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H. Ashraf
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P3.13 - Radiology/Staging/Screening (ID 729)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Radiology/Staging/Screening
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.13-011 - Use of Volume Growth and Fluor-Deoxy-Glucose Positron Emission Tomography in Evaluating Indeterminate Lung Nodules in Lung Cancer Screening (ID 8535)
09:30 - 09:30 | Author(s): H. Ashraf
- Abstract
Background:
Indeterminate lung nodules detected during lung cancer screening with low dose computed tomography (CT) present a challenge in distinguishing between malignant and benign disease. Our aim for this study is to compare the sensitivity and specificity of flour-deoxy-glucose positron emission tomography (FDG-PET), volume doubling time (VDT) and a combination of both in the diagnostic workup of indeterminate lung nodules in lung cancer screening.
Method:
The Danish Lung Cancer Screening Trial (DLCST) is a randomized controlled trial with heavy smokers between 50-70 years of age. The screening group underwent 5 annual rounds with low dose CT scan of the thorax. When a lung nodule was detected, participants could either be referred to diagnostic workup, 3-month follow-up or continue with the screening program. We included participants who had a 3-month follow-up scan. Before the follow-up scan was conducted, the participants received a FDG-PET scan. Nodules that were resected or stable for at least 2 years were included. FDG-uptake was categorized from most likely benign (uptake less than background uptake in the mediastinum) to most likely malignant (uptake as mediastinum or higher). VDT was calculated from nodule volume measurements from two time points closest to the FDG-PET scan date. We used a commercially available and validated semi-automated nodule evaluation software. Based on VDT the nodules were divided into three groups. Regressing nodules (VDT<0), slow growing nodules (VDT > 365 days - less likely malignant) and fast-growing nodules (VDT < 365 days – most likely malignant). Finally, we divided combined outcome into three groups: 1. Both tests suggest benignancy, 2. One of the tests suggest malignancy and 3. Both tests suggest malignancy. We used receiver operating characteristic (ROC) curves to compare sensitivity and specificity for the ability to predict a malignant or benign nodule.
Result:
A total of 87 lung nodules in 76 individuals were included. 68/87 (78%) were solid nodules. 41.5% were malignant. Nodule size ranged between 5 mm – 20 mm in largest diameter. The sensitivity and specificity of VDT alone were 61% and 90% respectively. For FDG-PET the sensitivity was 62% and specificity was 90%. Combined use of both tests showed an improvement in test sensitivity to 82% and a specificity of 79%.
Conclusion:
Combined use of FDG-PET and VDT is recommended in the diagnostic workup of indeterminate lung nodules in lung cancer screening.
