The indicators of selecting patients with breast cancer undergoing postoperative radiotherapy for deep inspiration breath hold technique / 中华放射肿瘤学杂志

Cardiotoxicity caused by postoperative radiotherapy can increase the risk of cardiovascular adverse events in patients with breast cancer, especially those with left breast cancer, which is proportional to the dose of radiation to the heart. It has been proved that deep inspiration breath-hold (DIBH) technique can significantly reduce the cardiac dose in patients with left breast cancer, but the benefits of this technique vary greatly among different patients, and its implementation requires additional equipment, time, manpower and other resources. Hence, it is necessary to select patients who are suitable for this technique in advance. In addition to comprehensive analysis of general factors before simulation positioning that affect DIBH selection, this review also systematically summarized relevant indicators of CT simulation positioning images. These anatomical indicators included the measurement of the cardiac contact distances in parasagittal (CCD ps) plane, the lateral heart-to-chest distance (HCD), the product of maximum heart width (HW max) and the maximum heart depth (HD max) during CT simulation positioning, and the maximum heart distance, heart volume in the irradiation field (HVIF), the difference of lung volume and heart volume between free breathing (FB) and DIBH measured after CT localization. All of them showed some instructive significance for evaluating whether DIBH should be applied in tangent field based radiotherapy planning. The automatic planning (rapid plan) function in the treatment planning system could quickly predict the benefit of DIBH for breast cancer patients. The purpose of this article is to help clinicians select patients who are suitable for DIBH technique, guaranteeing that DIBH technique resources can be used reasonably.

Análise comparativa das doses cardíacas recebidas por pacientes com câncer de mama esquerda planejadas com duas formas alternativas de delineamento do CTV da cadeia mamária interna / Comparative analysis of heart doses received by patients with left breast cancer planned with two alternative internal mamary delineation CTVs

Propósito. Com a publicação, na última década, do resultado de grandes estudos demonstrando a correlação entre a dose de radiação recebida no coração e o aumento de eventos cardíacos adverso. Nosso estudo investiga a possibilidade de reduzir a dose cardíaca de radiação sem utilizar os protocolos ideais de inspiração profunda (DIBH). Metodologia. Analisamos os parâmetros dosimétricos referentes a 43 pacientes recebidas no departamento de radioterapia da Santa Casa de Maceió tratadas com radioterapia adjuvante em mama ou plastrão esquerdos incluindo fossa e cadeia mamária interna (MI). Todas as pacientes foram submetidas a duas tomografias e planejamentos distintos, com e sem inspiração profunda (DIBH), em um protocolo simplificado adequado para a realidade do Sistema Único de Saúde (SUS). Foram analisados os efeitos dosimétricos sobre o volume alvo, o coração, o pulmão esquerdo com o DIBH simplificado e com formas alternativas de delineamento da cadeia mamária interna. Resultados. Em nosso estudo, o protocolo de DIBH simplificado demonstrou uma redução da dose média cardíaca mesmo em pacientes incluindo radiação nodal regional ampla (692 cGy vs 502 cGy - p < 0,0001). As doses médias no ventrículo esquerdo (VE) (1222 cGy vs 857 cGy ­ p < 0,0001), na artéria coronária anterior descendente (LAD) (3739 cGy vs 3345 cGy ­ p = 0,0001) e outros parâmetros como o V25% do coração (12,4% vs 7,7% - p < 0,0001) também se mostraram reduzidas. Os delineamentos alternativos da cadeia mamária interna (MI) não produziram alterações significantes nas doses cardíacas ou pulmonares. O melhor parâmetro para predizer o benefício do DIBH foi a expansibilidade do pulmão esquerdo (r = 0,6 - p < 0,0001), sendo que os pacientes com relação entre o pulmão normal e o inspirado menor que 1,3-1,4 não obtiveram benefício significativo. Doses pulmonares também tiveram melhora estatisticamente significativa com o DIBH (média 1448 cGy vs 1294 cGy ­ p < 0,0001; V20 32,6% vs 28,2% - p <0,0001; V5 48,7% vs 45,4% - p < 0,0005), Conclusão. Nosso estudo indica que um protocolo simplificado de DIBH pode ser uma alternativa para beneficiar pacientes selecionados que necessitam reduzir a dose cárdica de radiação em tratamentos e mama esquerda e drenagens regionais em serviços de radioterapia de alta demanda e recursos limitados

Purpose. In the last decade, seminars studies demonstrated the correlation between radiation doses received in the heart with the incidence of cardiac disease, such as acute coronary events. This aroused the interest in new techniques to reduce this problem. Numerous studies have already shown that Deep Inspiration Breath Hold (DIBH) may be the best option for reducing cardiac dose. However, the vast majority of these investigations were carried out in a different scenario from the one found in our reality. Our study investigated the feasibility of reducing the cardiac dose without using an ideal DIBH protocol, which are difficult to implement in services with high demand and low economic support. Methods. The dosimetric parameters of 43 patients from the radiotherapy department of Santa Casa de Maceió were analyzed. All patients were treated with adjuvant radiotherapy to the left breast, including supraclavicular fossa and internal mammary chain (IM). The patients underwent two different CT scans and planning, with and without DIBH, in a simplified protocol suitable for the reality of tour public health system (Free Breath Hold; no respiratory training; selection of only the patients with greater benefit). The dosimetric impact on the heart, its substructures and the left lung were studied with the simplified DIBH and with alternative forms of delineation to the IM. Results. The simplified DIBH protocol demonstrated, in our study, a reduction in mean cardiac dose for patients including wide regional nodal radiation (692 cGy vs 502 cGy - p < 0.0001). The doses for the Left ventricular (1222 cGy vs 857 cGy ­ p < 0.0001), the Left anterior-descending coronary (3739 cGy vs 3345 cGy ­ p = 0.0001) and other parameters such as heart V25% (12.4% vs 7, 7% - p < 0.0001) were also reduced. The doses to the heart did not achieve statistically significant reduction with alternative delineation of the MI CTV. The best parameter predicting the benefit of DIBH was the left lung expansion (r = 0.6 - p < 0.0001), with patients with a ratio lower than 1.3-1,4 having no significant benefit. Pulmonary doses also showed a statistically significant improvement with DIBH (Dmed 1448 cGy vs 1294 cGy ­ p < 0.0001; V20 32.6% vs 28.2% - p <0.0001; V5 48.7% vs 45, 4% - p < 0.0005), but the reductions were small, as was the increase in pulmonary dose when the MI CTV is outlined to joining the supraclavicular fossa. Conclusion. Our study indicates that a simplified DIBH protocol may serve as an option to benefit selected patients with locally advanced breast cancer treated in departments with high occupation of the Linacs and low capacity for investment in new technology

Current research on surface guided radiation therapy / 中国辐射卫生

Surface guided radiation therapy (SGRT) is a method of radiation therapy with non-invasive and non-radiation image guidance technology, which uses continuous real-time imaging to monitor the whole course of treatment. This paper summarizes the characteristics, representative products, application in clinical research and treatment, and quality control of SGRT. This emerging technology plays an increasingly important role in delivering more precise, safe, and comfortable radiotherapy to patients.

Application of deep inspiration breath-hold technique in radiotherapy / 中华放射肿瘤学杂志

In radiotherapy for thoracic and abdominal tumors, the negative effect of respiratory movement on radiotherapy persist throughout the whole process of radiotherapy. Deep inspiration breath-hold technique (DIBH) is a method of respiratory movement management in radiotherapy, which can reduce the negative effect of respiratory movement upon radiotherapy in the whole process of radiotherapy. Meantime, DIBH technique has its own characteristics and operation requirements compared with other respiratory movement management measures (such as 4D CT, gated technology and tracking, etc.). The aim of this review was to introduce the advantages, disadvantages and the application status of DIBH technique.

An effective patient training for deep inspiration breath hold technique of left-sided breast on computed tomography simulation procedure at King Chulalongkorn Memorial Hospital

PURPOSE: To observe the effectiveness of the practical instruction sheet and the educational video for left-sided breast treatment in a patient receiving deep inspiration breath hold (DIBH) technique. Two parameters, simulation time and patient satisfaction, were assessed through the questionnaire. METHODS: Two different approaches, which were the instruction sheet and educational video, were combinedly used to assist patients during DIBH procedures. The guideline was assigned at least 1 week before the simulation date. On the simulation day, patients would fill the questionnaire regarding their satisfaction with the DIBH instruction. The questionnaire was categorized into five levels: extremely satisfied to dissatisfied, sequentially. The patients were divided into four groups: not DIBH technique, DIBH without instruction materials, the DIBH with instruction sheet or educational video, and DIBH with both of instruction sheet and educational video. RESULTS: Total number of 112 cases of left-sided breast cancer were analyzed. The simulation time during DIBH procedure significantly reduced when patients followed the instruction. There was no significant difference in simulation time on the DIBH procedures between patient compliance via instruction sheet or educational video or even following both of them. The excellent level was found at 4.6 ± 0.1 and 4.5 ± 0.1, for patients coaching via instruction sheet as well as on the educational video, respectively. CONCLUSION: Patient coaching before simulation could potentially reduce the lengthy time in the simulation process for DIBH technique. Practicing the DIBH technique before treatment is strongly advised.

Liver dose reduction by deep inspiration breath hold technique in right-sided breast irradiation

PURPOSE: Deep inspiration breath hold (DIBH) is a well-established technique that enables efficient cardiac sparing in patients with left-sided breast cancer. The aim of the current study was to determine if DIBH is effective for reducing radiation exposure of of liver and other organs at risk in right breast radiotherapy (RT).MATERIALS AND METHODS: Twenty patients with right-sided breast cancer were enrolled in this study. Three-dimensional conformal RT plans were generated for each patient, with two different computed tomography scans of free breathing (FB) and DIBH. Nodes were contoured according to the Radiation Therapy Oncology Group contouring guidelines. Dose-volume histograms for the target volume coverage and organs at risk were evaluated and analyzed.RESULTS: DIBH plans showed significant reduction in mean liver dose (5.59 ± 2.07 Gy vs. 2.54 ± 1.40 Gy; p = 0.0003), V(20Gy) (148.38 ± 73.05 vs. 64.19 ± 51.07 mL; p = 0.0003) and V(10Gy) (195.34 ± 93.57 vs. 89.81 ± 57.28 mL; p = 0.0003) volumes compared with FB plans. Right lung doses were also significantly reduced in DIBH plans. Heart and left lung doses showed small but statistically significant improvement with application of the DIBH technique.CONCLUSION: We report that the use of DIBH for right-sided breast cancer significantly reduces the radiation doses to the liver, lungs, and heart.

Application and set-up error of deep inspiration breath-hold (DIBH) technique for whole breast irradiation in left breast cancer / 中华放射肿瘤学杂志

Objective To analyze the correlation between treatment time and radiotherapy plan of deep inspiration breath-hold (DIBH) technique for the whole breast irradiation (WBI) in the left breast cancer after breast-conserving surgery,verify the inter-fractional reproducibility of radiotherapy,observe the heart location and dosimetric changes and calculate the effect of DIBH upon the WBI setup error after the surgery.Methods We prospectively enrolled 15 patients with left breast cancer undergoing WBI after breast-conserving surgery,who met the requirement of D1BH.Treatment time was recorded,its correlation with the number of field and monitor unit was analyzed.Inter-fractional setup errors and PTV delineation were calculated using cone beam CT (CBCT).The accuracy of the position and dose of the heart during radiotherapy was verified by the imaging fusion of CBCT and CT images.The variables among groups were analyzed by non-parametric Firedman test.Results The average treatment time of DIBH radiotherapy was 4.6 minutes.The treatment time was correlated with the maximal and total number of sub-fields and total monitor units.During DIBH treatment,the mean cardiac displacement volume was 19.1 cm3(3.8％).The mean cardiac dose difference between CBCT and planning CT was 5.1 cGy,and there was no significant difference in the heart V5-V30.The mean inter-fractional system setup error (∑) and random setup error (σ) in the left-right (x),superior-inferior (y) and anterior-posterior (z) direction were ∑x 1.9 mm,∑y 2.1 mm,∑z 2.0 mm,σx 1.3 mm,σy 1.3 mm,σz 1.4 mm,respectively.The corresponding minimal margins for setup error were 5.7 mm,6.2 mm and 6.0 mm,respectively.Conclusion DIBH for WBI after breast-conserving surgery does not significantly prolong the treatment time.Treatment time is related to treatment plan.DIBH yields high inter-fractional reproducibility and protects the heart.

Cardiac dosimetry of deep inspiration breath-hold technique in whole breast irradiation for left breast cancer after breast-conserving surgery / 中华放射肿瘤学杂志

Objective To study the effect of deep inspiration breath-hold(DIBH)technique on the heart dose in whole breast irradiation(WBI)for left breast cancer after breast-conserving surgery, and to investigate the anatomical factors for heart dose. Methods Fifteen patients with left breast cancer who received WBI after breast-conserving surgery and met breathing control requirements were prospectively enrolled as subjects. Simulated CT scans were performed during free breathing(FB)and DIBH. The WBI plans were optimized based on DIBH images.The position,volume,and radiation doses to the heart and lung were compared between the status of FB and DIBH. Correlation of heart dose with various anatomical factors was analyzed in FB status. Between-group comparison of categorical data was made by nonparametric Wilcoxon rank test.A two-variable correlation analysis was made by the Pearson method.Results There was no significant difference in heart volume between the status of FB and DIBH(P=0.773).The volume of both lungs was significantly larger in DIBH status than in FB status(P=0.001). The mean and maximum doses and V5-V40for the heart,left anterior descending coronary artery,left ventricle,right ventricle,and left lung were significantly lower in DIBH status than in FB status(all P<0.05). The greater DIBH increased the lung volume,the greater the mean heart dose decreased. In FB status,the left breast volume,heart-to-lung volume ratio,distance between the inferior margins of breast and heart,and maximum heart margin distance showed a linear correlation with heart dose. Particularly, the heart-to-lung volume ratio and maximum heart margin distance were independently correlated with heart dose. Conclusions DIBH technique in WBI for left breast cancer after breast-conserving surgery significantly reduces heart and lung doses compared with FB. Changes in lung volume are the basis for improving the relative anatomical location of the heart. The heart-to-lung volume ratio and maximum heart margin distance may provide a reference for DIBH technique.

Effect of deep inspiration breath-hold technique on dosimetry of target volume and organs at risk in mediastinal lymphoma irradiation / 中华放射肿瘤学杂志

Objective Objective To evaluate the effect of deep inspiration breath-hold technique (DIBH) on the dosimetry of target volume and organs at risk (OARs) in mediastinal lymphoma irradiation.Methods This was a prospectively study and five patients with stage Ⅰ and Ⅱ mediastinal lymphomas were included continuously.The absolute target volume,the absolute OAR doses,and the relative doses to volume were compared between DIBH and free-breathing (FB) scans,based on the principles of the affected site irradiation and the butterfly field.The differences were analyzed using paired t test.Results The median age of these five patients was 30 years.Compared with FB scan,DIBH scan led to significant decreases in the gross tumor volume (GTV)(Δ=29.4 cm3,P=0.006) and the planning target volume (PTV)(Δ=322 cm3,P=0.005) before chemotherapy,while no significant difference in clinical target volume (CTV) was found.Meanwhile,the lung volume of DIBH scan was significantly increased (mean Δ=1456 cm3,P=0.001),while the heart width of DIBH scan was significantly reduced (Δ=1.3 cm,P=0.012),as compared with those of FB scan.The mean doses to the lung and heart were significantly lower in DIBH scan than in FB scan (heart:8.5±4.7 Gy vs.11.6±4.7 Gy,P=0.022;lung:7.6±1.1 Gy vs.11.6±1.4 Gy,P=0.000).The absolute target volume of the heart was significantly reduced at V15 and above in DIBH scan than in FB scan (all P<0.05).Relative doses to volume of the lung and heart were significantly reduced at each dose level (from V5 to V35) in DIBH scan than in FB scan (all P<0.05).Conclusions DIBH technique can significantly reduce PTV,enlarge lung volume,and reduce the mean dose and relative doses to volume of the lung and heart at each level (from V5 to V35) compared with FB scan in mediastinal lymphoma radiation.

Evaluation of the effect of deep inspiration breath-hold on radiation therapy for left breast cancer and the correlation between cardiac chest wall contact distance and cardiac exposure / 中国综合临床

Objective To compare the exposure to heart and other organs of the application of DIBH (deep inspiration breath-hold)and FB(free breath)in the left breast cancer radiotherapy,and the relationship between CCD(cardiac contact distance)and heart dose was analyzed.Methods Thirty patients with left breast cancer were examined with CT scans using DIBH and FB respectively,and then the dose was calculated by TPS(treatment planning system).The dose of heart,left anterior descending branch and left ventricle were analyzed by DVH(dose volume histogram).FB-CCDax(Axial cardiac chest wall contact distance)and FB-CCDps(sagittal heart chest wall contact distance)in CT images were measured based on FB.Results The parameters showed that,in radiotherapy with the application of DBIH technology,the irradiated volume of heart, left anterior descending branch(LAD),left ventricle(LV)of were significantly lower than that in the organs in the FB,the mean dose(Dmean)of heart of the former was 0.8 Gy,compared with 2.7 Gy in the latter one(P<0.005).The Dmean of LAD was 4.0Gy,compared with 12.7Gy in the latter one(P<0.001); The Dmean of LV was 1.2Gy,compared with 3.6Gy in the latter one(P<0.005).In the DIBH and FB radiotherapy,the Dmean of the heart,left anterior descending branch and left ventricle was correlated with FB-CCDps,but not with FB-CCDax.Conclusion DIBH is a simple treatment technique that can effectively reduce the cardiac radiation dose without loss of target dose.FB-CCDps is a potential predictor of cardiac exposure,and the longer the FB-CCDps distance is,the higher the cardiac dose is.The study found that at least 70% of patients with left breast cancer would benefit from DIBH and reduce the radiation exposure to normal cardiac structures,so DIBH should be used as a routine clinical application.

Application of deep inspiration breath hold in postoperative radiotherapy for left-side breast cancer / 中华放射医学与防护杂志

Objective To investigate the dosimetric differences among three types of breath hold mode ( free breath:FB, thoracic deep inspiration breath hold: T-DIBH, abdomen deep inspiration breath hold:A-DIBH) and to explore the optimal breath hold method in the postoperative radiotherapy of left-side breast cancer patients with minimum dose to normal tissues and organs at risk. Methods A total of eighteen patients with left-side breast cancer patients who underwent postoperative radiotherapy were enrolled in this study. Three CT simulation scans with three different breath hold method ( FB, T-DIBH, and A-DIBH ) were performed for each patient. Dosimetric differences were compared among plans generated on these three different CT image sets. Results There was no significant difference in the volume, mean dose, and homogeneity of planning target volume ( PTV) among plans generated from three different image sets (P>0. 05). The mean heart dose, mean LAD dose and mean ipsilateral lung dose in plans generated from CT image sets with FB, T-DIBH and A-DIBH were (3. 21 ± 1. 02), (1. 74 ± 0. 51), (1. 31 ±0. 41) Gy (W =171, P <0. 05), (34. 61 ± 13. 51), (14. 38 ±10. 20), (9. 21 ± 6. 53) Gy (W=171, P<0. 05), and (8. 31 ±2. 75), (7. 46 ±1. 96), (6. 89 ±1. 79) Gy (W=171, P<0. 05), respectively. Conclusions Compared with plans with FB, plans with DIBH ( T-DIBH and A-DIBH ) achieved lower cardiac, LAD and pulmonary doses. A-DIBH achieved a better normal dose reduction than T-DIBH.

The deep inspiration breath hold technique using Abches reduces cardiac dose in patients undergoing left-sided breast irradiation

PURPOSE: We explored whether the deep inspiration breath hold (DIBH) technique using Abches during left-sided breast irradiation was effective for minimizing the amount of radiation to the heart and lung compared to free breathing (FB). MATERIALS AND METHODS: Between February and July 2012, a total of 25 patients with left-sided breast cancer underwent two computed tomography scans each with the DIBH using Abches and using FB after breast-conserving surgery. The scans were retrospectively replanned using standardized criteria for the purpose of this study. The DIBH plans for each patient were compared with FB plans using dosimetric parameters. RESULTS: All patients were successfully treated with the DIBH technique using Abches. Significant differences were found between the DIBH and FB plans for mean heart dose (2.52 vs. 4.53 Gy), heart V30 (16.48 vs. 45.13 cm3), V20 (21.35 vs. 54.55 cm3), mean left anterior descending coronary artery (LAD) dose (16.01 vs. 26.26 Gy, all p < 0.001), and maximal dose to 0.2 cm3 of the LAD (41.65 vs. 47.27 Gy, p = 0.017). The mean left lung dose (7.53 vs. 8.03 Gy, p = 0.073) and lung V20 (14.63% vs. 15.72%, p = 0.060) of DIBH using Abches were not different significantly compared with FB. CONCLUSION: We report that the use of a DIBH technique using Abches in breathing adapted radiotherapy for left-sided breast cancer is easily feasible in daily practice and significantly reduces the radiation doses to the heart and LAD, therefore potentially reducing cardiac risk.

Airway Responses to Deep Inspiration in Asthma by Different Bronchial Challenge

OBJECTIVE: Deep inspirations (DI) provide physiologic protection against airway narrowing and DI-induced bronchoprotection and bronchodilation are impaired in asthma. METHODS: To evaluate effect of DI on airway narrowing during methacholine challenge, we compared the 2 minutes tidal breathing method and the breath dosimeter method. Methacholine challenge in 12 asthmatics and 10 healthy controls was cross-overly performed by two methods. On first visit, a questionnaire for symptoms, allergy skin test, spirometry, and methacholine challenge was performed. On second visit, spirometry and methacholine challenge using the 25 mg/mL at 5 minutes intervals during the 2 minutes tidal breathing method and the ten-breath dosimeter method were performed on two separate days at same time each day. RESULTS: The decreases in forced expiratory volume in one second (FEV1) and forced vital capacity during the 2 minutes tidal breathing method and dosimeter method in patients with asthmatics were higher than those in normal controls. The decreases in FEV1 and forced vital capacity during the 2 minutes tidal breathing method were higher than during dosimeter method in both asthmatics and controls. CONCLUSION: These observations indicate that the continuous generation method produce more bronchoconstriction than the dosimeter method during methacholine challenge and asthmatics had more bronchoconstriction than controls, suggesting inhibition of DI enhance methacholine induced airway narrowing in asthmatics.

Comparative study of the displacement of the selected clips in the cavity measured by orthogonal kilovoltage X-ray film in conditions of free breath and active breathing control for patients treated by external-beam partial breast irradiation / 中华放射肿瘤学杂志

Objective To compare the displacements of the clips in the cavity measured with orthagonal kilovoltage (KV) X-my plain film in conditions of moderate deep inspiration breathing hold(mDIBH) and free breath (FB), and compare the margins from clinical target volume (CTV) to planning target volume (PTV) based on the displacements. Methods Before radiotherapy, 2 and 5 sets of orthogonal KV plain film were respectively collected in mDIBH and FB group, then the automatic registration of the reconstructed KV plain film and DRR derived from the planning OF images was finished. In conditions of mDIBH and FB, the displacements of the selected clip at the same location in the different directions and of the different selected clips in the same direction were compared. The margins in three dimensional directions were calculated and compared in conditions of mDIBH and FB . Results In FB hold group, the difference of displacement in left-right (LR), cranial-caudal (CC) and anterior-posterior (AP) directions were statistically significant between the clips at the cranial and caudal border of the cavity (9. 7 mm and 10. 6 nun (Z = -2. 12,P =0. 037) ,7. 3 mm and 8. 3 mm (Z = -2. 31 ,P=0. 041) ,15.5 mm and 16. 1 nun (Z = -2. 32,P = 0. 041)), but not statistically significant for the clips at the bottom and lateral P=0.814),15.7 mm and 16.5 mm (Z=-0.26,P=0.856)). The corresponding differences in the different directions were statistically significant (5.0 mm and 7. 8 mm(Z = -2. 31, P =0. 036), 5.0 mm and 9. 3 nun (Z= -2. 21,P=0. 021),7. 8 mm and9.3 mm (Z= -2. 11,P=0.041)). In FB group, the differences of the displacements of the four selected clips were statistically significant in CC and AP directions (7.3 mm and 8.4 mm (Z= -2.45,P=0.021), 15.5 mm and 16.5 mm (Z= -2.41,P= 0.043)), but not in LF direction (10.6 nun and 10.6 mm (Z= -0.24,P=0. 815)). In mDIBH group, the displacements in LF direction were statistically significant (4. 4 mm and 5.4 mm (Z = -2. 31, P = O. 031)), but not in CC and AP directions (8. 6 mm and 8.6 mm (Z =-0. 21, P = 0. 815), 10. 5 mm and 10. 8 mm (Z = -0. 27 ,P =0. 754)). There were statistically significant difference of the margins in LF and AP directions (9.7 mm and 5.0 mm (Z= -2.34,P=0.029),15.5 mm and 9.3 mm (Z= -2. 31,P= 0.021)), but not in CC direction (7.3 mm and 7. 8 mm (Z= -0.29,P =0.770)) between mDIBH and FB conditions. Conclusions The margins extended from CTV to PTV for EBPBI should be determined based on the respiratory status, border location and border direction.

The effect of deep inspiration on methacholine induced bronchoconstriction / 천식및알레르기

BACKGROUND: Deep inspiration not only has a bronchodilatory effect but also a bronchopro- tective effect. We compared the 2-min tidal breathing method and the five-breath dosimeter method to evaluate effect of deep inspiration on airway narrowing during methacholine provocation tests (MPT) in normal subjects. METHODS: Eleven normal volunteers (seven males and four females) inhaled five doses of methacholine (25mg/ml) at 5-min intervals during the 2-min tidal breathing method and the five-breath dosimeter method. MPT was cross-overly performed by the two methods. On first visit, a questionnaire for symptoms, allergy skin test, spirometry, and MPT (2-min tidal breathing and five-breath dosimeter method) were performed. On second visit, pulmonary function tests and methacholine challenge using the 25mg/mL dose were performed on two separate days at the same time each day. The perception of dyspnea during methacholine challenge was scored using modified Borg scale. The recovery time from maximal decrease in FEV1 to baseline FEV1 was checked without using bronchodilator after MPT. RESULTS: The maximal decreases in FEV1 and FVC during the 2-min tidal breathing method were 38.8+/-5.3% and 27.8+/-5.1%, respectively. The maximal decreases in FEV1 and FVC during the five-breath dosimeter method were 16.5+/-6.1% and 14.2+/-4.9%, respectively. Score on Borg scale during the 2-min tidal breathing method at methacholine dose 1 was from 0.5 to 7. The FEV1 and FVC at methacholine dose 1, 2, 3, 4, 5 showed significantly greater decreases during the 2-min tidal breathing method compared to those during the five-breath dosimeter method. There was significant correlation between maximal decrease in FEV1 during the five-breath dosimeter method and recovery time from decrease in FEV1 to baseline FEV1 (r=0.82; p<0.01). A significant correlation (r=0.79; p<0.05) was found between decrease in FEV1 at methacholine dose 1 during the 2-min tidal breathing method and perception score. CONCLUSION: These observations indicate that the continuous generation method produces more bronchoconstriction than the dosimeter method for delivering methacholine aerosol during MPT, suggesting inhibition of deep inspiration enhances methacholine induced airway narro- wing in normal subjects.