Mean Lung Volume Research Articles

Role of adaptive radiotherapy during concomitant chemoradiotherapy for limited-stage small-cell lung cancer.

Tumor shrinkage is frequently observed during conventionally fractionated chemoradiotherapy for limited-stage small-cell lung cancer (SCLC). The specific goals of this study are to evaluate the gross tumor volume (GTV) changes due to treatment-induced tumor reduction during the course of radiotherapy (RT) and to examine its potential use in adaptive radiotherapy (ART) for tumor dose escalation or normal tissue sparing in patients with SCLC. A total of 10 patients with SCLC eligible for chemoradiotherapy underwent computed tomography (CT) scan after Fractions 13 and 23 (at nominal doses of 23.4 Gy and 41.4 Gy, respectively). The GTV was delineated on the repeat CT scans, and two treatment plans were generated with or without adaptation to tumor shrinkage during RT for each patient. Dosimetric and volumetric analyses were performed. The average GTV reduction observed over 13 fractions was 58.5% (range: 13.2%-92.3%; P < 0.001) and over 23 fractions was 70% (range: 36.9%-84.5%; P < 0.001). Compared with the plan without adaptation, ART resulted in mean lung dose relative decreases of 8.7%, mean lung volume receiving ≥20 Gy relative decreases of 5%, mean lung volume receiving ≥5Gy relative decreases of 10%, mean medulla spinalis dose relative decreases of 21 cGy, mean esophagus volume receiving ≥50 Gy relative decreases of 19%, and mean heart volume receiving ≥42 Gy relative decreases of 13%. The benefits of ART were the greatest for tumor volumes ≥30 cm3 and are directly dependent on GTV reduction during treatment. ART for SCLC achieved a significant benefit in terms of organ at risk (OAR) and dose escalation.

Evaluating Danish Breast Cancer Group locoregional radiotherapy guideline adherence in clinical treatment data 2008–2016: The DBCG RT Nation study

Background and purposeGuideline adherence in radiotherapy is crucial for maintaining treatment quality and consistency, particularly in non-trial patient settings where most treatments occur. The study aimed to assess the impact of guideline changes on treatment planning practices and compare manual registry data accuracy with treatment planning data. Materials and methodsThis study utilised the DBCG RT Nation cohort, a collection of breast cancer radiotherapy data in Denmark, to evaluate adherence to guidelines from 2008 to 2016. The cohort included 7448 high-risk breast cancer patients. National guideline changes included, fractionation, introduction of respiratory gating, irradiation of the internal mammary lymph nodes, use of the simultaneous integrated boost technique and inclusion of the Left Anterior Descending coronary artery in delineation practice. Methods for structure name mapping, laterality detection, detection of temporal changes in population mean lung volume, and dose evaluation were presented and applied. Manually registered treatment characteristic data was obtained from the Danish Breast Cancer Database for comparison. ResultsThe study found immediate and consistent adherence to guideline changes across Danish radiotherapy centres. Treatment practices before guideline implementation were documented and showed a variation among centres. Discrepancies between manual registry data and actual treatment planning data were as high as 10% for some measures. ConclusionNational guideline changes could be detected in the routine treatment data, with a high degree of compliance and short implementation time. Data extracted from treatment planning data files provides a more accurate and detailed characterisation of treatments and guideline adherence than medical register data.

Impact of Volume-Oriented Incentive Spirometry on Lung Volume and Peak Expiratory Flow Rate in Patients With Tracheostomy.

Background The volume-oriented incentive spirometer is a specialized device designed to facilitate maximal inspiration, promote deep breathing exercises, and enhance lung function. The use of spirometry is challenging and not proven in patients with tracheostomy. Therefore, this study aimed to assess the impact of volume-oriented incentive spirometry on lung volume and peak expiratory flow rate (PEFR) in patients with tracheostomy. Methodology All adult patients with cuffed tracheostomy tubes with a Medical Research Council (MRC) score of more than 48 were studied. Volume-oriented incentive spirometry was performed and the PEFR was measured before and after the spirometry session. All patients underwent 28 sessions in seven days with initial few training sessions. Patient demographic information, such as age, gender, reasons for tracheostomy, MRC at the beginning of the session, volume (volume per breath, mL), and PEFR, was documented. Results Thirty patients were studied, consisting of 18 males and 12 females with initial MRC scores ranging from 48 to 60. The mean lung volume and mean PEFR at the end of seven days were 950 ± 330.9and 134.7 ± 63.3, respectively, demonstrating safety with minimal complications, including four cases of pain at the tracheostomy site, three cases of hypotension, one case of abdominal pain, and 22 cases with no reported complications. Conclusion Volume-oriented incentive spirometry improves lung volumeand PEFRin patients with a tracheostomy tube. Additionally, spirometry proved to be both feasible and effective in this patient population.

Abstract 12928: Deep Learning-Derived Characterization of Lung Tissue Predicts Future Diagnosis of Heart Failure

Background: Cardiovascular and respiratory diseases are intrinsically coupled. Scalable methods for quantifying cardiac and pulmonary structures may improve our understanding of cardiopulmonary disease. Aims: We sought to quantify textural parameters of the lung fields in cardiovascular magnetic resonance imaging (cMRI) from the UK Biobank. We then sought to determine their genetic basis and their relationship with heart failure. Methods: We fine-tuned a convolutional neural network to segment left and right lung on cMRIs performed during expiratory breath hold. A random sample of 300 coronal slices from unique individuals was manually annotated for fine-tuning. The model was applied to 912,320 coronal cMRI images. Segmentation masks were stacked, and lung volume and texture metrics were quantified from the resulting 3D masks using the pyradiomics Python package. Results: After quality control, we computed lung traits in 45,179 participants. Mean lung volume was 2.19 ± 0.49 L in women and 2.87 ± 0.68 L in men. After adjustment for age and sex, lung volume was associated with forced vital capacity (FVC) (β = +0.30 L per SD, p &lt; 1.1 х 10 -308 ). After adjustment for age and sex, body size traits (e.g. standing height and heel bone mineral density) were associated with increased lung volume, whereas adiposity traits (e.g. body mass index and visceral adipose tissue) were associated with decreased lung volume. Greater heterogeneous and coarse lung textures were associated with an increased risk of heart failure (1-SD hazard ratios: 1.21 (95% CI [1.12, 1.31]) and 1.32 (95% CI [1.18, 1.47]), respectively). This association was still significant among non-smokers and after adjustment for left ventricular ejection fraction. Conclusions: Deep-learning derived measures of lung texture are linked to future heart failure. Our findings suggest that heart failure may manifest as changes in lung tissue that are detectable on MRI before changes in cardiac function.

Prediction of Acute Radiation-Induced Lung Toxicity After Stereotactic Body Radiation Therapy Using Dose-Volume Parameters From Functional Mapping on Gallium 68 Perfusion Positron Emission Tomography/Computed Tomography

The aim of this work was to compare anatomic and functional dose-volume parameters as predictors of acute radiation-induced lung toxicity (RILT) in patients with lung tumors treated with stereotactic body radiation therapy. Fifty-nine patients treated with stereotactic body radiation therapy were prospectively included. All patients underwent gallium 68 lung perfusion positron emission tomography (PET)/computed tomography (CT) imaging before treatment. Mean lung dose (MLD) and volumes receiving x Gy (VxGy, 5-30 Gy) were calculated in 5 lung volumes: the conventional anatomic volume (AV) delineated on CT images, 3 lung functional volumes (FVs) defined on lung perfusion PET imaging (FV50%, FV70%, and FV90%; ie, the minimal volume containing 50%, 70%, and 90% of the total activity within the AV), and a low FV (LFV; LFV = AV - FV90%). The primary endpoint of this analysis was grade ≥2 acute RILT at 3 months as assessed with National Cancer Institute Common Terminology Criteria for Adverse Events version 5. Dose-volume parameters in patients with and without acute RILT were compared. Receiver operating characteristic curves assessing the ability of dose-volume parameters to discriminate between patients with and without acute RILT were generated, and area under the curve (AUC) values were calculated. Of the 59 patients, 10 (17%) had grade ≥2 acute RILT. The MLD and the VxGy in the AV and LFV were not statistically different between patients with and without acute RILT (P > .05). All functional parameters were significantly higher in acute RILT patients (P < .05). AUC values (95% CI) for MLD AV, LFV, FV50%, FV70%, and FV90% were 0.66 (0.46-0.85), 0.60 (0.39-0.80), 0.77 (0.63-0.91), 0.77 (0.64-0.91), and 0.75 (0.58-0.91), respectively. AUC values for V20Gy AV, LFV, FV50%, FV70%, and FV90% were 0.65 (0.44-0.87), 0.64 (0.46-0.83), 0.82 (0.69-0.95), 0.81 (0.67-0.96), and 0.75 (0.57-0.94), respectively. The predictive value of PET perfusion-based functional parameters outperforms the standard CT-based dose-volume parameters for the risk of grade ≥2 acute RILT. Functional parameters could be useful for guiding radiation therapy planning and reducing the risk of acute RILT.

Can lung semi-quantitative measurements and mediastinal adipose tissue volume predict prognosis in patients with idiopathic pulmonary fibrosis (IPF)? A CT-based preliminary study.

The aim of this study was to assess the potential of subcutaneous adipose tissue volume, mediastinal adipose tissue volume, lung density, and lung volume (as measured on high-resolution computed tomography) to predict disease progression in patients with idiopathic pulmonary fibrosis (IPF). Additionally, the study aimed to evaluate the changes in these semiquantitative measures over time. The HRCT images of 57 patients diagnosed with IPF were retrospectively screened. Subcutaneous adipose tissue volume, mediastinal adipose tissue volume, and mean lung density and volume were measured at the time of diagnosis and at the 12th month. The ability of these parameters to predict progression was evaluated using the univariate and multivariate Cox regression analyses. Low mediastinal adipose tissue volume at diagnosis had a 0.991-fold effect [odds ratio (OR)= 0.991, 95% confidence interval (CI)= 0.984-0.997, p< 0.001] on progression. Low mediastinal adipose tissue volume at diagnosis had a 0.993-fold effect [odds ratio (OR)= 0.993, 95% confidence interval (CI)= 0.975-1.011, p< 0.001] and progression development at the 12th month had a 6.5-fold effect [odds ratio (OR)= 6.516, 95% confidence interval (CI)= 1.594-26.639, p< 0.009] on mortality. This study indicate that the prognosis was better in those with a large mediastinal adipose tissue volume among the patients with IPF.

Dosimetric and Patient Preference Analysis between 4-Dimension CT (4D CT) Scan and Deep Inspiration Breath Holding (DIBH) for SBRT in Lung Tumors

<h3>Purpose/Objective(s)</h3> Stereotactic body radiation therapy (SBRT) for early lung tumors and oligometastasis in the lung is a proven treatment technique. Motion management plays an essential role in very accurate treatment delivery. Among the various techniques available, the most widely implemented are Deep Inspiration Breath holding (DIBH) and 4 Dimensional CT (4DCT) scan. This study aims to compare the techniques mentioned above dosimetrically and according to patient preferences. This analysis would let us know the better motion management technique for each patient <h3>Materials/Methods</h3> All eligible patients for SBRT of lung treatment undergo both DIBH and 4D CT scans planning images. Contouring and planning are done on both these sets of images, and based on the dosimetric profile and patient preference, select the appropriate treatment. We retrospectively analyzed the initial five patients who were treated with SBRT for lung. All these patients underwent CT simulation using 4D CT and DIBH techniques. For the 4D CT, Maximum intensity projection (MIP) images were created, and contouring was done on these images. Planning Target Volume (PTV) was created, and planning was done on treatment planning system planning software. 6MV FFF beam (Dose rate of 1400MU/min) using Volumetric Modulated Arc Therapy (VMAT) technique was used for planning. The dose to the target volume was kept uniform and doses to normal tissue were noted for both the plans <h3>Results</h3> The dose to the PTV was 54 Gy in 3 fractions, and all were able to adapt to the deep breath-hold technique. With the DIBH increased lung volume, the mean right lung and left lung volumes were 1848.4 cc and 1636.2 cc, respectively, 1.49 times and 1.64 times more than the mean right lung (1237.5 cc) and left lung (993.46 cc) on 4D CT respectively. The mean GTV on DIBH was 30.62 cc, and that on 4D CT was 37.21 cc. This 4D CT GTV, in effect, was nearly 1.2 times more in volume than DIBH. The mean dose of the ipsilateral lung on DIBH was 5.35 Gy, and on 4D CT, it was 6.16 Gy, which is 1.15 times more than DIBH, both well within the tolerance limits of the lung. The Conformity index (CI) and homogeneity index (HI) for both the plans were similar. The dose to other normal tissue was the same for both plans. Peripheral lesions that are adherent to pleura GTV/ ITVs are almost the same in both DIBH and 4D CT <h3>Conclusion</h3> The volume of GTV was slightly lesser in DIBH because of the breath-holding. But for peripheral tumors (metastasis), which are adherent to pleura, given decreased movements of GTV/ ITV, are almost the same in both DIBH and 4D CT. The mean dose to the ipsilateral lung is less in DIBH than 4D CT. The analysis shows that SBRT in DIBH and 4D CT is an equally good technique with a dose to the normal tissues well within normal limits and can be individualized according to the patient's comfort and location of the tumor, with an overall preference for the DIBH technique

Deep inspiratory breath hold assisted by continuous positive airway pressure ventilation for lung stereotactic body radiotherapy

PurposeContinuous positive airway pressure (CPAP) ventilation hyperinflates the lungs and reduces diaphragmatic motion. We hypothesized that CPAP could be safely combined with deep inspiratory breath hold (CPAP-DIBH) during lung stereotactic radiotherapy (SBRT). Material and methodsPatients with stage-1 lung cancer or lung metastasis treated with CPAP-DIBH SBRT between 3/2017–5/2021 were analyzed retrospectively. Patient characteristics, treatment parameters, duration of breath holds in all sessions and tolerance to CPAP-DIBH were recorded. Local control (LC) was assessed from CT or PET-CT imaging. The distances between the tumor and mediastinal organs at risk (OAR) in centrally located tumors using either free breathing (FB) or CPAP-DIBH were compared. Toxicity was graded retrospectively. ResultsForty-five patients with 71 lesions were treated with CPAP-DIBH SBRT. Indications for CPAP-DIBH were prior radiation (35/71, 65%), lower lobe location (34/71, 48%), multiple lesions (26/71, 36.6%) and proximity to mediastinal OAR (7/71, 10%). Patient characteristics were: F:M 43%: 57%; mean gross tumor volume 4.5cm3 (SD 7.9), mean planning target volume 20cm3 (SD 27), primary: metastatic lesions (7%:93%). Mean radiation dose was 52.5 Gray (SD3.5). Mean lung volume was 5292cm3 (SD 1106). Mean duration of CPAP-DIBH was 41.3s (IQR 31–46.8). LC at 2 years was 89.5% (95% CI 76–95.5). In patients with central lesions, the distance between the tumor and mediastinal OAR increased from 0.84cm (SD 0.65) with FB to 1.23cm (SD 0.8) with CPAP-DIBH (p=0.002). Most patients tolerated CPAP well and completed all treatments after starting therapy. Three patients did not receive treatment: 2 were unable to tolerate CPAP and 1 had syncope (pre-existing). Toxicity was grade 2 in 4/65 (6%) and grade 3 in 1/65 (1.5%). There was no grade 2 or higher esophageal or tracheal toxicities. ConclusionCPAP-DIBH assisted lung SBRT was tolerated well and was associated with minimal toxicity and favorable LC. This technique may be considered when treating multiple lung lesions, lesions located in the lower lobes or adjacent to mediastinal OAR.

Quantitative Evaluation of Chronic Obstructive Pulmonary Disease and Risk Prediction of Acute Exacerbation by High-Resolution Computed Tomography.

Objective It is imperative to popularize the tertiary prevention of chronic obstructive pulmonary disease (COPD) and to improve the diagnosis and treatment. Methods COPD patients were divided into mild (n = 18), moderate (n = 20), severe (n = 24), and extremely severe (n = 22) groups for performing high-resolution computed tomography (HRCT) and pulmonary function test. Serum procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) were detected, and the occurrence rate of acute exacerbation COPD (AECOPD) was recorded during a 12-months follow-up period. Results With an increase in the severity grade, the HRCT indexes, including emphysema index (EI), 1st and 15th percentile of inspiratory attenuation distribution (Perc1 and Perc15), ratio of expiratory/inspiratory mean lung density (MLDex/in) and lung volume (LVex/in), and ratio of the wall thickness to the outer diameter of the lumen (TDR), as well as percentage of the wall area to the total cross-sectional area (WA%) were increased with a decreased change in relative lung volume with attenuation values between −860 and −950 HU (RVC−860to −950) and lumen area (Ai). These were correlated with the ratio of forced expiratory volume in 1 sec (FEV1) over forced vital capacity (FVC) (FEV1/FVC), the percentage of FEV1 the predicted value (FEV1%), and ratio of residual volume to total lung volume (RV/TLC). Body mass index, MLDex/in, FEV1%, FEV1/FVC, and PCT had a predictive value to AECOPD, with the combined AUC of 0.812. Conclusions HRCT imaging effectively classifies the severity of COPD, which combined with BMI, PFT, and serum PCT can predict the risk of AECOPD.

Examination of the dose distribution of volumetric modulated arc radiotherapy using a high-definition multi-leaf collimator for breast cancer patients with irradiated regional lymph nodes.

BackgroundA high-definition multi-leaf collimator (HD-MLC) with 5- and 10-mm fine MLCs is useful for radiotherapy. However, it is difficult to irradiate the mammary gland and supraclavicular region using a HD-MLC because of the narrow field of volumetric modulated arc radiotherapy (VMAT). Therefore, we aimed to evaluate the dose distribution of the VMAT dose using a HD-MLC in 15 patients with left breast cancer undergoing postoperative irradiation of breast and regional lymph nodes, including the internal mammary node.Materials and methodsThe following four plans were generated: three-arc VMAT using HD-MLC (HD-VMAT), two tangential arcs and one-arc VMAT using HD-MLC (tHD-VMAT), three-dimensional conformal radiotherapy (3DCRT) using HD-MLC, and two-arc VMAT using the Millennium 120-leaf MLC (M-VMAT). We assessed the doses to the target volume and organs at risk.ResultsThe target dose distributions were higher for HD-VMAT than 3DCRT. There were no significant differences in the heart mean dose (Dmean) or lung volume receiving 20 Gy (V20 Gy) between HD-VMAT and 3DCRT. The heart Dmean and lung V20 Gy of tHD-VMAT were higher than those of HD-VMAT, and the heart Dmean of M-VMAT was higher than that of HD-VMAT. However, the target doses of tHD-VMAT, M-VMAT, and HD-VMAT were equivalent.ConclusionsIn cases of the mammary gland and regional lymph node irradiation, including the internal mammary node in patients with left breast cancer, HD-VMAT was not inferior to M-VMAT and provided a better dose distribution to the target volume and organs at risk compared with 3DCRT and tHD-VMAT.

Neuroendocrine cell hyperplasia of infancy: Feasibility of objective evaluation with quantitative CT

ObjectiveTo describe quantitative CT parameters of children with a typical pattern for NEHI and compare them to controls. Materials and methodsEleven patients (7 boys) with NEHI and an available chest CT concordant NEHI were identified. Eleven age-, sex-, height-matched, with CT technique-matching were identified for comparison. An open-source software was used to segment the lung parenchyma into lobes using the fissures. Quantitative parameters such as low attenuation areas, mean lung density, kurtosis, skewness, ventilation heterogeneity, lung mass, and volume were calculated for both controls and cases. ResultsAnalysis of the lung parenchyma showed that patients with NEHI had a lower mean lung density (−615 HU vs −556 HU, p = 0.03) with higher ventilation heterogeneity (0.23 vs 0.19, p = 0.04), lung mass (232 g vs 146 g, p = 0.01) and volume (595 mL vs 339 mL, p = 0.008) compared to controls. Most lobes followed this trend, except the middle lobe that showed only a higher lung mass (32.9 g vs 19.6 g, p = 0.02) and volume (77.4 vs 46.9, p = 0.005) in patients with NEHI compared to controls. ConclusionQuantitative CT is a feasible technique in children with a typical pattern for NEHI and is associated with differences in attenuation, ventilation heterogeneity, and lung volume.

Perinatal outcome of fetal pulmonary pathology in relation to pulmonary volume measured with nuclear magnetic resonance

Introduction: The prognosis in fetal lung disease is related to the size of the pulmonary malformation and secondary pulmonary hypoplasia. The mass effect on the underlying fetal lung results in a decrease in fetal lung volume and an increased likelihood of developing respiratory distress during the neonatal period. Objectives: Estimate the lung volume cut-off points related to neonatal morbidity and mortality in fetuses with congenital pulmonary malformation measured through magnetic resonance imaging. Methodology: Analytical retrospective cohort study from July 1, 2013, to June 30, 2017. Lung volumes were measured by magnetic resonance imaging in fetuses with congenital pulmonary malformation. The different measures are described and the association of lung volume with neonatal mortality is evaluated. Results: We analyzed 26 fetuses with congenital pulmonary malformation. The mortality described was 46.1% (12/26). The mean lung volume in the group with mortality was 19.7cm3 (95% CI 12.1-27.3), vs 58.6cm3 in the group without mortality (95% CI 39.0-78.1) (p=0.0010). Average lung volumes less than 34.9 cm3 were associated with higher mortality. Conclusion: The perinatal result of fetal lung disease is related to lung volume measured with Fetal Magnetic Resonance Imaging, finding that lung volumes less than 34.9cm3 were associated with higher mortality.

Data-driven gated CT: An automated respiratory gating method to enable data-driven gated PET/CT.

The accuracy of positron emission tomography (PET) quantification and localization can be compromised if a misregistered computed tomography (CT) is used for attenuation correction (AC) in PET/CT. As data-driven gating (DDG) continues to grow in clinical use, these issues are becoming more relevant with respect to solutions for gated CT. In this work, a new automated DDG CT method was developed to provide average CT and DDG CT for AC of PET and DDG PET, respectively. An automatic DDG CT was developed to provide the end-expiratory (EE) and end-inspiratory (EI) phases of images from low-dose cine CT images, with all phases being averaged to generate an average CT. The respiratory phases of EE and EI were determined according to lung region Hounsfield unit (HU) values and body outline contours. The average CT was used for AC of baseline PET and DDG CT at EE phase was used for AC of DDG PET at the quiescent or EE phase. The EI and EE phases obtained with DDG CT were used for assessing the magnitude of respiratory motion. The proposed DDG CT was compared to two commercial CT gating methods: (1) 4D CT (external device based) and (2) D4D CT (DDG based) in 38 patient datasets with respect to respiratory phase image selection, lung HU, lung volume, and image artifacts. In a separate set of twenty consecutive PET/CT studies containing a mix of 18 F-FDG, 68 Ga-Dotatate, and 64 Cu-Dotatate scans, the proposed DDG CT was compared with D4D CT for impacts on registration and quantification in DDG PET/CT. In the EE phase, the images selected by DDG CT and 4D CT were identical 62.5% ± 21.6% of the time, whereas DDG CT and D4D CT were 6.5% ± 9.7%, and 4D CT and D4D CT were 8.6% ± 12.2%. These differences in EE phase image selection were significant (p < 0.0001). In the EI phase, the images selected by DDG CT and 4D CT were identical 68.2% ± 18.9% of the time, DDG CT and D4D CT were 63.9% ± 18.8%, and 4D CT and D4D CT were 61.2% ± 19.8%. These differences were not significant. The mean lung HU and volumes were not statistically different (p > 0.1) among the three methods. In some studies, DDG CT was better than D4D or 4D CT in the appropriate selection of the EE and EI phases, and D4D CT was found to reverse the EE and EI phases or not select the correct images by visual inspection. A statistically significant improvement of DDG CT over D4D CT for AC of DDG PET was also demonstrated with PET quantification analysis. When irregular breath cycles were present in the cine CT, DDG CT could be used to replace average CT for the improved AC of baseline PET. A new automatic DDG CT was developed to tackle the issues of misregistration and tumor motion in PET/CT imaging. DDG CT was significantly more consistent than D4D CT in selecting the EE phase images as the clinical standard of 4D CT. When compared to both commercial gated CT methods of 4D CT and D4D CT, DDG CT appeared to be more robust in the lower lung and upper diaphragm regions where misregistration and tumor motion often occur. DDG CT offered improved AC for DDG PET relative to D4D CT. In cases with irregular respiratory motion, DDG CT improved AC over average CT for baseline PET. The new DDG CT provides the benefits of 4D CT without the need for external device gating.

Dosimetric Analysis of Axillary Lymph Node Coverage Using High Tangents in the Prone Position for Left-Sided Breast Cancers.

Aim/Objective: Prone positioning is often used to reduce the dose to organs at risk during adjuvant breast irradiation. High tangents are used with supine treatments in patients with the low-volume nodal disease to increase nodal coverage while minimizing toxicities. Our study aims to evaluate nodal coverage for patients treated in the prone position with high tangents.Materials and Methods: Our study analyzed the plans for 20 patients with early-stage, left-sided breast cancers treated at our institution from 2018 to 2019. All patients were treated in the prone position. Axillary nodal levels I-III were contoured, and treatment plans were generated using high tangents. The heart, bilateral lungs, and breast tissue were retrospectively contoured. All plans were evaluated to a dose of 42.4 Gy in 16 fractions.Results: Level I lymph node levels had a mean coverage of 99% of the prescription dose (range: 98-100%). Similarly, level II coverage was approximately 88% (range: 65-100%). The mean coverage for level III was approximately 25% (range: 0-52%). The mean heart dose, mean lung volume receiving ≥20 Gy (V20) for the bilateral lungs, and ipsilateral V20 were 1.69 Gy, 1.64%, and 3.56%, respectively.Conclusion:Treating patients in the prone position with high tangents provides excellent coverage of axillary levels I and II, although there is minimal coverage of axillary level III. Prospective trials are needed to evaluate the clinical outcomes when treating patients with high tangents in the prone position.

Comparison of Continuous Thoracic Epidural With Erector Spinae Block for Postoperative Analgesia in Adult Living Donor Hepatectomy.

Background: Thoracic epidural analgesia (TEA) is commonly used for pain management in donor hepatectomy. Erector spinae plane block (ESPB) is a newer ultrasound-guided block described for the management of thoracic and abdominal pain. There is limited literature available comparing the two techniques. The objective of this study was to compare the postoperative analgesic efficacy and adverse effects of continuous ESPB to continuous TEA in donor hepatectomy.Methodology: The randomized controlled trial (RCT) was registered on ClinicalTrials.gov (NCT04151511). A total of 82 patients undergoing donor hepatectomy between January 2020 and December 2020 were recruited, of whom 41 received TEA and 41 received ESPB. Randomization was done by the sealed opaque envelope method.Results: The mean visual analog scale (VAS) scores in donors who received TEA and ESPB in post-anesthesia care unit (PACU) (2.7 + 0.9 vs. 2.4 + 0.5; P = 0.02) at one hour (2.7 + 0.9 vs. 2.2 + 0.6; P = 0.008), six hours (1.8 + 0.9 vs. 0.8 + 0.5; P < 0.001), 12 hours (0.9 + 0.7 vs. 0.2 + 0.7; P < 0.001), and 24 hours (0.48 + 0.5 vs. 0.08 + 0.3; P < 0.001) were significantly different. Mean opioid consumption was 3.38 ± 6.24 mg in the ESPB group and 10.75 ± 9.64 mg in the TEA group (P < 0.001). Mean lung volume (MLV) at 24 hours in the TEA group and ESPB group was 1543 ml and 1815 ml (P < 0.001). MLV was 2545 ml in the TEA group and 2820 ml in the ESPB group at 48 hours (P < 0.001). Mean nausea and vomiting score at six hours was 0.1 vs. 0.03 (P = 0.02).Conclusion: ESPB improves pain control after donor hepatectomy with an enhanced safety profile and reduced opioid consumption.

Work-related allergy and asthma associated with cleaning agents in health workers in Southern African tertiary hospitals.

Health workers (HWs) are exposed to diverse cleaning agents in large hospitals. This study determined the prevalence of work-related symptoms, allergic sensitization, and lung function abnormalities in HWs of two tertiary hospitals in Southern Africa. A cross-sectional study of 699 HWs (South Africa: SAH, n = 346; Tanzania: TAH, n = 353) was conducted. Health outcomes were assessed using a standardized ECRHS questionnaire, immunological tests (specific IgE antibody to common aero-allergens and to occupational allergens: natural rubber latex [NRL] Hev b5 and Hev b6.02, chlorhexidine, and ortho-phthalaldehyde [OPA]), spirometry [pre-and post- bronchodilator], methacholine challenge, and fractional exhaled nitric oxide (FeNO). A large proportion of participants (78%) were women. Median age was 42 years, with 76% nurses, 12% cleaners, and 5% administrative workers. Current smoking was more common in SAHWs (12%) than TAHWs (1%). The overall prevalence of doctor-diagnosed asthma was 7%. Atopy was present in 43% of HWs, while 4% were sensitized to OPA, 2% to NRL, and 1% to chlorhexidine. Prevalence of work-related ocular-nasal symptoms (16%) was higher than skin (12%) and chest (7%) symptoms. TAHWs had significantly lower mean lung volumes, higher degrees of significant airflow obstruction and impaired lung function. The prevalence of bronchial hyperresponsiveness in SAHWs (14%) was high. Overall, 23% of HWs had abnormal FeNO; 6% having high (>50 ppb) levels. FeNO was positively associated with sensitization to occupational allergens, primarily OPA and NRL. HWs from both hospitals had similar prevalence of work-related respiratory symptoms. Sensitization to OPA and NRL appears to be contributing to allergic airway inflammation in these HWs.

Initial estimates of continuous positive airway pressure (CPAP) on heart volume, position and motion in patients receiving chest radiation.

To evaluate effects of Continuous Positive Airway Pressure (CPAP)on cardiac position, volume, and motion in a cohort of patients receiving thoracic radiation therapy (RT). Patients underwent 3-dimensional (3D) and 4D-computerized tomography (CT) imaging with free-breathing (FB) and CPAP for RT planning. All scans were co-registered on the treatment planning system for contouring, identification of the center of heart volume and comparative measurements of cardiac displacement, volume and motion. Heart volume (HV) was created from 3D-CT contours. Range of heart motion was estimated by creating an internal heart volume (IHV) from 4D-CT contours. Magnitude of cardiac motion (cardiac excursion) was recorded as the difference in volume between IHV and HV. Wilcoxon signed rank test and Spearmen's rank correlation coefficient were used to assess differences between variables and correlations between lung volume and heart parameters. Results from 9 patient data sets were available for this report. Compared to FB, CPAP use was associated with caudal displacement of the HV (1 cm, p < 0.008) and IHV (1.1 cm, p < 0.008). CPAP use decreased HV 6% (p < 0.008) and IHV 13% (p < 0.008). Cardiac excursion was 49% (p < 0.01) less with CPAP than with FB. CPAP use increased mean lung volume by 30% (p < 0.008) which correlated with caudal displacement of the HV (r = 0.83, p < 0.008) and IHV (r = 0.98, p < 0.001). The use of CPAP reduced cardiac motion and volume although the reduction in volume was minimal. The increase in lung volume correlated with caudal displacement of the heart. These results suggest the mechanism for achieving dosimetric benefit was obtained by cardiac displacement and decreased lung and heart motion rather than reduction of HV. Further evaluation of CPAP as a novel technique to reduce heart exposure when offering RT is warranted.

Late-Onset, Noninfectious Pulmonary Complications following Allogeneic Hematopoietic Stem Cell Transplantation: A Nationwide Cohort Study of Long-Term Survivors

Background: Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for pulmonary adverse events. Data on late-onset noninfectious pulmonary complications in long-term adult survivors of allo-HSCT are limited and incomplete. Objectives: This study aimed (1) to determine occurrence and degree of pulmonary sequelae in adult survivors of allo-HSCT and (2) to identify associations between pulmonary function, high-resolution CT (HRCT), and clinical characteristics. Method: In a nationwide, single-center cross-sectional study, 103 survivors (aged median [range] 35 [17–58] years, 53% females) were examined 17 (6–32) years after allo-HSCT and compared with healthy controls (n = 105). Methods included pulmonary function tests and HRCT. Results: Chronic graft-versus-host disease was diagnosed in 33% of survivors, including 12% with bronchiolitis obliterans syndrome (BOS). Mean lung volumes (TLC, FVC, and FEV₁) and gas diffusing capacity were >80% of predicted for the survivors as a group, but significantly lower than in healthy controls. Pathological HRCT findings were detected in 48% of the survivors (71% airways disease, 35% interstitial lung disease, and 24% apical subpleural interstitial thickening). Air trapping (%) on HRCT correlated with % predicted FEV₁, p < 0.001. In a multiple logistic regression model, both BOS and pathological findings on HRCT were associated with chemotherapy prior to allo-HSCT, p < 0.05. Conclusions: Long-term allo-HSCT survivors had significantly lower pulmonary function than age- and gender-matched healthy controls and nearly half had pathological findings on HRCT. Longitudinal data will determine if pulmonary sequelae will remain stable or progress. We recommend lifelong monitoring of pulmonary function in allo-HSCT survivors. HRCT provides additional information, but is not suited for surveillance.

POS0842 LUNG ULTRASOUND TO ASSESS THE SEVERITY OF INTERSTITIAL LUNG DISEASE IN SYSTEMIC SCLEROSIS

Background:Interstitial lung disease (ILD) is one of the most common complications and one of the main causes of morbidity and mortality in Systemic Sclerosis (SSc). High-resolution computed tomography (HRCT) is the gold standard for the diagnosis of ILD and it allows its quantification. Among semi-quantitative methods, Goh et al proposed a semi-quantitative scoring system to visually quantify ILD extent, with categorical cut-off of 20% to distinguish limited and extensive parenchymal involvement with prognostic implications. More recently, the use of radiomics has allowed the objective quantification of ILD through the use of dedicated software, which calculate different parameters of lung density.Given the exposure to ionizing radiation that the procedure entails, other methods of ILD evaluation are being studied, among which lung ultrasound (LUS) identifies the B-lines as a main feature of ILD. So far, different evidences have proposed the use of LUS for the screening of ILD, even in the early phases of the disease and in subclinical lung involvement.Objectives:the aim of this study is to test the role of LUS in quantifying the severity of SSc-ILD, evaluated with both semi-quantitative visual radiological and quantitative radiomic scores.Methods:Adult SSc patients classified according to the ACR/EULAR 2013 criteria patients were assessed with pulmonary function test (PFTs), lung ultrasound and HRCT over 60 days. CT images were analysed qualitatively (by presence/absence of ILD), semi-quantitatively (categorical Goh score &lt;20% vs&gt; 20% of extent and the continuous extent Goh score made from 5 levels’ assessment– 0 to 100%) and quantitatively [with the densitometric radiomic data obtained through the Horos software - Mean lung attenuation (MLA), Standard Deviation (SD), Kurtosis, Skewness and Lung volume (LV)]. LUS was used to quantify the B-lines detected in each patient by scanning a total of 13 intercostal spaces, on both anterior and posterior chest wall.Results:Among 59 SSc patients (81% women, mean age 48±14 years, 45% anti-Scl70 positive), 23 (39%) presented ILD on HRCT, of which 14 limited and 9 extensive. The mean visual semi-quantitative score was 6%, ranging from 0 to 66%. Our data showed a significantly different number of B-Lines in ILD vs non-ILD patients (median 38 vs 9, p &lt;.005), a result which was further confirmed among non-ILD vs ILD&gt; 20% (median 47 vs 9, p=.001) and ILD &lt;20% (median 36 vs 9, p=.001) patients. Conversely, the number of B-lines was not statistically different between patients with ILD &lt;20% and &gt;20% (median 47 vs 36, p=.78). We observed a significant negative correlation between the number of B-lines and FVC (r=-.472, p&lt;.05) TLC (r=-.436, p=.003), DLco (r=-.515, p&lt;.001), DLCO/VA (r=.-306, p=.03). Finally, the number of B-lines showed a statistically significant correlation with the Goh score on 5 levels (r=.437, p=.001), MLA (r=.571, p&lt;.001), kurtosis (r=-.285, p=.028), skewness (r=-.370, p = .004) and LV (r=-.277, p=.033). All data were confirmed analysing anterior and posterior B-Lines separately.Conclusion:Our study confirms that LUS represents a useful tool for the identification of SSc-ILD. In addition, we showed that LUS may be useful also for the quantification of the severity of SSc-ILD, by correlating with PFT parameters, radiomics parameters and visual radiological evaluation. Together with the PFTs, LUS could be used to increase the accuracy of the screening and, potentially, of the follow-up of SSc-ILD patients.Disclosure of Interests:Cosimo Bruni: None declared, Lavinia Mattolini: None declared, Lorenzo Tofani: None declared, Luna Gargani Consultant of: GE Healthcare, Philips Healthcare and Caption Health, Nicholas Landini: None declared, Gemma Lepri: None declared, Martina Orlandi: None declared, Serena Guiducci: None declared, Silvia Bellando Randone: None declared, Marco Matucci-Cerinic: None declared

POS0322 CORRELATION BETWEEN QUANTITATIVE COMPUTED TOMOGRAPHY AND DISEASE ACTIVITY IN SYSTEMIC SCLEROSIS

Background:High Resolution Computed Tomography (HRCT) is the gold standard to evaluate Interstitial Lung Diseases (ILDs) extent and severity. Quantitative Computed Tomography (QCT) is a promising tool as it provides an operator-independent assessment of ILD extent. Even if there are emerging data on QCT in Systemic Sclerosis (SSc), its correlation with disease activity (DA) has not been yet studied.Objectives:To evaluate the correlation between QCT score and DA in an Italian cohort of SSc patients.Methods:A multicentric, observational study was conducted in three Italian rheumatological centers.Adult SSc patients classified according to the ACR/EULAR 2013 criteria [1] were assessed with pulmonary function tests, HRCT and for DA. CT images were analyzed quantitatively with the densitometric radiomic data obtained through a free open software – Mean lung attenuation (MLA), Standard Deviation (SD), Kurtosis, Skewness and Lung volume. DA assessment was conducted according to EUSTAR index [2]: a score ≥2.5 was considered indicative of high disease activity.Age below 18 and pregnancy were considered exclusion criteria. We used Student’s T test to evaluate the means of the parameters, Pearson’s r test for correlations, receiver operating characteristics curve to define the cutoff values of the significant details, and linear regression with collinearity test to define the role of the details. P value &lt;0.05 was considered statistically significant.Results:Sixty patients were enrolled (male 8, female 52), with mean age 53.2 years (SD 15.6) and mean disease duration 5.3 years (SD 4.2). QCT indexes distribution was different in high DA vs low DA SSc patients. In particular mean lung attenuation (MLA, -834.7 vs -812.1, p =0.03), standard deviation (95.9 vs 102, p =0.03), skewness (2.2 vs 1.7, P =0.006) and kurtosis (5.5 vs 3.3, p =0.009) of the parenchymal lung and skewness (3.1 vs 2.8, p =0.03) of the whole lung were statistically different. DA correlates with MLA (r =0.28, p =0.003), standard deviation (r =0.21, p =0.02), skewness (r =-0.32, p =0.001) and kurtosis (r =-0.29, p =0.001) of the parenchymal lung and MLA (r =0.25, p =0.006), skewness (R =-0.27, p =0.003), kurtosis (r =-0.21, P =0.02) of the whole lung. The skewness of the parenchymal lung was the QCT index with the best performance in identifying high DA SSc patients (cutoff value ≤1.85; area under the curve 0.74, p =0.005; sensitivity 79.5%, specificity 68.7% accuracy 76.6%).Conclusion:To our knowledge, this is the first study which correlate the QCT score with DA in SSc patients. Our results suggest that QCT can identify SSc patients with high DA score. This could open a scenario of new applications as an operator-independent contribution in DA scores with a potential role in clinical practice. Further studies are needed to confirm the data and to better identify the most suitable parameters for the purpose.