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S. Lam
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MO11 - Screening and Epidemiology (ID 131)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Imaging, Staging & Screening
- Presentations: 1
- Moderators:P. Zimmerman, J. Bowden
- Coordinates: 10/28/2013, 16:15 - 17:45, Bayside 201 - 203, Level 2
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MO11.14 - DISCUSSANT (ID 3995)
17:25 - 17:35 | Author(s): S. Lam
- Abstract
- Presentation
Abstract not provided
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O05 - Cancer Control (ID 130)
- Event: WCLC 2013
- Type: Oral Abstract Session
- Track: Prevention & Epidemiology
- Presentations: 1
- Moderators:N. Van Zandwijk, A. McWilliams
- Coordinates: 10/28/2013, 10:30 - 12:00, Bayside Auditorium A, Level 1
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O05.04 - DISCUSSANT (ID 3991)
11:00 - 11:15 | Author(s): S. Lam
- Abstract
- Presentation
Abstract not provided
Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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P2.20 - Poster Session 2 - Early Detection and Screening (ID 173)
- Event: WCLC 2013
- Type: Poster Session
- Track: Imaging, Staging & Screening
- Presentations: 1
- Moderators:
- Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
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P2.20-010 - Raman Spectroscopy Based Breath Analysis with Potential for Lung Cancer Detection (ID 3395)
09:30 - 09:30 | Author(s): S. Lam
- Abstract
Background
Lung cancer is the top cancer killer in North America and worldwide. Current lung cancer detection tools involving X-ray, CT and bronchoscopy are relatively time-consuming and costly. Breath analyses done by mass spectrometry have shown that certain endogenous volatile organic compounds (VOCs) are related to lung cancer and revealed the potential of breath analysis for lung cancer detection. But mass spectrometry is costly and has slow turnaround times. In another interesting development, electronic noses were made for breath analysis, however the signals generated from semiconductor array cannot accurately quantify nor correlate with VOCs. Raman spectroscopy is a promising candidate for breath analysis because it can offer unique fingerprint-type signals for molecular identification. Our objective is to develop a simple, cost-effective and non-invasive tool based on Raman spectroscopy for breath analysis and potentially for lung cancer screening.Methods
A Raman-gas analyzer was designed and built, based on photonic technologies. We employed a hollow core-photonic crystal fibre (HC-PCF), a novel light guide that allows light to be guided in a small hollow core and it can be filled with a gaseous sample (i.e., human breath) for spectral analysis. A gas supply system was built to provide a sealed environment for the loading and unloading of gaseous samples. A 785 nm diode laser was used for Raman excitation. Stokes Raman signals generated in the hollow core of the HC-PCF were guided to the collection optics and were analyzed by a Raman spectrometer for molecular identification.Results
Raman spectra have been obtained successfully from air, reference gases (hydrogen gas, oxygen gas, carbon dioxide gas), and human breath. The limit of detection of the system was found to be approximately 15 parts per million by CO~2~ concentration in the ambient air, characterized by the Raman peaks at 1286 cm[-1] and 1388 cm[-1]. This is a more than 100-fold improvement over the recently reported detection limit with a reflective capillary fibre-based Raman cell. The detection limit can be further improved by changes to the optical configurations, optimizing the interaction length of the HC-PCF and the use of sample pre-concentration method to enhance signal-to-noise ratio.Conclusion
This work demonstrated a working prototype of a simple, compact, and cost-effective breath analyzer based on hollow core photonic crystal fibre and Raman spectroscopy. With further improvement in the detection sensitivity, this method can potentially be used for lung cancer screening.
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P3.20 - Poster Session 3 - Early Detection and Screening (ID 174)
- Event: WCLC 2013
- Type: Poster Session
- Track: Imaging, Staging & Screening
- Presentations: 1
- Moderators:
- Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
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P3.20-011 - Lung density versus emphysema as predictor of malignancy risk of pulmonary nodules detected on first screening CT (ID 3353)
09:30 - 09:30 | Author(s): S. Lam
- Abstract
Background
The association between chronic obstructive pulmonary disease (COPD) and lung cancer has been previously reported. However, the mechanism whereby emphysema (a destructive process) promotes lung carcinogenesis (a proliferative process) has not been adequately explained. Emphysema is associated with lower lung density while lung inflammation is associated with increase in lung density. We hypothesized that lung density and emphysema are independent predictors of malignancy risk of lung nodules found on screening low dose spiral CT (LDCT).Methods
Image analysis was performed on a subset of LDCT scans (120 kVp, 40 mAs) from the Pan Canadian Early Detection of Lung Cancer Study and the BCCA Lung Health Study using the VIDA Diagnostics CT image analysis software Pulmonary Workstation 2. The lobe with the pulmonary nodule was first segmented. The average lung density surrounding the nodule was measured. Emphysema severity was defined as percentage of the lobe with -950 Hounsfield Units (HU). Multivariate logistic regression analysis was performed to determine if lung density and degree of emphysema were independently associated with malignant lung nodules.Results
A total of 161 subjects with lung nodules ≤20 mm were studied. The clinical and CT characteristics are shown in the Table 1. Table 1. Study variables by lung cancer status
While the presence of emphysema of any grade in both lungs by visual score was higher in the lung cancer group (78% versus 67%), the difference was not statistically significant in the univariate or multivariate analysis. Quantitative measurement of emphysema severity (area with -950 HU) in the same lobe where the lung nodule located showed that the degree of emphysema was less in patients with lung cancer (7.1% versus 9.3 %, P = 0.041 in the final multivariable logistic regression model consisting of family history, nodule size, type and spiculation). Lung density surrounding the lung nodule was significantly higher in the lung cancer group compared to the benign nodule group in univariate analysis (P = 0.024) but not in multivariable analysis.No Cancer Cancer P-value N= 95 66 Age 64±5 63±6 0.52 Gender : Men: Women 53% : 47% 38% : 62% 0.078 Current: Former smoker 61% : 39% 45% : 55% 0.051 Family history % 21% 38% 0.022 Nodule diameter 10.5 ± 3.0 12.9 ± 4.1 <0.001 Nodule Type – solid 53% 50% - part solid 11% 29% 0.003 - Non-solid 37% 20% Nodule location (upper versus middle or lower) 45% 65% 0.016 Spiculation (%) 18% 39% 0.017 Emphysema (visual score) % present 67% 78% 0.152 Density of lobe with nodule -848±32 -837±32 0.024 % emphysema in lobe with nodule 9.3%±9.7 7.1%±6.9 0.09 Conclusion
Our results suggest lung inflammation as reflected by increase in lung density may be a more important factor in lung carcinogenesis while emphysema may be more of a dosimeter for lung damage by tobacco smoke exposure. Further studies in a larger dataset are being performed to determine the incremental value of lung density in predicting the malignancy risk of lung nodules ≤ 2cm detected by screening LDCT.
