Fiducial marker used to guide radiation therapy in lung cancer

A CT scan of the chest shows a 3 mm nodule in the right upper lobe bronchus. Image B is a magnified view of the lesion (arrowhead). Endoscopic biopsy confirmed a diagnosis of squamous cell carcinoma. Fiducial marker to guide radiation therapy was placed endoscopically. A CT scan (C), and a chest x-ray magnified in D and E show the high density fiducial marker (arrows).