Table 3.

Challenges of different modalities for the diagnosis of lung cancer in patients with ILDs based on refs. [14,52,70,82,84,85,86,87,88,89].

Modality	Diagnostic Challenges
Pulmonary function tests (PFTs)	In CPFE, preserved lung volumes in patients may overestimate patients’ functional operability. DLCO is the most sensitive parameter
HRCT	Tumors may be directly adjacent to fibrotic lesions, with an underestimation of tumor size. Reduced sensitivity and specificity in evaluating mediastinal lymph nodes (reactive mediastinal lymph node enlargement may be seen in ILDs without lung cancer)
PET-scan	FDG-positive mediastinal lymph nodes may be reactive and not due to lung cancer infiltration
CT-guided biopsy	Motion artifacts and biopsy of fibrotic lesions adjacent to the tumor may give inconclusive results. Pneumothorax may be more difficult to treat.
Bronchoscopy with biopsy	Risk of acute exacerbation of ILD (AE-ILD). Tumor identification with radial EBUS or navigational bronchoscopy in fibrotic milieu may be more challenging, compared to patients without ILDs
Surgical biopsy	Increased risk of AE-ILD

CPFE: combined pulmonary fibrosis and emphysema; DLCO: diffusing capacity for carbon monoxide; HRCT: high-resolution computed tomography; PET: positron-emission tomography; ILD: interstitial lung disease.