Pulmonary nodules: volume repeatability at multidetector CT lung cancer screening

Area of Science:

• Radiology
• Pulmonary Medicine
• Medical Imaging Analysis

Background:

• Lung cancer screening trials utilize computed tomography (CT) to detect pulmonary nodules.
• Accurate volumetric assessment of nodules is crucial for determining malignancy risk and guiding patient management.
• Repeatability of volumetric measurements is essential for tracking nodule changes over time.

Purpose of the Study:

• To evaluate the in vivo volumetric repeatability of an automated software algorithm for pulmonary nodules detected during lung cancer screening.
• To determine the accuracy and reliability of semi-automatic volumetry in a clinical screening setting.

Main Methods:

• Data from 1236 baseline low-dose CT scans from the Multicentric Italian Lung Detection project were analyzed.
• Participants with indeterminate nodules (>60 mm³) undergoing repeat CT at 3 months were included; nonsolid, part-solid, and pleural-based nodules were excluded.
• Volumetric measurements were taken at baseline, 3 months, and 12 months, with repeatability assessed using Bland-Altman analysis.

Main Results:

• 233 eligible nodules in 101 subjects were analyzed (mean volume 98.3 mm³).
• The 95% confidence interval for volume difference was ±27%, with ~70% of measurements showing <10% relative difference.
• No malignant lesions were identified during the follow-up period.

Conclusions:

• Semi-automatic volumetry demonstrates sufficient accuracy and repeatability for pulmonary nodule assessment.
• This automated approach can assist in the effective management of lung nodules within lung cancer screening programs.