This 62-year old woman presented with a CT showing a right basal lung mass with associated right hilar and mediastinal adenopathy. A needle biopsy confirmed bronchoalveolar cell carcinoma involving the right lower lobe. The patient was referred by a thoracic surgeon for a whole body PET evaluation prior to surgery.

Criteria for PET Referral:
1. To more accurately stage the patient.
2. To determine if surgical intervention would be the most appropriate treatment.

The PET scan confirmed the focal abnormality in the right lower lobe, consistent with the known bronco-alveolar cell carcinoma, and the right hilar and mediastinal adenopathy. In addition, PET revealed metabolic activity in the posterior subcarinal region and mild focal abnormality in the region of the aorto-pulmonary window, highly suspicious for metastatic disease.

Since the PET scan (left) detected more extensive lymph node involvement that was seen on CT, her treatment plan was changed to pre-surgical chemotherapy and radiation therapy.

A PET scan taken 10-weeks later following chemotherapy confirmed a dramatic response with only a small area of mild metabolic activity remaining. Following radiation therapy six weeks afterwards, the PET scan (right) showed no viable tumor.

Following systemic treatment, surgery was then scheduled to explore the region for any microscopic lesions that might remain.

Metabolic response measured by PET is an earlier indicator of treatment efficacy than either CT or MR since such responses frequently precede any anatomic changes. Efficacy of treatment can be more accurately measured, especially when the level of tumor metabolism is compared on PET scans taken before and after therapy.