Barry Howard Gross MD, Presenter: Nothing to Disclose

Richard Kevin Brown MD, Abstract Co-Author: Investor, Image Exchange Partners, LLC

Gregory Kalemkerian MD, Abstract Co-Author: Consultant, ImClone Systems Incorporated Consultant, Merck & Co, Inc Speaker, Genentech, Inc Speaker, Eli Lilly and Company Research grant, Millennium Pharmaceuticals, Inc Research grant, Abbott Laboratories

Chest CT scanning is typically performed for lung cancer staging, but inclusion of structures in the neck, abdomen, and pelvis varies from institution to institution; even within a given institution, there are differences from patient to patient.  We reviewed 144 consecutive patients who had concurrent CT and PET-CT for lung cancer staging to determine the optimal anatomic coverage at CT for best patient staging.

We reviewed all lung cancer staging PET-CT scans performed and interpreted at the University of Michigan between July 15, 2003 and August 3, 2005, and correlated them with staging chest CT scans performed within 50 days of the PET-CT study.  There were 144 patients who had both studies within that time frame.  We reviewed the results of subsequent imaging studies, and also the records of surgical and biopsy procedures to determine the final stage of each cancer.

Of our 144 patients, 42 had useful findings at PET that were not visualized at chest CT.  Of these, 15 were not issues of anatomic coverage; they were within the area that we traditionally scan (lung apices through caudal adrenal glands), but were not seen or invisible at standard CT.  Of 27 patients whose disease was missed by standard CT, 12 had enlarged supraclavicular lymph nodes, some of which were visible or partly visible in retrospect, and 9 had skeletal metastases.  Overall, of the 27 patients with disease missed by CT because of anatomic coverage issues, 13 resulted in a change of staging, 9 did not influence staging, 3 were second primary neoplasms (cecal carcinoma, hepatoma, and renal cell carcinoma), and 2 had unknown influence (1 cecal lesion that was not further evaluated, 1 patient whose final stage was not conclusively established).

CT scanning for lung cancer staging from the lung apices through the caudal aspects of the adrenal glands was most likely to miss supraclavicular lymph nodes and skeletal metastates in our 144 patients.  Where PET-CT is unavailable or not routinely utilized in all patients with lung cancer, starting chest CT slightly more cephalad (in the lower neck) and supplementing liberally with bone scan correlation will eliminate most CT staging errors.

PET-CT for lung cancer staging reveals that chest CT from the lung apices through the caudal aspects of the adrenals is most likely to miss supraclavicular lymph nodes and skeletal lesions.

Gross, B, Brown, R, Kalemkerian, G, Anatomic Extent of CT Scanning Required for Complete Lung Cancer Staging: Lessons from PET-CT Correlation.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010828.html