• Progress in Medical Physics
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• v.17 no.4
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• pp.207-211
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• 2006

The advent of kV cone-beam computed tomography (CBCT) integrated with a linear accelerator allows for more accurate Image-guided radiotherapy (IGRT). IGRT is the technique that corrects target displacement based on internal body information. To do this, the CBCT Image set is acquired just before the beam is delivered and registered with the simulation CT Image set. In this study, we compare the registration results according to the CBCT's reconstruction quality (either high or medium). A total of 56 CBCT projection data from 6 patients were analyzed. The translation vector differences were within 1 mm in all but 3 cases. For rotation displacement difference, components of all three axes were considered and 3 out of 168 ($56{\times}3$ axes) cases showed more than lo of rotation differences.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1435-1442
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• 2015

Purpose: To study the patient load, treatment pattern, survival outcome and its predictors in patients with brain metastases treated by radiotherapy. Materials and Methods: Data for patients with brain metastases treated by radiotherapy between 2003 and 2007 were collected from medical records, the hospital information system database, and a population-based tumor registry database until death or at least 5 years after treatment and retrospectively reviewed. Results: The number of treatments for brain metastases gradually increased from 48 in 2003 to 107 in 2007, with more than 70% from lung and breast cancers. The majority were treated with whole brain radiation of 30 Gy (3 Gy X 10 fractions) by cobalt-60 machine, using radiation alone. The overall median survival of the 418 patients was 3.9 months. Cohort analysis of relative survival after radiotherapy was as follows: 52% at 3 months, 18% at 1 year and 3% at 5 years in males; and 66% at 3 months, 26% at 1 year and 7% at 5 years in females. Multivariate analysis demonstrated that the patients treated with combined modalities had a better prognosis. Poor prognostic factors included primary cancer from the lung or gastrointestinal tract, emergency or urgent consultation, poor performance status (ECOG 3-4), and a hemoglobin level before treatment of less than 10 g/dl. Conclusions: This study identified an increasing trend of patient load with brain metastases. Possible over-treatment and under-treatment were demonstrated with a wide range of survival results. Practical prognostic scoring systems to assist in decision-making for optimal treatment of different patient groups is absolutely necessary; it is a key strategy for balancing good quality of care and patient load.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.19-25
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• 2017

In this study, in order to analyze the general awareness of the nuclear power according to the controversy of thyroid cancer around nuclear plant, we investigated risks, preference and economics regarding type of power, and awareness of pre-post nucl ear power targeting the Busan Metropolitan residents. As a result, there has been a change in people's awareness of nuclear power as a result of the controversy thyroid cancer around nuclear plant. Especially, there was the greatest increase in the risk factors compared to before the event(p<0.05). Negative awareness of nuclear risk was shown to be expressed differently accor ding to the difference between groups. It is thought that this is due to the different prior experience of each individuals or obtained information through the interaction with others rather than on scientific and objective grounds. In order to establish a nuclear power policy considering the level of the people in the future, it seems that the efforts to understand the attitudes and opinions of people about nuclear power and above all, a scientific trust in nuclear power should be guaranteed.

• Progress in Medical Physics
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• v.33 no.4
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• pp.114-120
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• 2022

Purpose: Particle beam therapy is advantageous over photon therapy. However, adequately delivering therapeutic doses to tumors near critical organs is difficult. Nanoparticle-aided radiation therapy can be used to alleviate this problem, wherein nanoparticles can passively accumulate at higher concentrations in the tumor tissue compared to the surrounding normal tissue. In this study, we investigate the dose enhancement effect due to gold nanoparticle (GNP) when Carbon-12, He-4, and proton beams are irradiated on GNP. Methods: First, monoenergetic Carbon-12 and He-4 ion beams of energy of 283.33 MeV/u and 150 MeV/u, respectively, and a proton beam of energy of 150 MeV were irradiated on a water phantom of dimensions 30 cm×30 cm×30 cm. Subsequently, the secondary-particle information generated near the Bragg peak was recorded in a phase-space (phsp) file. Second, the obtained phsp file was scaled down to a nanometer scale to irradiate GNP of diameter 50 nm located at the center of a 4 ㎛×4 ㎛×4 ㎛ water phantom. The dose enhancement ratio (DER) was calculated in intervals of 1 nm from the GNP surface. Results: The DER of GNP computed at 1 nm from the GNP surface was 4.70, 4.86, and 4.89 for Carbon-12, He-4, and proton beams, respectively; the DER decreased rapidly with increasing distance from the GNP surface. Conclusions: The results indicated that GNP can be used as radiosensitizers in particle beam therapy. Furthermore, the dose enhancement effect of the GNP absorbed by tumor cells can aid in delivering higher therapeutic doses.

• Journal of the Korean Society of Radiology
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• v.3 no.3
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• pp.5-11
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• 2009

When using Image Guided Radiation Therapy, the patient is placed using skin marker first and after confirming anatomical location using OBI, the couch is moved to correct the set up. Evaluation for the error made at that moment was done. Through comparing $0^{\circ}$ and $270^{\circ}$ direction DRR image and OBI image with 2D-2D matching when therapy planning, comparison between patient's therapy plan setup and actual treatment setup was made to observe the error. Treatment confirmation on important organs such as head, neck and spinal cord was done every time through OBI setup and other organs such as chest, abdomen and pelvis was done 2 ~ 3 times a week. But corrections were all recorded on OIS so that evaluation on accuracy could be made through using skin index which was divided into head, neck, chest and abdomen-pelvis on 160 patients. Average setup error for head and neck patient on each AP, SI, RL direction was $0.2{\pm}0.2cm$, $-0.1{\pm}0.1cm$, $-0.2{\pm}0.0cm$, chest patient was $-0.5{\pm}0.1cm$, $0.3{\pm}0.3cm$, $0.4{\pm}0.2cm$, and abdomen was $0.4{\pm}0.4cm$, $-0.5{\pm}0.1cm$, $-0.4{\pm}0.1cm$. In case of pelvis, it was $0.5{\pm}0.3cm$, $0.8{\pm}0.4cm$, $-0.3{\pm}0.2cm$. In rigid body parts such as head and neck showed lesser setup error compared to chest and abdomen. Error was greater on chest in horizontal axis and in AP direction, abdomen-pelvis showed greater error. Error was greater on chest in horizontal axis because of the curve in patient's body when the setup is made. Error was greater on abdomen in AP direction because of the change in front and back location due to breathing of patient. There was no systematic error on patient setup system. Since OBI confirms the anatomical location, when focus is located on the skin, it is more precise to use skin marker to setup. When compared with 3D-3D conformation, although 2D-2D conformation can't find out the rolling error, it has lesser radiation exposure and shorter setup confirmation time. Therefore, on actual clinic, 2D-2D conformation is more appropriate.

• Progress in Medical Physics
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• v.16 no.4
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• pp.183-191
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• 2005

The utilization of PET has been increased so fast since the usefulness of the PET has been proved in various clinical and research fields. Among the many applications, the PET Is especially useful in oncology and most of the clinical PET scans are peformed for the oncologic examination Including the different diagnosis of malignant and benign tumors and assessment of the treatment effects and recurrent tumors. As the PET-CT scanners are widely available, there is Increasing interest in the application of the PET Images to the radiation treatment planning. Although the CT images are conventionally used for the target volume determination in the radiation treatment planning, there are fundamental limitation In use of only the anatomical information. Therefore, the volume determination of the functionally active tumor region using the PET would be important for the treatment planning. However, the accurate determination of the tumor boundary is not simple in PET due to the relatively low spatial resolution of the currently available PET scanners. In this study, computer simulations were peformed to study the relationship between the lesion size, PET resolution, lesion to background ratio and the threshold of Image Intensity to determine the true tumor volume.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10193-10198
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• 2015

Background: Cancer is a major cause of mortality in developing countries and correct and valid information about the epidemiology of this disease is the first step in the planning of health care in each region. The aim of this study was to determine the relative frequency, mean age and sex ratio of the most 10 common non-skin cancers in the world and Iran, among patients referred to an oncology clinic. Materials and Methods: This descriptive study was conducted in Mashhad, north east of Iran. The data obtained from the records of patients referred to the private oncology center between the years of 1985-2012". According to the latest report of GLOBOCAN study commonest malignancies included were lung, breast, colorectal, prostate, stomach, liver, cervix, esophageal, bladder cancers and Non-Hodgkin lymphoma. Results: A total of 4,606 cases were analyzed. The mean age was $55.5{\pm}13.8years$ (male: $59.5{\pm}13.9$, female: $52.6{\pm}12.9$). Overall, breast cancer (1,264 cases, relative frequency of 27.4%) was the most prevalent cancer; however the mean ages of diagnosis were not significantly different between 5-year time period divisions (p=0.290). The most common cancer in men was esophageal cancer (26.3%).The lowest mean age was related to women diagnosed with breast cancer ($48.5{\pm}11.8$) and men with non-Hodgkins lymphoma ($48.4{\pm}17.8$). There were statistically significant differences between the mean age of men and women with gastric (p=0.003) and esophageal cancers (p<0.001). Male to female sex ratios in our study for bladder, lung and stomach cancers were 6.57, 2.60 and 2.50 respectively. Conclusions: The results showed that breast cancer tends to be found in younger female patients and bladder cancer appears more often in men. Screening in target population in addition to early diagnosis may reduce death and disability.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.97-103
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• 2006

The purpose of this study is to understand preliminary education. level of understanding and the degrees of educational requirement for cancer patients on radiotherapy and to present the preliminary data to development of effective and practical patients treatment programs. Based on the abovementioned results of this study. Relationship betweendegrees of knowledge and demand for educational requirement for patients who are undertaking radiotherapy could be varied with different factors such as educational background, ages, regions of treatment, experience of symptoms. In general, patients do not have enough information, on the other hand, have very high demand for educational requirement. Customized education patients by patients would not be possible in reality. However, if we could provide standard for patients and establish systematic sessions during treatment based on this study, more and better patients satisfaction and results of treatments could be achieved.

• Journal of Nutrition and Health
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• v.46 no.3
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• pp.250-260
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• 2013

The purposes of this study were 1) to investigate eating behaviors and patterns in breast cancer patients using a newly developed food frequency questionnaire and 2) to examine perception and use of nutritional information about breast cancer treatment among cancer patients treated with radiation therapy. Sixty breast cancer patients (case group) undergoing radiation therapy in Ajou University Hospital, Suwon, South Korea and 79 healthy women (control group) participated in this study. Mean age of subjects in the control group was $46.00{\pm}7.88$ years and BMI was $23.12{\pm}2.85kg/m^2$, and that of the case group was $50.06{\pm}11.64$ years and $22.32{\pm}3.24kg/m^2$. The results of eating behaviors showed several significant differences between control and case groups. Breast cancer patients ate meals on a more regular basis, on time, and more frequently compared to control subjects. In addition, they preferred more salty or spicy and bland food compared to healthy women. According to answers from the food frequency questionnaire, breast cancer patients consumed significantly lower amounts of boiled white rice, meats and processed food, fish and shellfish, coffee, milk, and cheese, whereas they consumed a significantly large amount of boiled multigrain rice, vegetable, seaweeds, soybean and processed food, and yoghurt compared to healthy women. This study also observed the way in which cancer patients and healthy control subjects obtain information about breast cancer treatment and its reliabilities. Results showed that healthy women did not hesitate to obtain information from mass media, while breast cancer patients would obtain nutritional information from specialists rather than mass media. Results of this survey confirmed that breast cancer patients avoided intake of red meat protein, even though they already recognized the importance of dietary protein intake for recuperation and treatment of the disease. These results could be used for future diet and nutrition guidelines for breast cancer patients.

• Progress in Medical Physics
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• v.21 no.2
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• pp.153-164
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• 2010

To determine the clinical target volumes considering vascularity and cellularity of tumors, the software was developed for mapping of the analyzed biological clinical target volumes on anatomical images using regional cerebral blood volume (rCBV) maps and apparent diffusion coefficient (ADC) maps. The program provides the functions for integrated registrations using mutual information, affine transform and non-rigid registration. The registration accuracy is evaluated by the calculation of the overlapped ratio of segmented bone regions and average distance difference of contours between reference and registered images. The performance of the developed software was tested using multimodal images of a patient who has the residual tumor of high grade gliomas. Registration accuracy of about 74% and average 2.3 mm distance difference were calculated by the evaluation method of bone segmentation and contour extraction. The registration accuracy can be improved as higher as 4% by the manual adjustment functions. Advanced MR images are analyzed using color maps for rCBV maps and quantitative calculation based on region of interest (ROI) for ADC maps. Then, multi-parameters on the same voxels are plotted on plane and constitute the multi-functional parametric maps of which x and y axis representing rCBV and ADC values. According to the distributions of functional parameters, tumor regions showing the higher vascularity and cellularity are categorized according to the criteria corresponding malignant gliomas. Determined volumes reflecting pathological and physiological characteristics of tumors are marked on anatomical images. By applying the multi-functional images, errors arising from using one type of image would be reduced and local regions representing higher probability as tumor cells would be determined for radiation treatment plan. Biological tumor characteristics can be expressed using image registration and multi-functional parametric maps in the developed software. The software can be considered to delineate clinical target volumes using advanced MR images with anatomical images.