What is the appropriate management for patients presenting with pulmonary nodules?

Management of Pulmonary Nodules

The management of pulmonary nodules should follow a risk-stratified approach based on nodule size, characteristics, and patient risk factors, with nodules ≥8 mm or ≥300 mm³ requiring risk assessment using validated prediction models to guide further evaluation. 1

Initial Assessment

Nodule Characteristics That Do Not Require Follow-up

• Nodules with diffuse, central, laminated or popcorn pattern of calcification or macroscopic fat should not be offered follow-up or further investigation 1
• Typical perifissural or subpleural nodules (homogeneous, smooth, solid nodules with lentiform or triangular shape within 1 cm of a fissure or pleural surface and <10 mm) do not require follow-up 1
• Nodules <5 mm in maximum diameter or <80 mm³ in volume do not require follow-up 1

Risk Assessment for Nodules ≥8 mm or ≥300 mm³

• Use the Brock model (full, with spiculation) for initial risk assessment, especially in smokers or former smokers aged ≥50 1

• Clinical risk factors to consider include:

  • Increasing age 1
  • History of smoking and pack-years smoked 1
  • Previous malignancy 1

• Radiological risk factors include:

  • Increasing nodule diameter 1
  • Spiculation 1
  • Pleural indentation 1
  • Upper lobe location 1

Management Algorithm Based on Risk Assessment

Low Risk of Malignancy (<10%)

• CT surveillance is recommended 1
• For solid nodules 5-8 mm, follow-up CT at 3-12 months is appropriate 1, 2
• For nodules that remain stable, consider additional follow-up at 18-24 months 1

Intermediate Risk of Malignancy (10-70%)

• PET-CT is recommended for further risk assessment (provided nodule size is above local PET-CT threshold) 1
• After PET-CT, use Herder model to reassess probability of malignancy 1
• Consider image-guided biopsy; other options include excision biopsy or CT surveillance based on individual risk and patient preference 1

High Risk of Malignancy (>70%)

• Consider excision or non-surgical treatment (with or without image-guided biopsy) 1
• Surgical resection should preferentially be by video-assisted thoracoscopic surgery (VATS) rather than open approach 1

Special Considerations for Subsolid Nodules

Part-Solid Nodules

• For part-solid nodules ≤8 mm, suggest CT surveillance at approximately 3,12, and 24 months, followed by annual CT for 1-3 additional years 1
• For part-solid nodules >8 mm, suggest repeat CT at 3 months followed by further evaluation with PET, nonsurgical biopsy, and/or surgical resection for persistent nodules 1
• Part-solid nodules >15 mm should proceed directly to further evaluation with PET, nonsurgical biopsy, and/or surgical resection 1

Pure Ground-Glass Nodules

• For persistent ground-glass nodules >10 mm, the probability of malignancy is 10-50% 2
• These typically represent slow-growing malignancies 2
• Consider CT surveillance at 3,12, and 24 months, with additional follow-up based on stability 1

Multiple Nodules

• In patients with a dominant nodule and additional small nodules, each nodule should be evaluated individually 1
• Curative treatment should not be denied unless there is histopathological confirmation of metastasis 1
• Multiple nodules may represent metastatic disease, especially in patients with known extrapulmonary malignancy 1

Diagnostic Procedures

• Percutaneous lung biopsy is usually appropriate for nodules ≥8 mm when the result will alter management 1
• Consider bronchoscopy for nodules with a bronchus sign present on CT 1
• PET-CT has approximately 97% sensitivity and 78% specificity for nodules ≥1 cm 1
• Be aware of PET-CT limitations: false-negatives may occur with well-differentiated adenocarcinomas, bronchioloalveolar carcinomas, and carcinoid tumors; false-positives may occur with tuberculosis, fungal infections, or sarcoidosis 1

Common Pitfalls to Avoid

• Do not assume all nodules in patients with known lung cancer are malignant; evaluate coexistent lung nodules on their own merit 1
• Do not use biomarkers in the assessment of pulmonary nodules 1
• Do not use PET to characterize part-solid lesions in which the solid component measures ≤8 mm 1
• Remember that a non-diagnostic biopsy result does not exclude malignancy 1
• Consider the risk of pneumothorax when deciding on transthoracic needle biopsy, especially in patients with poor pulmonary reserve 1