. 개발된 모듈을 이를 팬톰 및 임상데이터에 적용/테스트하여 유용성을 검증함. 또한 MR 기능영상 (확산영상-ADC map)을 이용하여 종양특징 파라미터를 추출함. 추출된 종양특징 파라미터를 중심으로 방사선치료계획을 수립하여, 이를 기존의 CT-based 방사선치료계획과 비교분석함.
● 3D/4D 다중영상기반 생물학적 최적화 방사선 치료기술 개발
- 확산강조영상을 이용하여 종양볼륨을 시각화하고, mutual information을 이용하여 종양볼륨을 분할함. 또한 장기움직임을 고려한 hypoxic tracer PET 영상을 획득 및 최적화 기술을 개발하고, PET과 확산영상 및 T2 영상의 정합을 통해 종양볼륨을 비교분석함. 영상융합하여 분석한 PET과 CT영상에서 time phase analysis 변화에 따른 hysteresis 분석함.
● 다중영상기반 방사선수술의 병리를 고려한 병소체적 결정 프로토콜 및 최적치료계획조건 개발
- 방사선수술장비들의 팬톰을 이용하여 병소체적을 측정하고, 그에 대한 오차를 분석함. 또한 질환별 치료계획에서 영상융합 체적 결정방법을 비교/분석하고, 확산텐서 섬유로 영상을 이용하여 치료계획 체적 결정방법을 비교함. 그리고 Monte Carlo simulation을 이용하여 방사선수술장비의 선량전달 정확도를 검증하고, 방사선수술영상의 왜곡 형태별 보완방법을 개발함.

Abstract ▼

Ⅳ. Research Results
1. Development of metabolic / functional MR image-based radiation treatment planning techniques
● Radiation treatment planning was performed using MR spectroscopic imaing (MRSI) in prostate cancer patients. The target volumes were contoured in region of elevated metabolic l

Ⅳ. Research Results
1. Development of metabolic / functional MR image-based radiation treatment planning techniques
● Radiation treatment planning was performed using MR spectroscopic imaing (MRSI) in prostate cancer patients. The target volumes were contoured in region of elevated metabolic level in MRSI.
● We developed fusion phantom that allow us to evaluate image registration accuracy. And the fusion phantom can be used in MRI-PET or PET-CT system.
● The functional MRI (i.e., BOLD EPI) that contains the information for movement / sensory nerve can be applied to brain tumor patients. We developed basic practices to include fMRI　information in radiation treatment planning.
● We exploited a graphic user interface (GUI) that is linked to LCModel software.
The GUI can import the output files (i.e., "Coord") of LCModel, and automatically calculate metabolic map. The calculated metabolic map can be overlaid with anatomical MR image (i.e., T1/T2 image).
● We developed an image registration toolkit (Matlab-based GUI) that can import multi-modality images (i.e, CT, MRI, MRSI) simultaneously.
● The polymer gel phantom that allow us to confirm 3D dose distribution was developed.
● The metabolic/functional MR image-based radiation treatment planning allow us to define tumor margin more accurately. That results in reducing normal tissue complications, thus improving radiotherapeutic efficiency.
2. Development of radiation treatment techniques using dynamic image and image registration
● Developed the optimization technique reducing motion artifact in 4DCT image and evaluate the image quality using the irregular respiratory signal.(applying 5 case)
● Performance evaluation of Optical flow and B-spline deformable registration algorithm under C++ language.
● Analysis of the 4DCT image affected by motion artifact using the phantom which could control target motion patterns and amplitude(applying 6 case).
● Developed the phantom for an accuracy verification and obtain the data that 0.4 mm accuracy under the case of 10 mm amplitude.
● Carry out the image registration and ADC, rCBV information mapping at the CT / MR functional fusion image(applying 3 case) and conduct comparison study of IMRT plan by using the factor of DVH and NTCP.
3. Advanced research of optimized biological radiation treatment techniques based on multimodal imaging
● Optimized protocol is verified by analysis of biological image characteristics based on multimodal imaging for establishment of quantitative radiation treatment planning to apply cancer patients in radiation therapy and radiosurgery.
● Tumor volume optimization is implemented by characteristic parameters of metabolic images as being analysis of biological image characteristics based on multimodal imaging, and optimized technique for tumor volume is implemented to concern about fiber track in tractography.
4. Fundamental research of optimized biological radiation treatment techniques based on 4D multimodal imaging
● Tumor volume after image fusion is compared by analysis of dynamic PET in 4D PET/CT concerned organ motion, and tumor model for respiratory period in analysed PET and CT images result in to tumor volume applied respiratory period and hysteresis of tumor motion by image fusion.
● Optimized characteristic parameters can be applied useful to accurate radiosurgery and radiation treatment using GTV applying normalized mutual information method after acquisition of respiratory signal in 4D dynamic PET/CT.
● Optimized radiosurgery and radiation treatment is applied by tumor volume optimization based on multimodal imaging such as diffusion images, metabolic images, and T2-weighted images extracting tumor characteristic parameters of metabolic image using 4D dynamic PET/CT.
5. Development of an optimal protocol for multi-modality image-based tumor volume definition in radiosurgery
● We developed multi-modality image fusion techniques according to lesions.
● We developed MRI/CT/Angio compatible phantom with function for simulating brain blood vessel.
● We provided the data for registration accuracy between multi-modality images in BrainSCAN and Pinnacle software that have been widely used in radiosurgery planning system.
● We suggested image fusion protocol for treatment of AVM and pituitary tumor in radiosurgery.
6. Development of optimal conditions for mutli-modality image-based radiosurgery
● We validated the radiation delivery accuracy in radiosurgery system using phantom and Monte Carlo simulation.
● We exploited the technique for image geometric distortion correction using phantom.