Introduction
Bronchogenic carcinoma is the most common
cause of cancer death in men and women both in the United States and worldwide
[1,121]. In the US, lung cancer accounts for 32% of cancer deaths in men and 25% of cancer
deaths in women [2]. Approximately 160,400 patients will die as a result of the disease
over the course of the next year [2]. Among patients who survive one lung
cancer, there is a 2.5% annual risk of developing a second primary lung
cancer [157]. Imaging studies play a key role in the detection,
staging, and post-treatment follow-up of patients with bronchogenic carcinoma. For
lung cancer, the strongest prognostic factor for survival is whether the tumor can be
completely resected. Because there is significant morbidity, mortality, and cost
associated with surgery, it is important to identify and to exclude from primary surgical
therapy those patients who will not benefit from resection [4]. Proper staging for
bronchogenic carcinoma is essential as treatment options and patient prognosis are
directly related to the patient's stage at presentation.
Lung cancer is staged according to a TNM (T= primary
tumor, N= regional lymph nodes, M= distant metastasis) classification system. In June of
1997, the American Joint Committee on Cancer and the Union Internationale Contre le Cancer
revised the stage groupings of the TNM subsets in the International System for Staging
Lung Cancer. The revisions were made to provide greater specificity for identifying
patient groups with similar prognoses and treatment options based upon clinical,
surgical-pathologic, and follow-up information for 5,319 patients treated for primary lung
cancer [3]. A basic understanding of this new classification scheme is essential for any
physician involved with the diagnosis or treatment of lung cancer.
This course emphasizes the radiologic findings for proper
staging of bronchogenic carcinoma based upon the revised International System
classification scheme: primary tumor, nodal status, and metastases, -- TNM. An emphasis
will be placed on computed tomography which is presently the standard imaging modality
used for the evaluation of bronchogenic carcinoma. The usefulness and limitations of
computed tomography will be discussed. Additional information regarding the use of other
imaging modalities in the staging of bronchogenic carcinoma is provided for purposes of
completeness. Because radiology and computed tomography also play a role in the diagnosis
of lung cancer, the transthoracic percutaneous biopsy is also discussed.
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