• Radiation Oncology Journal
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• v.14 no.2
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• pp.115-122
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• 1996

Purpose : To improve the treatment results of locally advanced nonsmall cell lung cancer (NSCLC) patients we treated those patients with regional hyperthermia combined with radiotherapy. And we conducted a retrospective analysis of the results. Material and Methods Thirty two nonsmall cell lung cancer Patients treated at the Department of Radiation Oncology, St. Mary's hospital, Catholic University Medical College were the base of this analysis. Fourteen patients of above them were treated with hyperthermia and radiotherapy of more than 3000 cGy in radiation dose. Radiofrequency capacitive hyperthermia was administered twice weekly immediately after radiotherapy. Total sessions of hyperthermia ranged from 3 to 13 times (mean 7.8). Eighteen patient received an external radiation therapy alone Median radiation dose was 5580 cGy (range, 3000-7000 cGy) in fraction of 180-300 cGy, 5 fractions per week. Results: The results of themoradiotherapy group (HTRT group) were compared with radiation alone group (RT group). There were no complete response (CR) and 12 Partial responses (PR) (CR rate $0\%$, response rate $85.7\%$) in HTRT group, whereas there were 2 CRs, 8 PRs and 8 no responses (CR rate $11.1\%$, response rate $55.6\%$) in RT group. There was significant differece in local response rate of the tumors between RT group and HTRT group (p < 0.05). Overall 2 rear survival rate and mean survival were $7.1\%$ and 10.5 months for HTRT group, and $0\%$ and 8.1 months for RT group. However, by the number of hyperthermia. in cases with more than or equal to 10 sessions of hyperthermia, there were significant improvement in 2 year year survival rate and mean survival ($40.0\%$ and 18.2 months) compared with those in cases with less than 10 sessions of hyperhtemia ($7.4\%$ and 7.4 months) (p < 0.05). Conclusion : Thermoradiotherapy in locally advanced NSCLC patients increased their response rate but not 2 year survival and mean survival, therefore thermoradiotherpy with enough number of hyperthermia is suggested that may be one of the effective palliative treatments of those patients. And in cases with more than 10 sessions of hyperthermia, there showed improved 2 year survival rate and mean survival But the number of the cases was small further study in this aspect is required.

• Progress in Medical Physics
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• v.26 no.3
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• pp.127-136
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• 2015

The purpose of this study is to perform a dosimetric evaluation of amplitude-based respiratory gating for the delivery of volumetric modulated arc therapy (VMAT). We selected two types of breathing patterns, subjectively among patients with respiratory-gated treatment log files. For patients that showed consistent breathing patterns (CBP) relative to the 4D CT respiration patterns, the variability of the breath-holding position during treatment was observed within the thresholds. However, patients with inconsistent breathing patterns (IBP) show differences relative to those with CBP. The relative isodose distribution was evaluated using an EBT3 film by comparing gated delivery to static delivery, and an absolute dose measurement was performed with a $0.6cm^3$ Farmer-type ion chamber. The passing rate percentages under the 3%/3 mm gamma analysis for Patients 1, 2 and 3 were respectively 93.18%, 91.16%, and 95.46% for CBP, and 66.77%, 48.79%, and 40.36% for IBP. Under the more stringent criteria of 2%/2 mm, passing rates for Patients 1, 2 and 3 were respectively 73.05%, 67.14%, and 86.85% for CBP, and 46.53%, 32.73%, and 36.51% for IBP. The ion chamber measurements were within 3.5%, on average, of those calculated by the TPS and within 2.0%, on average, when compared to the static-point dose measurements for all cases of CBP. Inconsistent breathing patterns between 4D CT simulation and treatment may cause considerable dosimetric differences. Therefore, patient training is important to maintain consistent breathing amplitude during CT scan acquisition and treatment delivery.

• Tuberculosis and Respiratory Diseases
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• v.51 no.1
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• pp.25-34
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• 2001

Background : Inhaled glucocorticoids are the medical treatment of choice in asthma patients. Fluticasone propionate is one of the most effective inhaled corticosteroids and has been reported to have minimal effect on the hypothalamic-pituitary-adrenal axis at the recommended dose. However, reports of long-term trials characterizing their systemic safety with chronic use are rare. This study was designed to evaluate the long-term safety of inhaled fluticasone propionate to the hypothalamic-pituitary-adrenal axis. Method : This study was conducted on 21 patients to evaluate the adrenal response to rapid ACTH stimulation test after 6 months of treatment with fluticasone propionate from $200\;{\mu}g$ to $750\;{\mu}g$ daily. The serum cortisol levels was measured to assess its effect on the hypothalamic-pituitary-adrenal axis just prior to the injection, at 30 minutes and 60 minutes after an intramuscular injection of synthetic ACTH. Result : The mean dose of inhaled fluticasone propionate was $355\;{\mu}g$ per day(SD=$174\;{\mu}g$, range=$200\;{\mu}g$ to $750\;{\mu}g$). The mean serum cortisol levels of the patients was $11.0\;{\mu}g/d{\ell}$(SD=$6.4\;{\mu}g/d{\ell}$) prior to the injection, $20.0\;{\mu}g/d{\ell}$ (SD=$7.7\;{\mu}g/d{\ell}$) after 30 minutes, and $23.0\;{\mu}g/d{\ell}$(SD=$6.3\;{\mu}g/d{\ell}$) after 60 minutes. Sixteen patients of the 21 patients had a normal response(> $18\;{\mu}g/d{\ell}$), and 5 out of the 21 patients had serum cortisol levels below the normal range after the rapid ACTH stimulation test. Conclusion: Adrenal suppression occurred in 5 out of 21 patients with 6 months treatment with inhaled fluticasone propionate.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.78-82
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• 2010

Purpose: Recently, South Korea has seen a rapidly increased incidence of both breast and thyroid cancers. As a result, the I-131 scan and lymphoscintigraphy have been performed more frequently. Although this type of diagnostic imaging is prominent in that visualizes pathological conditions, which is similar to previous nuclear diagnostic imaging techniques, there is not much anatomical information obtained. Accordingly, it has been used in different ways to help find anatomical locations by transmission scan, however the results were unsatisfactory. Therefore, this study aims to realize an imaging technique which shows more anatomical information through the fusion of gamma and realistic imaging. Materials and Methods: We analyzed the data from patients who were examined by the lymphoscintigraphy and I-131 additional scan by Symbia Gamma camera (SIEMENS) in the nuclear medicine department of the National Cancer Center from April to July of 2009. First, we scanned the same location in patients by using a miniature camera (R-2000) in hyVISION. Afterwards, we scanned by gamma camera. The data we obtained was evaluated based on the scanning that measures an agreement of gamma and realistic imaging by the Gamma Ray Tool fusion program. Results: The amount of radiation technicians and patients were exposed was generated during the production process of flood source and applied transmission scan. During this time, the radiation exposure dose of technicians was an average of 14.1743 ${\mu}Sv$, while the radiation exposure dose of patients averaged 0.9037 ${\mu}Sv$. We also confirmed this to matching gamma and realistic markers in fusion imaging. Conclusion: Therefore, we found that we could provide imaging with more anatomical information to clinical doctors by fusion of system of gamma and realistic imaging. This has allowed us to perform an easier method in which to reduce the work process. In addition, we found that the radiation exposure can be reduced from the flood source. Eventually, we hope that this will be applicable in other nuclear medicine studies. Therefore, in order to respect the privacy of patients, this procedure will be performed only after the patient has agreed to the procedure after being given a detailed explanation about the process itself and its advantages.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.671-677
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• 2017

In this study, scattering factors affecting the quality of medical images were quantitatively analyzed and investigated. MCNPX simulation was conducted by using ANSI phantom, made of tissue equivalent materials, to calculate the scattering ratio occurred by the increase of the object thickness. Then, the result of the simulation was compared with the result of actual radiation measurement. In addition, we evaluated the image quality by the RMS evaluation, RSD and NPS analysis using X-ray images acquired with increasing object thickness. Furthermore, the scattering ratio was analyzed by increasing the thickness of acrylic phantom on chest phantom. The result showed that the scattering ratio was increased to 57.2%, 62.4%, and 66.8% from 48.9%, respectively, when the acrylic phantom thickness was increased by 1 inch from 6.1 inches. The results of MCNPX simulation and the actual measured scattering dose showed similar results. Also, as a result of RMS measurement from acquired x-ray images, the standard deviation decreased as the object thickness increased. However, in the RSD analysis considering the average incident dose, the results were increased from 0.028 to 0.039, 0.051, 0.062 as the acrylic phantom thickness was increased from 6.1 inches to 7.1 inch, 8.1 inch, and 9.1 inch, respectively. It can be seen that the increase of the scattering effect due to the increase of the object thickness reduces the SNR. Also, the NPS results obtained by measuring scattered radiation incident on the detector resulted in the increase of the noise as the object thickness increased.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.225-231
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• 1997

Purpose : Radiation therapy in combination with surgery has an important role in the therapy of the head and neck cancer We conducted a prospective study for patients with head and neck cancer treated with surgery and radiation to evaluate the effect of therapies on the thyroid gland, and to identify the factors that might influence the development of hypothyroidism. Materials and Methods : From September 1986 through December 1994, 71 patients with head and cancer treated with surgery and radiation were included in this prospective study. Patients' age ranged from 32 to 73 years with a median age of 58 years. There were 12 women and 59 men. The primary tumor sites were larynx in 34 patients, hypopharynx in 13 patients, oral cavity in 12 patients, unknown primary of the neck in 6 patients, salivary gland in 3 patients, maxillary sinus in 2 patients, and oropharynx in 1 patient. Total laryngectomy with neck dissection was carried out in 45 patients and neck dissection alone in 26 patients. All patients were serially monitored for thyroid function (T3, T4, free T4, TSH, antithyroglobulin antibody and antimicrosomal antibody) before and after radiation therapy. Radiation dose to the thyroid gland ranged from 40.6Gy to 60Gy with a median dose of 50Gy The follow-up duration was 3 to 80 months. Results :The overall incidence of hypothyroidism was 56.3\%$);7 out of 71 patients $(9.9\%)$ developed clinical hypothyroidism and 33 patients $(46.4\%)$ developed subclinical hypothyroidism. No thyroid nodules, thyroid cancers, or hyperthyroidism was detected. Hypothyroidism developed earlier in patients who underwent total laryngectomy with neck dissection than in patients with neck dissection alone (P<0.05). The risk factor that significantly influenced the incidence of hypothyroidism was a combination of surgery (total laryngectomy with neck dissection) and radiation therapy (P=0.0000), Four of 26 patients $(15.4\%)$ with neck dissection alone developed hypothyroidism while 36 of 45 patients $(80\%)$ with laryngectomy and neck dissection developed hypothyroidism. Conclusion : The hypothyroidism following surgery and radiation therapy was a relatively common complication. The factor that significantly influenced theincidence of hypothyroidism was combination of surgery and radiation therapy. Evaluation of thyroid function before and after radiation therapy with periodic thyroid function tests is recommended for an early detection of hypothyroidism and thyroid hormone replacement therapy is recommended whenever hypothyroidism develops.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.177-183
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• 2010

Purpose: Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Materials and Methods: Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inframammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. Results: The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. Conclusion: The use of 3D CT based planning reduced the radiation field in early breast cancer patients with small breasts in relation to conventional planning. Though a coherent definition of the breast is needed, CT-based planning generated the better plan in terms of reducing the irradiation volume of normal tissue. Moreover it was possible that 3D CT based planning showed better CTV coverage including postoperative change.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.1-9
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• 2001

Purpose : To establish the role of stereotactic radiosurgery (SRS) for the treatment of patients with angiographically occult vascular malformation (AOVM). Materials and Methods : Eleven patients (12 lesions) with AOVM were treated with linear accelerator-based SRS between February 1995 and December 1999. A magnetic resonance imaging of each patients showed well-circumscribed vascular lesion with reticulated core of heterogeneous signal intensity and peripheral rim of low signal intensity. SRS were peformed with the median peripheral dose of 16 Gy (range 13~25). A single isocenter was used with median collimator size of 14 mm (range 8~20) diameter. Results : With a median follow-up period of 42 months (range 12~56), rebleeding occurred in 3 AOVMS at 5, 6 and 12 months after SRS but no further bleeding did. Two patients experienced radiation-induced necrosis associated with permanent neurologic deficit and one patient showed transient edema of increased 72 signal intensity. Conclusion : SRS may be effective for the prevention of rebleeding in AOVM located in surgically inaccessible region of the brain. Careful consideration should be needed in the decision of case selection and dose prescription because the incidence of radiation-induced complications is too high to be accepted.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.59-66
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• 1994

Seventy-five patients with tumors of the head and neck treated with either radiation therapy alone or combined with surgery or chemotherapy were studied prospectively to evaluate the effects of radiation therapy to the neck on thyroid gland between September 1986 and October 1992. All patients were serially monitored for thyroid function tests before and after radiation therapy. Radiation dose to the thyroid gland ranged from 35 to 60 Gy with a median dose of 50 Gy. Median follow-up time was 30 months with a range of 11 to 85 months. The incidence of thyroid dysfunction was 40$ \% $: forty-five patients(60$ \% $) euthyroid, 2 patients(3$ \% $) clinical hypothyroidism, 27 patients(36$ \% $) subclinical hypothyroidism and 1 patient(1$ \% $) hyperthyroidism. No thyroid nodules or thyroid cancer were detected in any patients. Thyroid dysfunction appeared earlier in patients who underwent surgery than in those patients treated with radiation therapy alone or combination of chemotherapy and radiation therapy(P=0.0013). By multivariate analysis, risk factors that significantly influenced a higher incidence of thyroid dysfunction were female sex(p=0.0293) and combination of total laryngectomy and radiation therapy(p : 0.0045). In conclusion, evaluation of thyroid function before and after radiation therapy with periodic thyroid function tests are recommended to detect thyroid dysfunction in time and thyroid hormone replacement therapy is recommended whenever thyroid dysfunction develops.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.129-135
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• 1999

Purpose : This study evaluated early bowel complications in cervix cancer patients, following external radiotherapy (ERT and high dose rate intracavitary radiation (HDR ICR). Factors affecting the risk of developing early bowel complications and its incidence are analyzed and discussed Materials and Methods : The study is the retrospective review of 66 patients who received radiotherapy at Chungbuk National University Hospital from April 1994 to December 1998. The patients underwent 41.4 or 50.4 Gy ERT according to FIGO stage and tumor size, then A point dose was boosted to 71.4 or 74.4 Gy using a remotely controlled afterloading Buchler HDR ICR. The EORTC/RTOG morbidity criteria were used to grade early bowel complications, which are valid from day 1, the commencement of therapy, through day 90. The actuarial incidence, severity of complications were investigated and clinical pretreatment factors relevant to complications were found through univariate (Wilcoxon) and multivariate (Cox proportional hazard model) analysis. Results : Of the 66 patients, 30 patients (46$\%$) developed early bowel complications; 25 patients (38$\%$) with grade 1 or 2, 4 patients (0$\%$) with grade 3 and 1 patient (2$\%$) with grade 4. The complications usually began to occur 3 weeks after the commencement of radiotherapy. The actuarial incidence of early bowel complications was 41$\%$ at 10 weeks. The early bowel complications were associated significantly with an old age and a history of previous abdomino-pelvic surgery. All three patients who had a protracted overall treatment time (about 2 weeks) due to severe bowel complication, suffered from pelvic recurrences. Conclusion : Forty six percent of patients experienced early bowel complications, most of which were grade 1 or 2 and relieved spontaneously or by medication. The patients with an old age or a previous surgery have a high probability of early complications and they may be less compliant with planned radiotherapy. So more careful precaution is necessary for these patients.