Radiological Signs of Tumor Dissemination

Radiology plays a central role in the assessment of tumor dissemination in a process called “staging.” Precise radiological tumor staging is fundamental for treatment decisions in patients with lung cancer. Tumor assessment includes both the local staging, which focuses mainly on regional tumor extension and potential technical resectability, and the distant staging to rule out or confirm the presence of disease dissemination. Computed tomography (CT), positron-emission tomography (PET)/CT, magnetic resonance imaging (MRI), and ultrasound are the main imaging modalities used for staging in patients with lung cancer. Each type of examination has its strengths and weakness. While MRI is preferred to assess mediastinal or chest wall infiltration, PET/CT is excellent to detect distant metastasis. In this article, we will summarize radiological signs of tumor spread and illustrate this with representative image examples.