• 한국대기환경학회지
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• 제19권5호
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• pp.551-560
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• 2003

Particle deposition in human lungs was investigated theoretically by using asymmetric five-lobe lung model. The volumes of each of the five lobes were different, thereby forming an asymmetric lung structure. The tidal volume and flow rate of each lobe were scaled according to lobar volume. The total and regional deposition with various breathing patterns were calculated by means of tracking volume segments and accounting for particle loss during inhalation and exhalation. The deposition fractions were obtained for each airway generation and lung lobe, and dominant deposition mechanisms were investigated for different size particles. Results show that the tidal volume and flow rate have a characteristic influence on particle deposition. The total deposition fraction increases with an increase in tidal volume for all particle sizes. However, flow rate has dichotomous effects: a higher flow rate results in a sharp increase in deposition for large size particles, but decreases deposition for small size particles. Deposition distribution within the lung shifts proximally with higher flow rate whereas deposition peak shifts to the deeper lung region with larger tidal volume. Deposition fraction in each lobe was proportional to its volume. Among the three main deposition mechanisms, diffusion was dominant for particles < 0.5 ${\mu}{\textrm}{m}$ whereas sedimentation and impaction were most influential for larger size particles. Impaction was particularly dominant for particles> 8 ${\mu}{\textrm}{m}$. The results may prove to be useful for estimating deposition dose of inhaled pollutant particles at various breathing conditions.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3253-3260
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• 2014

Background: A case-control study was conducted to evaluate the effect of household exposure, dietary habits, smoking and Glutathione S-Transferases M1, T1 polymorphisms on lung cancer among women in Mizoram, India. Materials and Methods: We selected 230 newly diagnosed primary lung cases and 460 controls from women in Mizoram. Multivariate logistic regression analysis was performed to estimate adjusted odds ratio (OR). Results: Exposure of cooking oil fumes (p<0.003), wood as heating source for cooking (p=0.004), kitchen inside living room (p=0.001), improper ventilated house (p=0.003), roasting of soda in kitchen (p=0.001), current smokers of tobacco (p=0.043), intake of smoked fish (p=0.006), smoked meat (p=0.001), Soda (p<0.001) and GSTM1 null genotype (p=0.003) were significantly associated with increased risk of lung cancer among women in Mizoram. Significantly protective effect was observed for intake of bamboo shoots (p=<0.001) and egg (p<0.001). A clear increase in dose response gradient was observed for total cooking dish years. Risk for lung cancer tends to increase with collegial effect of indoor environmental sources (p=0.022). Significant correlation was also observed for interaction of GST polymorphisms with some of dietary habits. Conclusions: We confirmed the important role of exposure of cooking oil emission and wood smoke, intake of smoked meat, smoked fish and soda (an alkali preparation used as food additives in Mizoram) and tobacco consumption for increase risk of lung cancer among Women in Mizoram.

• 대한방사선치료학회지
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• 제1권1호
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• pp.79-83
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• 1985

Carcinoma of the breast has been treated by surgery followed by irradiation of the chest wall and regional lymphatics treatment planning of the breast cancer is required that lung must be spared as much as possible. However megavoltage irradiation of the internal mammary chain results in high dose to underlying heart, esophagus and spinal cord. Electron beam can be used for the irradiation of the internal mammary chain instead of megavoltage beam. We studied dose distribution of single anterior electron field, compared with traditional treatment methods. 12 and 15MeV electron beam with bolus has good dose distribution to spare underlying lung tissue and other organs.

• Radiation Oncology Journal
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• 제25권2호
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• pp.109-117
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• 2007

목 적: 유방암 환자에서 보조적 방사선치료 후 호흡기 증상을 동반한 방사선 폐렴(SRP) 및 방사선학적 폐 독성(RPT)의 빈도 및 이에 영향을 미치는 예측인자를 알아보고자 하였다. 특히 3차원 방사선계획에서 얻은 선량체적히스토그람(DVH) 인자와 RTP의 상관관계를 중심으로 분석해보고자 하였다. 대상 및 방법: 2003년 9월부터 2006년 2월까지 171명의 환자가 유방암으로 수술 후 방사선치료를 받았다. 2개의 tangential photon 조사야가 통상적으로 사용되었고, 액와부 림프절 전이 정도에 따라 anterior oblique photon 조사야를 추가하였다. 유방 보존술 후 보조적 방사선치료를 받은 침윤성 유방암 환자에는 전자선을 이용한 boost가 적용되었다. 방사선 치료 후의 정기추적 흉부 단순촬영소견을 흉부방사선전문의와 함께 검토, 분석하였다. RTOG 특성기준 및 modified WHO grading system을 적용하였다. 조사받은 방사선량에 따라 $V_{15},\;V_{20},\;V_{30}$ 및 mean lung dose (MLD)를 구하되, 동측 폐를 tangential 및 SCL 영역으로 구분하여, 각각의 DVH parameters 즉 $V_{15\;TNGT},\;V_{20\;TNGT},\;V_{30\;TNGT},\;MLD_{TNGT}$ 및 $V_{15\;SCL},\;V_{20\;SCL},\;V_{30\;SCL},\;MLD_{SCL}$을 구하여 RPT와의 상관관계를 분석하였다. 결 과: 호흡기 증상을 동반한 방사선 폐렴(SRP)이 4예(2.1%)에서 발생하였다(RTOG grade 3가 3예 grade 1이 1예). 나이 흡연여부, 기존폐질환유무, 항암요법, 호르몬치료, regional RT 여부 등은 SRP와 무관하였다. 3-RTP가 시행된 137예 중 13.9%에서 tangential 영역에 RPT가 발생하였다. Regional RT를 받은 59 중 49.2%에서 SCL 영역에 RPT가 발생하였다. Regional RT 유무(p<0.001), 환자의 나이(p=0.039), V15 TNGT를 제외한 모든 DVH parameter들이 RPT와 유의한 상관관계를 나타내었다. $MLD_{TNGT}$는 TNGT 영역의 RPT를, $V_{15\;SCL}$는 SCL 영역의 RPT를 예측하기에 적합한 것으로 분석되었다. 결 론: 본 연구에서 SRP의 빈도는 매우 낮았다. Regional RT 여부와 환자의 나이, DVH parameter들이 RPT와 유의한 상관관계를 나타내었으며, $MLD_{TNGT}$는 TNGT 영역에서, $V_{15\;SCL}$는 SCL 영역에서 RPT의 유의한 예측인자였다.

• Journal of Radiation Protection and Research
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• 제16권1호
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• pp.1-13
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• 1991

국내 12개 지역의 340여 실내에서 측정한 라돈농도로부터 단순한 수학적 폐선량 평가모형을 이용하여 주민의 실효선량당량을 평가하였다. 수동적 시간적분형 CR-39 라돈컵으로 1990년 4월부터 10월까지 $3{\sim}4$개월 동안 측정 한 실내의 라돈농도는 지역별로 $33.82{\sim}61.42 Bq/m^3$(평균 : $48.90 Bq/m^3$)의 분포를 보였으며, 이로 인한 라돈자핵종의 평형등가라 돈농도$(EEC_{Rn})$는 라돈과 자핵종간의 평형인자의 값 0.4를 적용했을 때 $13.53{\sim}24.57Bq/m^3$(평균 : $19.55 Bq/m^3$)으로 예상되었다. 국제방사선방어위원회의 폐모형에 근거한 본 연구의 폐선량 평가모형에서 유도된 단위 평형등가라돈농도의 피폭당 실효선량당량환산 인자는 $1.07{\times}10^{-5}\;mSv/Bq\;h\;m^{-3}$으로 국제방사선방어위원회나 국제연합 방사선영향평가 과학위원회(UNSCEAR)에서 권고한 값과 잘 일치하였다. 동 선량환산인자와 CR-39 라돈 컵으로 측정 한 실내 의 평균 평형등가라돈농도를 년간 $0.75 m^3/h$의 호흡율로 호흡한 것으로 가정했을 때, 주민이 받는 년평균 폐선량당량 및 실효선량당량은 갹각 20.90 mSv 및 1.25 mSv인 것으로 평가되었다. 동 피폭선량은 국제연합(UNSCEAR)에서 1988년에 발표한 일반인의 년평균 자연방사선피폭 실효선량당량인 2.40mSv의 거의 50%에 상당하였다.

• Radiation Oncology Journal
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• 제2권1호
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• pp.149-153
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• 1984

Postoperative radiotherapy of breast cancer makes it possible to reduce loco-regional recurrence of breast cancer. The treatment technique, which can reduce the low-dose region at the junction and lung, is required. To produce proper dose distribution of internal mammary chain and chest wall, authors tried to find the method to expose $^{60}Co\;\gamma-ray$ on internal mammary region and 7MeV electron on chest wall. Exposure time of $^{60}Co\;\gamma$ and monitor unit of 9MeV were selected so that dose of $^{60}Co$ at 4cm depth was the same as that of 7Mev electron at $80\%$ dose depth. The position and direction of electron beam were changed for $^{60}Co$ beam: $0^{\circ},\;5^{\circ}$ for 0cm seperation; $0^{\circ},\;5^{\circ},\;10^{\circ}$ for 0.5cm seperation; $5^{\circ},\;10^{\circ},\;15^{\circ}$ for 1cm seperation. The results are as followings. 1. When the seperation of two fields was increased, dose on the axis of $^{60}Co$ beam was increased and dose at the junction region decreased while the volume of lung to be exposed to high dose and hot spot size were irregularly changed. 2. The dose distribution in the target volume of internal mammary and chest wall was most ideal when the seperation of two fields was $0\~0.5cm$ and the direction of electron beam was parallel to $^{60}Co$ beam.

• Journal of Trauma and Injury
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• 제34권3호
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• pp.162-169
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• 2021

Purpose: For severe lung injuries or acute respiratory distress syndrome that occurs during critical care due to trauma, extracorporeal membrane oxygenation (ECMO) may be used as a salvage treatment. This study aimed to describe the experiences at a single center with the use of ECMO in trauma patients. Methods: We enrolled a total of 25 trauma patients who were treated with ECMO between January 2015 and December 2019 at a regional trauma center. We analyzed and compared patients' characteristics between survivors and non-survivors through a medical chart review. We also compared the characteristics of patients between direct and indirect lung injury groups. Results: The mean age of the 25 patients was 45.9±19.5 years, and 19 patients (76.0%) were male. The mean Injury Severity Score was 26.1±10.1. Ten patients (40.0%) had an Abbreviated Injury Scale (AIS) 3 score of 4, and six patients (24.0%) had an AIS 3 score of 5. There were 19 cases (76.6%) of direct lung injury. The mortality rate was 60.0% (n=15). Sixteen patients (64.0%) received a loading dose of heparin for the initiation of ECMO. There was no significant difference in heparin use between the survivors and non-survivors (70% in survivors vs. 60% in non-survivors, p=0.691). When comparing the direct and indirect lung injury groups, there were no significant differences in variables other than age and ECMO onset time. Conclusions: If more evidence is gathered, risk factors and indications will be identified and we expect that more trauma patients will receive appropriate treatment with ECMO.

• Journal of Radiation Protection and Research
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• 제20권1호
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• pp.16-24
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• 1995

활성탄 캐니스터법과 알파분광분석 법을 이용하여 실내 공기중의 $^{222}Rn$ 및 그 딸핵종의 농도와 $^{222}Rn$과 그 딸핵종 사이의 평형인자를 동시에 측정하였다. 실내 체재율을 0.8, 일반인과 작업종사자의 호흡율을 각각 $0.75m^3\;h^{-1}$와 $1.2m^3\;h^{-1}$로 가정하고, 실내 공기중의 $^{222}Rn$과 그 딸핵종의 흡입에 의한 부위별 폐선량을 세가지 모형 즉, Jacobi-Eisfeld, James-Birchall 및 ICRP 모형으로 평가하고 연간총유효선량을 평가하였다.

• Tuberculosis and Respiratory Diseases
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• 제65권6호
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• pp.457-463
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• 2008

연구배경: 호기말에 흉부 촬영을 시행하면 폐 내의 공기의 부피가 감소되어 폐 감쇄도가 증가한다. 이런 폐 감쇄도의 변화가 국소적으로 저하되는 공기 가둠 현상에 대해서는 일부 연구들이 있었으나 전체 폐의 전반적인 감쇄도 변화에 대한 연구는 거의 없고, 특히 정상인을 대상으로 한 연구는 거의 없다. 저자들은 호흡기 질환이 없으며 폐기능 및 흡기 전산화단층촬영이 정상 소견이고 호기 영상에서 국소적인 공기 가둠 현상이 없는 100명을 대상으로 연구를 수행하였다. 방 법: 흉부 전산화단층촬영 영상에서 24개의 지점을 정하고, 흡기 및 호기 시 각 지점에서 폐 음영도를 측정한 후 호기말 폐 감쇄도 증가와 흡연량, 연령 사이의 상관 관계를 알아보았다. 결 과: 연구 대상 100명의 연령은 중앙값 49.0세(범위 25~71세)였고, 평균 흡연량은 $22.5{\pm}17.0$갑년이었다. 연령과 폐 감쇄도의 증가 사이에는 유의한 음의 상관관계가 있었으며 이는 흡연의 효과를 보정하였을 때에도 유지되었고, 연령을 기준으로 세 군으로 나누어 폐 감쇄도의 증가 정도를 비교하였을 때에도 유의한 차이가 있었다. 흡연량과 호기말 폐 감쇄도의 증가 사이에는 유의한 음의 상관관계가 관찰되었으나 연령을 보정하였을 때에는 유의성이 감소하였다. 결 론: 흡기-호기 시의 폐의 전반적인 감쇄도 변화 정도는 연령과 상관관계가 있으며, 노화를 반영할 가능성이 있다.

• Radiation Oncology Journal
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• 제38권2호
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• pp.109-118
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• 2020

Purpose: Hypofractionated radiotherapy (RT) is becoming a new standard in postoperative treatment of patients with early stage breast cancer after breast conservation surgery. However, data on hypofractionation in patients with advanced stage disease who undergo mastectomy followed by local and regional nodal irradiation (RNI) is lacking. In this retrospective study, we report late-term effects of 3 weeks post-mastectomy hypofractionated local and RNI with two-dimensional (2D) technique in patients with stage II and III breast cancer. Methods: Between January 1990 and December 2007, 1,770 women with breast cancer who were given radical treatment with mastectomy, systemic therapy and RT at least 10 years ago were included. RT dose was 35 Gy/15 fractions/3 weeks to chest wall by two tangential fields and 40 Gy in same fractions to supraclavicular fossa (SCF) and internal mammary nodes (IMNs). SCF and IMNs dose was prescribed at d_max and 3 cm depth, respectively. Chemotherapy and hormonal therapy was given in 64% and 74% patients, respectively. Late-term toxicities were assessed with the Radiation Therapy Oncology Group (RTOG) scores and LENT-SOMA scales (the Late Effects Normal Tissue Task Force-Subjective, Objective, Management, Analytic scales). Results: Mean age was 48 years (range, 19 to 75 years). Median follow-up was 12 years (range, 10 to 27 years). Moderate/marked arm/shoulder pain was reported by 254 (14.3%) patients. Moderate/marked shoulder stiffness was reported by 219 (12.3%) patients. Moderate/marked arm edema was seen in 131 (7.4%) patients. Brachial plexopathy was not seen in any patient. Rib fractures were noted in 6 (0.3%) patients. Late cardiac and lung toxicity was seen in 29 (1.6%) and 23 (1.3%) patients, respectively. Second malignancy developed in 105 (5.9%) patients. Conclusion: RNI with 40 Gy/15 fractions/3 weeks hypofractionation with 2D technique seems safe and comparable to historical data of conventional fractionation (ClinicalTrial.gov Registration No. NCT04175821).