• 대한두경부종양학회지
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• 제4권1호
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• pp.5-11
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• 1988

CT examination has been used in the preoperative examination of patients with head and neck cancer. The accuracy of CT in detecting nodal metastases has not been well established. We studied 35 patients (41 neck specimens) with head and neck cancer who underwent neck dissection. Surgical pathologic findings were compared with preoperative CT scan to establish the diagnostic accuracy for cervical lymph node metastases. The results of physical examination, CT scans of neck and histologic examinations were compared each other. The overall diagnostic accuracy of CT was 83.3%. Comparison with clinical accuracy shows the CT scan to be superior to the clinical examination in spite of careful physical examination, particularly in detecting occult metastases.

• Journal of Korean Neurosurgical Society
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• 제54권2호
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• pp.100-106
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• 2013

Objective : To investigate the cases of intracranial abnormal brain MRI findings even in the negative brain CT scan after mild head injury. Methods : During a 2-year period (January 2009-December 2010), we prospectively evaluated both brain CT and brain MRI of 180 patients with mild head injury. Patients were classified into two groups according to presence or absence of abnormal brain MRI finding even in the negative brain CT scan after mild head injury. Two neurosurgeons and one neuroradiologist validated the images from both brain CT scan and brain MRI double blindly. Results : Intracranial injury with negative brain CT scan after mild head injury occurred in 18 patients (10.0%). Headache (51.7%) without neurologic signs was the most common symptom. Locations of intracranial lesions showing abnormal brain MRI were as follows; temporal base (n=8), frontal pole (n=5), falx cerebri (n=2), basal ganglia (n=1), tentorium (n=1), and sylvian fissure (n=1). Intracranial injury was common in patients with a loss of consciousness, symptom duration >2 weeks, or in cases of patients with linear skull fracture (p=0.00013), and also more frequent in multiple associated injury than simple one (35.7%>8.6%) (p=0.105). Conclusion : Our investigation showed that patients with mild head injury even in the negative brain CT scan had a few cases of intracranial injury. These findings indicate that even though the brain CT does not show abnormal findings, they should be thoroughly watched in further study including brain MRI in cases of multiple injuries and when their complaints are sustained.

• 대한방사선치료학회지
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• 제27권2호
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• pp.131-143
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• 2015

목 적 : MRI를 기반으로 한 CT fusion plan과 MRI only based plan을 비교함으로써 MRI only plan의 유용성을 평가하고, 나아가 Simulation과 치료계획을 포함한 방사선치료의 전 과정을 CT 촬영 없이 MRI 영상으로 구성하여 실시간 MR-IGRT를 구현하고자 한다. 대상 및 방법 : 본원에서 사용중인 BBB CT (Brilliance Big Bore CT, 16slice, Philips)와 Viewray MRIdian System (Viewray, USA)으로 환자 11명(Head and Neck 1명, Breast 5명, Lung 1명, Liver 3명, Prostate 1명)을 대상으로 CT & MR simulation 및 치료계획을 세웠다. Head and Neck, Breast, Prostate환자는 자유호흡(Free Breathing) 상태로, Lung과 Liver 환자는 흡기 호흡중지(Inhalation Breathing Holdng)상태로 Simulation을 진행하였다. Viewray의 Bore 크기 및 Coil 위치를 고려하여 환자 자세 및 고정기구를 동일한 조건을 유지하여 CT simulation을 시행하였다. Viewray MRIdian 시스템을 이용하여 MR 영상을 기반으로 한 CT fusion plan과 CT fusion 없이 [ICRU 46]에서 권고하는 폐, 공기, 뼈의 전자밀도를 입력한 동일한 조건의 MR only plan을 세웠다. Head and Neck, Breast, Prostate는 IMRT, Lung과 Liver 는 Gating치료계획을 세웠고, 치료계획의 평가는 PTV의 균질성 지표 (Homogeneity Index, HI)와 일치성 지표 (Conformity Index, CI), 그리고 각 PTV와 OAR의 DVH와 선량차이를 각각 비교하였다. 결 과 : 두 치료계획간 치료부위별 PTV에 대한 HI 값의 차이는 Head and Neck, Breast, Lung, Liver, Prostate 부위별로 각각 0.089, 0.26, 0.67, 0.2, 0.4%로 나타났으며, CI 값의 차이는 부위별로 각각 0.043, 0.84, 0.68, 0.46, 0.3%로 두가지 평가 값 모두 Head and Neck 부위가 가장 작은 차이를 나타냈다. PTV에 대한 평균선량 차이는 치료부위별로 각각 0.07, 0.29, 0.18, 0.3, 0.18 Gy로 나타났다. 이를 백분율로 나타냈을 때 0.06, 0.7, 0.29, 0.69, 0.44%으로 모두 1% 이하의 차이를 보였다. 두경부암의 각 OAR은 전체적으로 0.01~0.12 Gy의 평균선량 차이를 보였으며, 유방암은 0.04~0.06 Gy, 폐암에서는 0.01~0.21 Gy, 간암은 0.06~0.27 Gy, 전립선암은 0.02~0.23 Gy의 평균선량 차이를 나타냈다. 결 론 : MR 영상을 이용한 치료계획은 연부조직에서 탁월한 대조도를 나타낼 뿐만 아니라 CT fusion한 MR 치료계획과 비교했을 때 PTV의 HI, CI, 선량차이 모두 1%미만의 차이를 보였으며, OAR의 경우 비균질한 조직이 많은 부위일수록 최대 0.89 Gy 선량차이를 보였다. 이결과를 토대로 두경부암, 부분적 유방암이나 전립선암등 비균질도 차이가 적은 부위에는 CT촬영 없이 MR 영상만을 이용한 방사선치료의 가능성을 확인 할 수 있었다.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.303-314
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• 2023

This study aimed to assess the practical feasibility of advanced deformable image registration (DIR) algorithms in radiotherapy by employing two distinct datasets. The first dataset included 14 4D lung CT scans and 31 head and neck CT scans. In the 4D lung CT dataset, we employed the DIR algorithm to register organs at risk and tumors based on respiratory phases. The second dataset comprised pre-, mid-, and post-treatment CT images of the head and neck region, along with organ at risk and tumor delineations. These images underwent registration using the DIR algorithm, and Dice similarity coefficients (DSCs) were compared. In the 4D lung CT dataset, registration accuracy was evaluated for the spinal cord, lung, lung nodules, esophagus, and tumors. The average DSCs for the non-learning-based SyN and NiftyReg algorithms were 0.92±0.07 and 0.88±0.09, respectively. Deep learning methods, namely Voxelmorph, Cyclemorph, and Transmorph, achieved average DSCs of 0.90±0.07, 0.91±0.04, and 0.89±0.05, respectively. For the head and neck CT dataset, the average DSCs for SyN and NiftyReg were 0.82±0.04 and 0.79±0.05, respectively, while Voxelmorph, Cyclemorph, and Transmorph showed average DSCs of 0.80±0.08, 0.78±0.11, and 0.78±0.09, respectively. Additionally, the deep learning DIR algorithms demonstrated faster transformation times compared to other models, including commercial and conventional mathematical algorithms (Voxelmorph: 0.36 sec/images, Cyclemorph: 0.3 sec/images, Transmorph: 5.1 sec/images, SyN: 140 sec/images, NiftyReg: 40.2 sec/images). In conclusion, this study highlights the varying clinical applicability of deep learning-based DIR methods in different anatomical regions. While challenges were encountered in head and neck CT registrations, 4D lung CT registrations exhibited favorable results, indicating the potential for clinical implementation. Further research and development in DIR algorithms tailored to specific anatomical regions are warranted to improve the overall clinical utility of these methods.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10899-10903
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• 2015

Background: In this study, we aimed to investigate the benefits of 18F-deoxyglucose positron emission tomography/computed tomography (FGD-PET/CT) imaging for staging and radiotherapy planning in patients with head and neck cancer undergoing definitive radiotherapy. Materials and Methods: Thirty-seven head and neck cancer patients who had undergone definitive radiotherapy and PET/CT at the Uludag University Medical Faculty Department of Radiation Oncology were investigated in order to determine the role of PET/CT in staging and radiotherapy planning. Results: The median age of this patient group of 32 males and 5 females was 57 years (13-84years). The stage remained the same in 18 cases, decreased in 5 cases and increased in 14 cases with PET/CT imaging. Total gross tumor volume (GTV) determined by CT (GTVCT-Total) was increased in 32 cases (86.5%) when compared to total GTV determined by PET/CT (GTVPET/CT-Total). The GTV of the primary tumor determined by PET/CT (GTVPET/CT) was larger in 3 cases and smaller in 34 cases compared to that determined by CT (GTVCT). The GTV of lymph nodes determined by PET/CT (GTVLNPET/CT) was larger in 20 cases (54%) and smaller in 12 cases (32.5%) when compared to GTV values determined by CT (GTVLNCT). No pathological lymph nodes were observed in the remaining five cases with both CT and PET/CT. Conclusions: We can conclude that PET/CT can significantly affect both pretreatment staging and assessed target tumor volume in patients with head and neck cancer. We therefore recommend examining such cases with PEC/CT before treatment.

• 대한두경부종양학회지
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• 제32권2호
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• pp.85-89
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• 2016

Pleomorphic adenomas is the most common tumor of parotid gland and usually located and confined in superficial lobe of parotid gland. Computed tomography (CT) is commonly used to initially evaluate salivary gland lesion, but contrast-enhanced CT may sometimes fail to reveal lesions in spite of a high clinical suspicion. For this reason, ultrasonography (US) can be used as the first-line image work-up in some cases of parotid gland benign tumors. We experienced a case of a 60-year-old woman without underlying disease presenting a palpable parotid mass in which the initial CT examination was reported as 'no obvious mass detected'. However, the lesion was revealed in US and histologically confirmed as pleomorphic adenoma. The patient underwent superficial parotidectomy through modified facelift incision. To the best of our knowledge, this is the first report of invisible major salivary gland tumor on CT in the Korean literature.

• 대한두경부종양학회지
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• 제28권2호
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• pp.118-121
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• 2012

Backgrounds : To evaluated the use of FDG PET/CT for the identification of extracapsular spread(ECS) with histologic correlation in laryngeal cancer. Methods : We reviewed 79 medical records of patients who underwent of FDG PET/CT for laryngeal cancer before surgery. Results : ECS was present in 41.9%(18/43) dissected necks and in 34.5%(20/58) dissected cervical levels. There was a significant difference in the SUVmax between cervical lymph nodes with ECS and without ECS($6.39{\pm}4.53$ vs. $1.19{\pm}1.64$, p<0.001). The cut-off value for the SUVmax for differentiating with ECS from without ECS was 2.8 with the sensitivity of 85.7% and the specificity of 85.6%. Conclusion : The median SUVmax cut-off values of FDG PET/CT higher than 2.8 was associated with greater risk cervical lymph node metastasis with ECS in patients with laryngeal cancer.

• Radiation Oncology Journal
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• 제36권2호
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• pp.95-102
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• 2018

Purpose: To evaluate the prognostic value of $^{18}F$-fluorodeoxyglucose positron-emission tomography (FDG PET) with computed tomography (CT) before and during radiotherapy (RT) in patients with head and neck cancer. Methods: Twenty patients with primary head and neck squamous cell carcinoma were enrolled in this study, of whom 6 had oropharyngeal cancer, 10 had hypopharyngeal cancer, and 4 had laryngeal cancer. Fifteen patients received concurrent cisplatin and 2 received concurrent cetuximab chemotherapy. FDG PET/CT was performed before RT and in the 4th week of RT. The parameters of maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor were measured, and the prognostic significance of each was analyzed with the Cox proportional hazards model. Results: Higher TLG (>19.0) on FDG PET/CT during RT was a poor prognostic factor for overall survival (OS) (p = 0.001) and progression-free survival (PFS) (p = 0.007). In the multivariate analysis, TLG during RT as a continuous variable was significantly associated with OS and PFS rate (p = 0.023 and p = 0.016, respectively). Tumor response worse than partial remission at 1 month after RT was another independent prognostic factor for PFS (p = 0.024). Conclusions: Higher TLG of the primary tumor on FDG PET/CT during RT was a poor prognostic factor for OS and PFS in patients with head and neck cancer.

• 대한방사선치료학회지
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• 제31권2호
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• pp.13-24
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• 2019

목 적: 두경부 토모테라피 치료 시 다양한 이유로 CT scan range가 부족한 상황이 발생한다. CT scan range는 정확한 선량 계산에 영향을 주기 때문에 Re-CT Simulation이 좋지만 환자의 피폭선량 증가와 불편함, 치료일정 변경 등 문제점을 갖는다. 이에 본 저자는 기존 CT scan range에서 Plan setup parameter 변화를 통해 Re-CT Simulation 없이 정확한 치료계획에 필요한 최소한의 CT scan range를 평가해보고자 한다. 대상 및 방법: CT simulator(Discovery CT590 RT, GE, USA)와 In House Head & Neck Phantom을 이용하였고, Target의 끝단에서 0.25~3.0cm까지 0.25cm씩 증가시켜 CT scan range 별 이미지를 획득하였다. Target과 정상 장기를 Head & Neck Phantom에 등록하고 ACCURAY Precision^® 이용하여 치료계획을 설계하였다. 처방 선량은 Daily 2.2Gy, 27 Fxs, Total Dose 59.4Gy, Target은 처방 선량의 95~107%, 정상 장기는 SMC Protocol에 맞춰 치료계획을 설계하였다. 동일한 치료계획 조건에서 Field Width(FW)와 Jaw 모드를 고려한 5가지 방법(Fixed-1cm, Fixed-2.5cm, Fixed-5cm, Dynamic-2.5cm Dynamic-5cm)과 2가지 Pitch(0.43, 0.287)의 Plan Setup parameter로 치료계획을 설계하였다. 각 치료계획에 대한 선량 전달의 정확성은 EBT3 film과 RIT(Complete Version 6.7, RIT, USA)를 이용하여 분석하였다. 결 과: Target의 처방 선량과 정상 장기의 견딤선량(Tolerance dose)을 만족한 치료계획(SMC Protocol)은 Fixed-1cm은 0.25cm 이상, Fixed-2.5cm는 0.75cm 이상, Dynamic-2.5cm는 1cm 이상, Fixed-5cm과 Dynamic-5cm인 경우는 1.75cm 이상의 Scan range가 있어야 정확한 치료계획을 할 수 있었다. 선량 전달의 정확성은 RIT로 분석한 결과 SMC Protocol을 만족한 치료계획에서 3% 미만의 오차였다. 결 론: 두경부 토모테라피 치료 시 CT scan range가 부족한 경우 Plan Setup Parameter 중 Field Width(FW)를 조절하여 정확한 치료계획을 설계할 수 있었다. 이에 본 저자가 추천한 Plan Setup Parameter를 CT scan range에 따라 적용하고 Re-CT 여부를 판단한다면 업무의 효율성 및 환자의 피폭선량을 감소시킬 수 있을 것으로 사료된다.

• 대한두경부종양학회지
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• 제26권2호
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• pp.193-197
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• 2010

Objectives : Patients with neck tumor and their family need every information about the disease. Especially, the size and location are confusing with verbal information. With the aid of CT, the problem had some answer, but it needs some medical education. We would like to know the usefullness of 3D reconstructed images in patient education about the disease. Material and Methods : Neck CT data were collected from 10 patients with various neck tumors and converted to 3D reconstructed images. Understanding of the patients about the size and location of tumors were rated from questionaires using axial CT images and 3D images. Results : Understanding score about 3D images were greater than that of CT images(p<0.006). Conclusion : 3D reconstructed images of CT could give the patients more real visual information about the disease.