Morphological Predictors of Primary Lung Cancer among Part-Solid Ground-Grass Nodules on High-Resolution CT

Area of Science:

• Pulmonology
• Radiology
• Oncology

Background:

• Computed tomography (CT) advancements enhance peripheral pulmonary nodule detection, including ground-glass opacities (GGOs).
• Part-solid ground-glass nodules (GGNs) require accurate differentiation between primary lung cancer and other diagnoses.

Purpose of the Study:

• To identify high-resolution CT (HRCT) imaging predictors for distinguishing primary lung cancer in part-solid GGNs.
• To evaluate the positive predictive value of specific CT features for diagnosing primary lung cancer in part-solid GGNs.

Main Methods:

• Retrospective analysis of 609 patients with lung nodules undergoing surgery or observation.
• Review of pre-operative HRCT scans to examine CT imaging features of part-solid GGNs.
• Assessment of consolidation-to-tumor ratio (CTR), pleural indentation, and tumor border clarity for diagnostic accuracy.

Main Results:

• Part-solid GGNs showed a higher proportion of primary lung cancer (91.9%) compared to solid (70.3%) or pure GGNs (66.7%).
• High positive predictive values for primary lung cancer were observed for CTR < 0.5 (98.1%), pleural indentation (96.4%), and clear tumor border (96.7%).
• Combining CTR < 0.5 and a clear tumor border yielded 100% positive predictive value for primary lung cancer, with 40.8% sensitivity.

Conclusions:

• Part-solid GGNs with CTR < 0.5 and a clear tumor border on HRCT are highly indicative of primary lung cancer.
• These imaging features may allow omission of preoperative pathological diagnosis in select patients.
• HRCT imaging plays a crucial role in the non-invasive diagnosis of lung nodules.