Lung and Colon Cancer

Figure 1

History: 75-year-old male with a history of head and neck cancer underwent a CT scan of the chest (Figure 2) which showed a solitary 2 cm left upper lobe nodule. The patient was referred to Main Street Radiology for a PET scan.

Findings: Whole body PET scan was performed demonstrating an intense hypermetabolic focus (Figure 1) corresponding to the pulmonary nodule seen on CT, indicative of carcinoma. A second abnormality was seen, within the right lower quadrant of the abdomen (Figure 1). In retrospect, a cecal mass is seen on the abdomen CT (figure 3) corresponding to the PET scan finding, compatible with carcinoma.

Figure 2

Discussion: PET scanning has been shown to be an excellent tool in imaging solitary pulmonary nodules, with sensitivity reported at approximately 95%. The success of PET scanning has significantly reduced the number of negative biopsies and thoracotomies at many institutions.

As the number of PET scans performed throughout the country increases, reports of incidental tumors are surfacing. At a conference sponsored by American College of Radiology, experts in the field of oncological PET scanning report that colorectal and thyroid carcinomas are the most commonly discovered incidental tumors.

Figure 3

Colorectal carcinoma is one of the most common indications for PET scanning. Sensitivity for metastatic disease has been reported to be greater than 90%, much higher that CT or MRI. Including PET in the work-up of colorectal carcinoma will help both the oncologist and surgeon to select the most appropriate treatment.