What is the recommended approach for monitoring and managing lung nodules?

Management of Lung Nodules: A Risk-Stratified Approach

The recommended approach for monitoring and managing lung nodules should follow a risk-stratified algorithm based on nodule size, characteristics, and patient risk factors, with nodules ≥8 mm or ≥300 mm³ requiring formal risk assessment using validated prediction models to guide further evaluation. 1, 2

Initial Assessment and Classification

• Do not offer follow-up or further investigation for nodules with benign characteristics including diffuse, central, laminated or popcorn pattern of calcification or macroscopic fat 1
• Do not offer follow-up for 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) 1, 2
• Do not offer nodule follow-up for people with nodules <5 mm in maximum diameter or <80 mm³ in volume 1
• Offer CT surveillance to people with nodules ≥5 mm to <8 mm or <300 mm³ 1, 2
• Use the same diagnostic approach for nodules detected incidentally as those detected through screening 1

Risk Assessment for Nodules ≥8 mm or ≥300 mm³

• Use the Brock model (full, with spiculation) for initial risk assessment of pulmonary nodules at presentation, especially in people aged ≥50 who are smokers or former smokers 1, 2
• Consider previous malignancy as a factor in risk assessment for further investigation 1
• Evaluate coexistent lung nodules detected in patients with known lung cancer in their own right; they should not be assumed to be malignant 1

Management Algorithm Based on Risk Assessment

Low Risk (<10% probability of malignancy)

• Offer CT surveillance according to a structured protocol 1, 2
• Assess growth for nodules ≥80 mm³ or ≥6 mm maximum diameter by calculating volume doubling time (VDT) on the basis of repeat CT at 3 months and 1 year 1
• Use a ≥25% volume change to define significant growth 1

Intermediate Risk (10-70% probability of malignancy)

• Perform PET-CT for risk assessment (provided size is greater than local PET-CT threshold) 1
• Consider image-guided biopsy, excision biopsy, or CT surveillance guided by individual risk and patient preference 1
• Offer percutaneous lung biopsy where the result will alter the management plan 1

High Risk (>70% probability of malignancy)

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

Special Considerations for Subsolid Nodules

• For part-solid nodules, management should be based on the size of the solid component, with larger solid components associated with higher risk of malignancy 2, 3
• Consider sublobar resection for pure ground-glass nodules (pGGNs) deemed to require surgical resection due to excellent long-term prognosis and low risk of local relapse 1

Follow-up Protocol

• For nodules requiring surveillance, follow a structured protocol with defined intervals 1, 2
• Base the risk assessment of people with multiple pulmonary nodules on that of the largest nodule 1
• For intermediate-risk nodules where PET-CT is performed, reassess risk using the Herder model 1

Diagnostic Procedures

• Offer bronchoscopy for the evaluation of pulmonary nodules with bronchus sign present on CT 1
• Consider augmenting yield from bronchoscopy using radial endobronchial ultrasound, fluoroscopy, or electromagnetic navigation 1
• Be aware of PET-CT limitations, including false-negatives (particularly in subsolid nodules) and false-positives (particularly in regions with endemic granulomatous disease) 2, 3

Patient Communication

• Offer accurate and understandable information to patients about the probability of malignancy of the pulmonary nodule 1
• Ensure patients have the opportunity to discuss concerns about lung cancer and surveillance regimens 1
• Offer patients with high probability of malignancy the choice of seeing a lung cancer nurse specialist 1

This structured approach to lung nodule management balances the need to identify malignant nodules early while avoiding unnecessary invasive procedures for benign nodules, ultimately optimizing patient outcomes in terms of morbidity, mortality, and quality of life.