• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.8-14
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• 2012

Background: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. Methods: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second ($FEV_1$)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with $FEV_1$ - the index of the severity of airflow limitation. Results: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient ${\beta}$=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; ${\beta}$=-0.24; p<0.001), and airway wall thickness (mean wall area %; ${\beta}$=-0.19, p=0.001), as well as current smoking status (${\beta}$=-0.14; p=0.009) were independent contributors to $FEV_1$. Conclusion: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.123-135
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• 2012

Purpose: It is essential to minimize the movement of tumor due to respiratory movement at the time of respiration controlled radiotherapy of non-small cell lung cancer patient. Accordingly, this Study aims to evaluate the usefulness of restricted respiratory period by comparing and analyzing the treatment plans that apply free and restricted respiration period respectively. Materials and Methods: After having conducted training on 9 non-small cell lung cancer patients (tumor n=10) from April to December 2011 by using 'signal monitored-breathing (guided- breathing)' method for the 'free respiratory period' measured on the basis of the regular respiratory period of the patents and 'restricted respiratory period' that was intentionally reduced, total of 10 CT images for each of the respiration phases were acquired by carrying out 4D CT for treatment planning purpose by using RPM and 4-dimensional computed tomography simulator. Visual gross tumor volume (GTV) and internal target volume (ITV) that each of the observer 1 and observer 2 has set were measured and compared on the CT image of each respiratory interval. Moreover, the amplitude of movement of tumor was measured by measuring the center of mass (COM) at the phase of 0% which is the end-inspiration (EI) and at the phase of 50% which is the end-exhalation (EE). In addition, both observers established treatment plan that applied the 2 respiratory periods, and mean dose to normal lung (MDTNL) was compared and analyzed through dose-volume histogram (DVH). Moreover, normal tissue complication probability (NTCP) of the normal lung volume was compared by using dose-volume histogram analysis program (DVH analyzer v.1) and statistical analysis was performed in order to carry out quantitative evaluation of the measured data. Results: As the result of the analysis of the treatment plan that applied the 'restricted respiratory period' of the observer 1 and observer 2, there was reduction rate of 38.75% in the 3-dimensional direction movement of the tumor in comparison to the 'free respiratory period' in the case of the observer 1, while there reduction rate was 41.10% in the case of the observer 2. The results of measurement and comparison of the volumes, GTV and ITV, there was reduction rate of $14.96{\pm}9.44%$ for observer 1 and $19.86{\pm}10.62%$ for observer 2 in the case of GTV, while there was reduction rate of $8.91{\pm}5.91%$ for observer 1 and $15.52{\pm}9.01%$ for observer 2 in the case of ITV. The results of analysis and comparison of MDTNL and NTCP illustrated the reduction rate of MDTNL $3.98{\pm}5.62%$ for observer 1 and $7.62{\pm}10.29%$ for observer 2 in the case of MDTNL, while there was reduction rate of $21.70{\pm}28.27%$ for observer 1 and $37.83{\pm}49.93%$ for observer 2 in the case of NTCP. In addition, the results of analysis of correlation between the resultant values of the 2 observers, while there was significant difference between the observers for the 'free respiratory period', there was no significantly different reduction rates between the observers for 'restricted respiratory period. Conclusion: It was possible to verify the usefulness and appropriateness of 'restricted respiratory period' at the time of respiration controlled radiotherapy on non-small cell lung cancer patient as the treatment plan that applied 'restricted respiratory period' illustrated relative reduction in the evaluation factors in comparison to the 'free respiratory period.

• Progress in Medical Physics
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• v.19 no.4
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• pp.263-268
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• 2008

The application of a respiratory gated radiotherpy method to the lung radiation surgery was evaluated compared with the conventional method in which the whole tumor motion range is considered in the delineation of PTV (Planning target volume). The four dimensional CT simulation images were acquired for the five NSCLC (Non-small cell lung cancer) patients for radiation surgery. The respiratory gated plan was prepared with the 50% phase CT images and the conventional method was planned based on the ITV (Internal target volume) which include all the target volumes created in each phase CT images within a whole respiratory period. The DVH (Dose volume histogram) of OAR (Organ at risk) which calculated in each method was compared for the evaluation of the plan properness. The relative decrease of OARs' DVH were verified in the application of respiratory gated method. The average decrease rate were $16.88{\pm}9.97%$ in the bronchus, $34.13{\pm}19.15%$ in the spinal cord, $28.42{\pm}18.49%$ in the chest wall and $32.48{\pm}16.66%$ in the lung. Based on these results, we can verified the applicability and the effectiveness of the respiratory gated method in the lung radiation surgery.

• The Journal of Korean Medicine
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• v.31 no.3
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• pp.34-46
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• 2010

Objective: This experimental study was performed to examine if Hang-Am-Dan non-boiled water extracts (HAD-N) induce apoptosis in human lung carcinoma NCI-H460 cells in vitro and inhibits the growth of NCI-H460 cell-transplanted solid tumor in vivo. Materials and Methods: We cultured NCI-H460 cell lines and xenografted them to nude mice. The mice were divided into 3 groups, NCI-H460 cell alone, NCI-H460 + 90 mg/kg HAD-N treated group, and NCI-H460 + 180 mg/kg HAD-N treated group, with seven mice per group. HAD-N was orally administrated every day for four weeks. We checked their body weight and tumor weight and volumes two times a week and their absolute organ weight and biochemical blood analysis at the final day by sacrificing them. We also calculated their tumor inhibition rate (IR), mean survival time and percent increase in life span (% ILS). Results: In this study, we observed that all of the HAD-N treated mice got smaller tumors. The more doses of HAD-N used, the less IR showed at the 8th day after starting this experiment. Tumor weight and volume of HAD-N treatment groups also decreased. Mean survival time and percent increase in life span (% ILS) in the high-dose HAD-N treatment groups were higher than those of other groups. The test substances in the blood level UN results showed reduction in the significance in both HAD-N 90 mg/kg and HAD-N 180 mg/kg (p<0.01). The blood level phosphatase results in HAD-N 90 mg/kg group compared to NCI-H460 cell alone group showed a reduction in significance (p<0.05). AST levels HAD-N 180 mg/kg group compared to NCI-H460 cell alone group significance as well (p<0.05). Conclusion: We suggest that the results of the in vivo study showed that HAD-N may have potential as a growth inhibitor of tumor-induced NCI-H460 of nude mice in spite of the shortcomings of this study. More studies to overcome those shortcomings and to find out significant antitumor mechanism will be needed.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.243-248
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• 2023

This study aims to analyze the secondary carcinogenesis rate caused by exposure of organs at risk of damage using a glass dosimeter during radiosurgery in vestibular schwannoma disease. Using a pediatric phantom of human tissue equivalent material, the volume of the tumor was set to a total of three volumes: 0.506 cm³, 1.008 cm³, and 2.032 cm³, and a radiosurgery plan was established with an average dose of 18.4 ± 3.4 Gy. After mounting the human body phantom on the table of surgical equipment, glass dosimeters were placed on the right eye, left eye, thyroid gland, thymus, right lung, and left lung to measure the exposure dose, respectively. In this study, the incidence of secondary cancer due to exposure to damaged organs during gamma knife radiosurgery in vestibular schwannoma disease with the largest tumor volume of 2.032 cm³ was measured with a glass dosimeter. This study studies the risk of secondary radiation exposure dose that can occur during stereotactic radiosurgery, and it is considered that it will be used as basic data in the field of radiation damage related to the stochastic effect of radiation in the future.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.88-93
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• 2003

Whether respiratory muscle training is of benefit to the singing students is controversial. The purpose of the study is to investigate pulmonary function and the maximal inspiratory(MIP) and expiratory pressure(MET), and maximum phonation time in five female singing students before and after the specially programmed respiratory muscle training during 2 months. All singing students had average 4.8 years of formal classical voice training. Respiratory muscle training machine (Ultrabreath) was used to train respiratory muscle. Pulmonary function test data on simple pulmonary function, flow volume curve, static lung volumes are obtained from Vmax 6200. The MIP and MEP were measured using Spirovis, and the MPT were measured using hand-held stopwatch. Any pulmonary function test variables are not changed after respiratory muscle training. However, MIP and MEP were significantly increased between before and after respiratory muscle training. MPT increased significantly after training, compared to the pre-trained. MIP, MEP, and MPT after training in female singing students were 26%, 25% and 33% higher than those before training. The result indicated that the specially programmed respiratory muscle training is beneficial to improve respiratory muscle strength and vocal function without an increment in pulmonary function.

• Radiation Oncology Journal
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• v.34 no.2
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• pp.145-155
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• 2016

Purpose: Radiation therapy targeting axilla and groin lymph nodes improves regional disease control in locally advanced and high-risk skin cancers. However, trials generally used conventional two-dimensional radiotherapy (2D-RT), contributing towards relatively high rates of side effects from treatment. The goal of this study is to determine if three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or volumetric-modulated arc therapy (VMAT) may improve radiation delivery to the target while avoiding organs at risk in the clinical context of skin cancer regional nodal irradiation. Materials and Methods: Twenty patients with locally advanced/high-risk skin cancers underwent computed tomography simulation. The relevant axilla or groin planning target volumes and organs at risk were delineated using standard definitions. Paired t-tests were used to compare the mean values of several dose-volumetric parameters for each of the 4 techniques. Results: In the axilla, the largest improvement for 3D-CRT compared to 2D-RT was for homogeneity index (13.9 vs. 54.3), at the expense of higher lung $V_{20}$ (28.0% vs. 12.6%). In the groin, the largest improvements for 3D-CRT compared to 2D-RT were for anorectum $D_{max}$ (13.6 vs. 38.9 Gy), bowel $D_{200cc}$ (7.3 vs. 23.1 Gy), femur $D_{50}$ (34.6 vs. 57.2 Gy), and genitalia $D_{max}$ (37.6 vs. 51.1 Gy). IMRT had further improvements compared to 3D-CRT for humerus $D_{mean}$ (16.9 vs. 22.4 Gy), brachial plexus $D_5$ (57.4 vs. 61.3 Gy), bladder $D_5$ (26.8 vs. 36.5 Gy), and femur $D_{50}$ (18.7 vs. 34.6 Gy). Fewer differences were observed between IMRT and VMAT. Conclusion: Compared to 2D-RT and 3D-CRT, IMRT and VMAT had dosimetric advantages in the treatment of nodal regions of skin cancer patients.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.27.1-27.10
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• 2020

The efficacies of a supraglottic airway device (SGAD) and an endotracheal tube (ETT) in cats under general anesthesia with volume-controlled ventilation (VCV) were compared. Thirty healthy cats were randomly allocated for airway control using either an SGAD or an ETT. Five tidal volumes (6, 8, 10, 12, and 14 mL/kg) were randomly tested, and respiratory rates were adjusted to achieve a minute ventilation of 100 mL/kg/min. The dose of propofol necessary to insert the SGAD or ETT, the static respiratory pressure, leakage during VCV, and end tidal CO₂ (ETCO₂) were recorded. Dosages of propofol and static respiratory measurements for the SGAD and ETT groups were compared using a t-test. The distribution of leakages and hypercapnia (ETCO₂ > 45 mmHg) were compared using Fisher's exact test. A significance level of p < 0.05 was established. No significant difference in dose of propofol was observed between the SGAD and ETT groups (7.1 ± 1.0, 7.3 ± 1.7 mg/kg; p = 0.55). Static resistance pressure of the SGAD (22.0 ± 8.1 cmH₂O/L/sec) was significantly lower than that of the ETT (36.6 ± 12.9 cmH₂O/L/sec; p < 0.01). Of the 75 trials, leakage was more frequent when using an SGAD (8 events) than when using an ETT (1 event; p = 0.03). Hypercapnia occurred more frequently with SGAD (18 events) than with ETT (3 events; p < 0.01). Although intubation with an ETT is the gold standard in small animal anesthesia, the use of an SGAD can reduce airway resistance and the work of breathing. Nonetheless, SGAD had more dead space and the tidal volume for VCV needs adjustment.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.420-430
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• 2023

Background: This study provides an update to a landmark 2004 report describing demographics, training, and trends in adherence to thoracic surgery practice standards in Canada. Methods: An updated questionnaire was administered to all members of the Canadian Association of Thoracic Surgeons via email (n=142, compared to n=68 in 2004). Our report incorporates internal data from Ontario Health and the Canadian Partnership Against Cancer. Results: Forty-eight surgeons completed the survey (male, 70.8%; mean±standard deviation age, 50.3±9.3 years). This represents a 33.8% response rate, compared to 64.7% in 2004. Most surgeons (69%) served a patient population of over 1 million per center; 32%-34% reported an on-call ratio of 1:4-1:5 days, and the average weekly hours worked was 56.4±11.9. Greater access to dedicated geographic units per center (73% in 2021 vs. 53% in 2004) has improved thoracic-associated services and house staff, notably endoscopy units (100% vs. 91%), with 73% of respondents having access to both endobronchial and endoscopic ultrasound. Access to thoracic radiology has also improved, particularly regarding positron emission tomography scanners per center (76.9% vs. 13%). Annual case volumes for lung (255 vs. 128), esophageal (41 vs. 19), and mediastinal resections (30 vs. 13), along with hiatal hernia repair (45 vs. 20), have increased substantially despite reports of operating room availability and radiology as rate-limiting steps. Conclusion: This survey characterizes compliance with current practice standards, addressing the needs of thoracic surgeons across Canada. Over 85% of respondents were aware of the 2004 compliance paper, and 35% had applied for resources and equipment in response.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.228-239
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• 2009

Purpose: 4DCT scans performed for radiotherapy were retrospectively analyzed to assess the possible benefits of respiratory gating in non-small cell lung cancer (NSCLC) and established the predictive factors for identifying patients who could benefit from this approach. Materials and Methods: Three treatment planning was performed for 15 patients with stage I~III NSCLC using different planning target volumes (PTVs) as follows: 1) PTVroutine, derived from the addition of conventional uniform margins to gross tumor volume (GTV) of a single bin, 2) PTVall phases (patient-specific PTV), derived from the composite GTV of all 6 bins of the 4DCT, and 3) PTVgating, derived from the composite GTV of 3 consecutive bins at end-exhalation. Results: The reductions in PTV were 43.2% and 9.5%, respectively, for the PTVall phases vs. PTVroutine and PTVgating vs. PTVall phases. Compared to PTVroutine, the use of PTVall phases and PTVgating reduced the mean lung dose (MLD) by 18.1% and 21.6%, and $V_{20}$ by 18.2% and 22.0%, respectively. Significant correlations were seen between certain predictive factors selected from the tumor mobility and volume analysis, such as the 3D mobility vector, the reduction in 3D mobility and PTV with gating, and the ratio of GTV overlap between 2 extreme bins and additional reductions in both MLD and $V_{20}$ with gating. Conclusion: The additional benefits with gating compared to the use of patient-specific PTV were modest; however, there were distinct correlations and differences according to the predictive factors. Therefore, these predictive factors might be useful for identifying patients who could benefit from respiratory-gated radiotherapy.