• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2003.09a
• /
• pp.52-52
• /
• 2003

악성종양을 치료하는 방법중 방사선과 온열요법은 가장 강력한 치료방법으로 연구되어왔으며 이를 병용함으로 서 상승효과를 얻을 수 있다. 인체조직에 41$^{\circ}C$ 이상의 열을 가하면 세포질의 단백질변성으로 세포에 손상을 주어 세포가 사멸하게 되며 세포의 생존율은 가열시간 즉 열량에 따라 지수적으로 감소한다. 온열은 세포주기중 방사선 저항성이 매우 큰 DNA 합성시기와 산도가 높을 때 감수성이 매우 크기 때문에 방사선과 병용요법은 상호 상승효과를 가져온다. 이와 같이 온열을 이용한 악성종양의 치료가능성은 생물학적 기초연구와 임상시험에서 경이적인 효과를 얻을 수 있었으나 아직 까지 가열방법과 온도분포측정이 큰 과제로 남아있으며 주위건강조직의 가열을 피하면서 인체 깊은 곳에 존재하는 종양에만 집중 가열하는 방법인 삽입형 온열치료방법에 대한 연구가 집중되었다. 한편 방사선 치료방법은 주위 건강조직의 피폭을 최소로 줄이고 종양에만 집중 조사가 요구되며 자궁암, 유방암, 뇌암등 부피가 작고 집중적 치료를 요하는 종양은 방사성동위원소를 이용한 근접 삽입치료 (Brachyradiotherapy)가 큰 효과를 나타내고 있다 방사선과 온열의 병행 치료를 위하여 방사선 삽입 치료에 사용한 선원 삽입관을 그대로 두고 삽입관 속에 방사성 동위원소 대신 온열 전극을 넣어 열을 가하는 방사선 온열 병용치료방법을 고안하였으며 방사선과 온열병용에 사용할 최적 삽입관의 제작과 이에 따른 온도분포의 측정과 최적삽입방법을 결정하였다. 방사선 삽입치료용 폴리에찌렌 삽입관의 외부에 금박을 입혀 라디오파 첨극을 삽입할 때 서로 연결되도록 고안 제작함으로서 방사선 삽입치료와 자입식 온열치료를 동시에 만족하게 수행할 수 있는 병용삽입관 (Flexible thermoradiotherapy probes)을 제작하였다. 전도율이 큰 금박부위가 직접 조직에 접촉됨으로 라디오파의 전달이 용이하며 금박의 길이를 2 cm 에서 5 cm 로 구분제작 함으로서 종양의 크기와 모양에 따라 선택할 수 있도록 하였다. 라디오파를 이용한 온열분포의 측정은 인체조직과 전기적 특성이 비슷한 물질인 한천 팬텀 제작하여 사용하였으며 온도분포 측정은 열전대와 서머그람으로 시행하였다. 생체조직 내에서의 온도분포와 온열효과를 관찰하기 위하여 직접 개의 뇌를 이용하여 시행하였으며 4 개의 전극을 이용하여 43$^{\circ}C$로 50분간 가열하고 일주일후 개를 회생시켜 개 뇌에 대한 조직학적 검사를 시행하였다. 한편 팬텀 표면에서 중앙부로 안테나 길이가 2 cm 인 4 개의 전극을 1 cm 간격으로 정사각형이 되도록 삽입하여 가열하였을 때 90% 등온곡선이 반경 1.25의 원형으로 균일하게 분포되었고 종단면상 삽입관의 길이에 따라 균일한 온도분포가 이루어졌다. 전극을 2 cm 간격으로 삽일 하였을 때 90% 등온곡선이 1.75 반경으로 거의 4 각형의 균일한 분포를 얻었으나 전극의 간격이 증가하면 전도율이 떨어져서 전극 중심부에 불균일한 온도분포를 형성하였다. 동물실험에서 정상 개의 뇌 실질에 자입하여 직접 정방형의 중심을 43$^{\circ}C$로 유지하며 50분간 온열 요법을 시행한 후 관찰한 조직병리학적 소견은 liquefactive necrosis, pyknosis of neuronal element 및 polymorphonuclear leukocytes들의 회백질에서 급성기에 관찰되었고 liquefactive necrosis 주위에 lipid-laden macrophage들이 관찰됨이 공통적인 특정이었으며 후기변화로 괴사조직 주위로 신경교세포의 증식이 관찰되었다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.1
• /
• pp.56-62
• /
• 2009

In this paper we investigate an analytical approach for noise properties and geometric structure in Computed Radiography(CR) images of industrial steel-tubes. Over thirty diverse radiographic images are sampled from industrial radiography measurements according to radiation intensity. Each image consists of three regions; background, thickness and inner-tube. Among these the region of inner-tube is selected for the object of analysis. Geometric structure which includes the noise generation is analyzed by the statistical and functional methodology. The analysis is carried on spacially and line by line. It verifies the geometrical transfigure from the circle configuration of steel-tube and noise variation. The estimation of fitting function and its error are the geometric factors. The statistics such as standard deviation, mean and signal-to-noise ratio are noise parameters for discrimination. These factors are considered under the intensity variation which is the penetrative strength of radiation. The analysing results show that the original geometry of circle is preserved in the form of elliptic or short/long diameter circle, and the noise deviation has increased inverse proportional to the radiation intensity.

• Radiation Oncology Journal
• /
• v.10 no.1
• /
• pp.35-41
• /
• 1992

Forty eight patients with adenoid cystic carcinoma (ACC) in the head and neck treated between 1979 and 1990 were reviewed according to treatment modalities and clinical courses. The common site of origin was minor salivary gland ($69\%$), mostly hard palate and maxillary sinus. 11 patients received radiation therapy (RT) alone and 37 patients received combined surgery and radiation therapy. The follow-up period of the survivors ranged from 4 to 118 months (median 49.5 months). The 5 year local control rate was $69.3\%$, $67.3\%$ and 83.9$\%$ in RT alone, conservative operation (OP)+RT and radical OP+RT group, respectively (p>0.05). The control of local disease was best achieved with radical OP+RT. In postoperative RT, high dose ($\ge$60 Gy) and generous field size($\ge$64 cm$^2$) yielded a better local control rate. Actuarial overall survival rate was $79.0\%$, at 5 years and $19.2\%$ at 10 years. Distant metastases (DM) developed in $40\%$ of patients, mostly in the lung. Disease-free (NED) survival rate was $45.8\%$ at 5 years and significant differences did not exist according to primary sites and treatment options. Survival rate after the onset of DM was $19.5\%$ at 5 years. Occurrence of DM tends to lower survival significantly. In an effort to find the role of RT in the treatment of ACC, our data suggest that a well-planned postoperative RT employing a high dose and generous field size can produce high local control rate and remaining urgent problem of distant metastasis demands more effective chemotherapy for the purpose of improving survival of ACC patients.

• Radiation Oncology Journal
• /
• v.11 no.2
• /
• pp.233-240
• /
• 1993

Chromosomal aberration analysis, as a basis for biological radiation dosimetry, was performed for radiation dose ranges below 150 cGy. The yield, ratio of lymphocytes with dicentric and/or ring chromosomes, was 0, 0, 0.4, 0.5, 0.6, 0.8, 1.8, 5.5, 8.0, and $18.5\%$ for 0,5, 10, 15, 20, 25, 50, 75, 100 and 150 cGy, respectively. The Qdr, ratio of dicentric and ring chromosomes in total lymphocytes, was 0, 0, 0.004, 0.005, 0.006, 0.009, 0.018, 0.055, 0.084 and 0.207, respectively. The Qdr, ratio of dicentric and ring chromosomes in lymphocytes with aberration, was 1.0 for the radiation doses up to 75 cGy and 1.05 and 1.11 for 100 and 150 cGy, respectively. From the results, it seems possible to estimate radiation dose from Ydr when the exposure is 25 cGy or more. All the 5 radiation workers studied, with exposure much less than 1 mSv per month, had chromosomal aberrations. And acentric fragment pairs, in addition to dicentric and ring chromosomes, showed good dose response relationship and so may be useful for biological dosimetry for low dose radiation.

• Radiation Oncology Journal
• /
• v.16 no.1
• /
• pp.51-61
• /
• 1998

Purpose : Treatment of choice for uterine cervix cancer stage IIB is radiotherapy. We analyzed survivals, Prognostic factors, patterns of failure and complications. Materials and Methods : This is a retrospective analysis of 167 patients with stage IIB carcinoma of uterine cervix treated with curative external pelvic and high dose rate intracavitary radiotherapy at the Department of Therapeutic Radiology, Soonchunhyang University Hospital from August 1985 to August 1994. All the patients followed up from 3 to 141 months(mean 60 months) and age of patients ranged from 31 to 78 years at presentation(mean : 55 years). Results : Overall complete response rate was $84\%$. The response rate for squamous cell carcimoma and adenocarcinoma were $86\%$ and $60\%$, respectively. Overall 5-years survival rate and disease free survival rate was 62 and $59\%$, respectively Mass size and treatment response were significant Prognostic factors for survival Pathologic type and parametrial involvement were marginally significants Prognostic factors. Local failure was 43 cases, distant metastasis was 14 cases and local failure plus distant metastasis was 3 cases, and most of local failures occurred within 24 months, distant metastasis within 12 months after treatment Twenty eight($16.8\%$) patients developed late rectal and urinary complications There were tendency to increasing severity and frequency according to increased fractional dose and total(rectal and bladder) dose. Conclusions : Survival rate was significantly related to tumor size and radiotherapy response. Tumor size should be considered in the clinical s1aging. To increased survival and local control, clinical trials such as decreasing duration of radiotherapy or addition of chemotherapy is needed. To detect early recurrence, regular follow up after RT is important. Because total rectal and bladder dose affected late complications. meticulous vaginal packing is needed to optimize dose of normal tissues and to decrease late complications.

• Journal of Radiation Protection and Research
• /
• v.24 no.1
• /
• pp.45-53
• /
• 1999

Fluorescence in situ hybridization with chromosome-specific probe has been shown to be a valid and rapid method for detection of chromosome rearrangements induced by radiation. This method is useful for quantifying structural aberrations, expecially for stable ones, such as translocation and insertion, which are difficult to detect with conventional method in human lymphocyte. In order to apply FISH method for high dose biological dosimetry, chromosomal abberations by radiation at doses of 1, 3, 5, and 7Gy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. The frequencies of stable translocation per cell equivalent were 0.04, 0.33, 1.22, 2.62, and 5.58 for the lymphocyte exposed to 0, 1, 3, 5, and 7Gy, respectively, and those of dicentric were 0.00, 0.06, 0.52, 1.19 and 2.44, respectively. Significantly more translocation of t(Ab), a translocated chromosome with a piece of painted acentric matrial 'b' attached to unpainted piece containing centromere 'A', than reciprocal chromosome t(Ba) was observed. The frequencies of all type of chromosome rearrangements increased with dose. From above result, FISH seemed to be useful for radiation biodosimetry by which the frequencies of various types of stable aberrations in human lymphocyte can be observed more easily than by conventional method and so will improve our ability to perform meaningful biodosimetry.

• The korean journal of orthodontics
• /
• v.37 no.6
• /
• pp.391-399
• /
• 2007

Three-dimensional approaches for the diagnosis and analysis of the dentofacial area are becoming more popular in accordance with the development of cone-beam CT (CBCT). The purposes of this study were to evaluate the reliability of cephalometric measurements of lateral cephalograms generated from a CBCT image by making comparisons with the traditional digital lateral cephalogram, and to evaluate the possibility of the clinical application of CBCT generated cephalogram images. Methods: Twenty patients whose external auditory meatus could be identified in the CBCT image were selected, and both CBCT and digital cephalograms were taken. Differences between the measurements of both cephalograms were tested by paired t-test. Results: Among the 22 measurements used, only U1-FH, Mx6 to PTV, and maxillomandibular difference showed statistically significant differences between the CBCT generated cephalogram and the digital cephalogram. Conclusions: The results suggest that the CBCT generated cephalogram can be used for some cephalometric measurements not requiring porion, PTV, condylion as a landmark (SNA, SNB, U1 to SN, IMPA, interincisal angle, etc.).

• Radiation Oncology Journal
• /
• v.20 no.2
• /
• pp.130-138
• /
• 2002

Purpose : This study analyzed the prognostic factors affecting the survival rate and evaluated the role of radiation therapy in muscle-invading bladder cancer. Materials and Methods : Twenty eight patients with bladder cancer who completed planned definitive radiotherapy in the Departments of Therapeutic Radiology and Urology, Chonnam National University Hospital between Jan. 1986 to Dec. 1998 were retrospectively analyzed. The reviews were peformed based on the patients' medical records. There were 21 males and 7 females in this study. The median of age was 72 years old ranging from 49 to 84 years. All patients were confirmed as having transitional cell carcinoma with histological grade 1 in one patient, grade 2 in 15, grade 3 in 9, and uninformed in 3. Radiation therapy was peformed using a linear accelerator with 6 or 10 MV X-rays. Radiation was delivered daily with a 1.8 or 2.0 Gy fraction size by 4 ports (anterior-posterior, both lateral, alternatively) or 3 ports (Anterior and both lateral). The median radiation dose delivered to the isocenter of the target volume was 61.24 Gy ranging from 59 to 66.6 Gy. The survival rate was calculated by the Kaplan-Meier method. Multivariate analysis was peformed on the prognostic factors affecting the survival rate. Results : The survival rate was $76\%,\;46\%,\;33\%,\;33\%$ at 1, 2, 3, 5 years, respectively, with 19 months of median survival. The potential factors of age (less than 70 years vs above 70), sex, diabetes mellitus, hypertension, hydronephrosis, 1-stage (T3a vs T3b), TUR, chemotherapy, total duration of radiotherapy, radiation dose (less than 60 Gy vs above 60 Gy), and the treatment response were investigated with uniand multivariate analysis. Un univariate analysis, the T-stage (p=0.078) and radiation dose (p=0.051) were marginally significant, and the treatment response (p=0.011) was a statistically significant factor on the survival rate. Multivariate analysis showed there were no significant prognostic factors affecting the survival rate. Conclusion : The treatment response and radiation dose are suggested as th은 statistically significant factors affecting the survival rate of muscle invasive bladder cancer. A Further prospective randomized study is needed to confirm these prognostic factors.

• Journal of radiological science and technology
• /
• v.27 no.3
• /
• pp.19-24
• /
• 2004

MRI imaging is one of the imaging techniques showing anatomical structures of human body for medical diagnosis, and has been researched in order to provide better quality of anatomical information. In this study, we propose a very useful method to extract an interest areas and how to diagnose necrolysis of femoral neck disease automatically. Regions of femoral neck is set using anatomical features and Hough transform and advantages of both region extension and histogram-based region segmentation method are combined for better region segmentation. As a result of the proposed method, good imaging quality was obtained for femoral neck with both normal and severe necrosis as well as for femoral neck in early stage of necrolysis.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.23 no.2
• /
• pp.373-378
• /
• 1993

Although osteochondroma is not rare in the axial skeleton and long bones, it is very rare in the jaw. It is a benign chondroma within which partial endochondral ossification occurs. There are two types, the central one and the peripheral one. Peripheral type is more common than central one in the jaw, but it is not frequent. Especially it is rare at the mandibular condyle. When it occurred at the mandibular condyle, it is generally located at the lateral portion of the condyle. In that case, facial asymmetry with occlusal change is the characteristic clinical feature. But it is similar to condylar hyperplasia so that misdiagnosis can sometimes occur. The differential point is as follows: Hyperplasia generally appears as a generalized enlargement of the condylar process with a normal cortical thickness, but osteochondroma usually appears as a focal growth or mass. We report a very rare case of peripheral osteochondroma at the mandibular condyle in a 27-year- old male patient who visited DKUDH with a chief complaint of the facial asymmetry.