State of the Art: Lung Cancer Staging Using Updated Imaging Modalities

Abstract

Lung cancer is among the most common mortality causes worldwide. This scientific article is a comprehensive review of current knowledge regarding screening, subtyping, imaging, staging, and management of treatment response for lung cancer. The traditional imaging modality for screening and initial lung cancer diagnosis is computed tomography (CT). Recently, a dual-energy CT was proven to enhance the categorization of variable pulmonary lesions. The National Comprehensive Cancer Network (NCCN) recommends usage of fluorodeoxyglucose positron emission tomography (FDG PET) in concert with CT to properly stage lung cancer and to prevent fruitless thoracotomies. Diffusion MR is an alternative to FDG PET/CT that is radiation-free and has a comparable diagnostic performance. For response evaluation after treatment, FDG PET/CT is a potent modality which predicts survival better than CT. Updated knowledge of lung cancer genomic abnormalities and treatment regimens helps to improve the radiologists' skills. Incorporating the radiologic experience is crucial for precise diagnosis, therapy planning, and surveillance of lung cancer.

Keywords: FDG PET/CT; chest; computed tomography (CT); diffusion-weighted MRI; lung cancer.

Figure 1

A 64-year-old male cigarette smoker with bronchogenic adenocarcinoma. Axial CT image (A) reveals spiculated right upper lung lobe mass ($4.5\times 2.5$ cm). Axial CT image at distal level (B) reveals ipsilateral hilar, mediastinal LN with central necrosis, and pericardial effusion. Axial CT image of upper abdomen (C) reveals bilateral metastatic suprarenal masses.

Figure 2

A 65-year-old male cigarette smoker with bronchogenic large-cell carcinoma. Axial-fused FDG PET/CT image (A) reveals FDG-avid large left upper lung lobe mass ($5.5\times 6$ cm) with maximum standardized uptake value (SUVmax) of $11.8$. Axial-fused FDG PET/CT image at distal level (B) reveals FDG-avid ipsilateral hilar LN with SUVmax 7. No FDG-avid distant metastatic deposits, imaging-based staging IIIA (T3 N1 M0).

Figure 3

A 38-year-old male with bronchogenic adenocarcinoma. Axial T2 fast spin echo (FSE) with fat suppression (A) reveals spiculated left upper lung lobe mass of intermediate to high signal intensity. Diffusion-weighted image, high b-value $=800$ mm²/s (B) and corresponding ADC image (C) reveal a mass-constrained diffusion pattern with low ADC value of $1.12\times {10}^{-3}$ mm²/s.