Mediastinal Staging of Non-Small Cell Lung Carcinoma
Mediastinal Staging of Non-Small Cell Lung Carcinoma
Background: We evaluated the accuracy of computed tomography (CT) and positron-emission tomography (PET) in the mediastinal staging of non-small cell lung cancer.
Methods: Between May 14, 1999, and November 28, 2000, computerized tomography (CT) and positron-emission tomography (PET) were used to clinically stage 94 consecutive patients with non-small cell carcinoma of the lung (NSCCL). All patients underwent subsequent surgical staging with mediastinoscopy, anterior mediastinotomy, and/or thoracotomy with mediastinal lymphadenectomy.
Results: Overall accuracy was the same for both procedures. False-negative results occurred 3 times more often with CT; false-positive results occurred twice as often with PET. Sensitivity and specificity were 64% and 94%, respectively, for CT, versus 88% and 86%, respectively, for PET. Positive and negative predictive values were 80% and 88%, respectively, for CT, versus 71% and 95%, respectively, for PET.
Conclusion: In addition to routine use of CT, PET seems to achieve high negative predictive value in the evaluation of mediastinal disease; PET seems particularly helpful in assessing absence of tumor in bulky nodes after neoadjuvant chemotherapy and/or radiotherapy.
It has been stated, "The tumor-node-metastasis system (of staging) has proved to be the best method . . . to determine treatment strategies and ultimate prognosis . . . (and) the involvement of local (intrapulmonary) or regional (extrapulmonary) lymph nodes remains the most important predictor of outcome after resection of lung cancer."
Regional, extrapleural, and distant metastatic disease so adversely affect the prognosis of patients with non-small cell carcinoma of the lung (NSCCL) that surgical resection is not an appropriate option for treatment in most patients with stage III and IV disease (ie, patients with regional mediastinal or distant spread of disease, respectively), at least not until they have received preoperative therapy.
Computed tomography (CT) has supplanted simple chest roentgenograms, planigrams, fluoroscopy, and radionuclide bone scanning for routine clinical staging purposes. Now the emergence of positron-emission tomography (PET) allows a marriage of metabolic imaging (PET) to complement the anatomic imaging of CT, hopefully to more appropriately guide therapy.
Positron-emission tomography is a relatively noninvasive nuclear technique that delivers high resolution images using positron-emitting radiotracers, most commonly 2-(F-18)-fluoro-2-dioxy-D-glucose (FDG). Because malignant cells typically exhibit accelerated glycolysis, FDG is rapidly concentrated and well imaged, with a high tumor-to-background ratio. There is also concentration in the brain, urinary tract, and areas of inflammation. Positron-emission tomography may be used as a diagnostic aid in evaluating pulmonary nodules/masses, extrathoracic staging, and monitoring therapy, as well as for mediastinal staging, which is the subject of this study.
Background: We evaluated the accuracy of computed tomography (CT) and positron-emission tomography (PET) in the mediastinal staging of non-small cell lung cancer.
Methods: Between May 14, 1999, and November 28, 2000, computerized tomography (CT) and positron-emission tomography (PET) were used to clinically stage 94 consecutive patients with non-small cell carcinoma of the lung (NSCCL). All patients underwent subsequent surgical staging with mediastinoscopy, anterior mediastinotomy, and/or thoracotomy with mediastinal lymphadenectomy.
Results: Overall accuracy was the same for both procedures. False-negative results occurred 3 times more often with CT; false-positive results occurred twice as often with PET. Sensitivity and specificity were 64% and 94%, respectively, for CT, versus 88% and 86%, respectively, for PET. Positive and negative predictive values were 80% and 88%, respectively, for CT, versus 71% and 95%, respectively, for PET.
Conclusion: In addition to routine use of CT, PET seems to achieve high negative predictive value in the evaluation of mediastinal disease; PET seems particularly helpful in assessing absence of tumor in bulky nodes after neoadjuvant chemotherapy and/or radiotherapy.
It has been stated, "The tumor-node-metastasis system (of staging) has proved to be the best method . . . to determine treatment strategies and ultimate prognosis . . . (and) the involvement of local (intrapulmonary) or regional (extrapulmonary) lymph nodes remains the most important predictor of outcome after resection of lung cancer."
Regional, extrapleural, and distant metastatic disease so adversely affect the prognosis of patients with non-small cell carcinoma of the lung (NSCCL) that surgical resection is not an appropriate option for treatment in most patients with stage III and IV disease (ie, patients with regional mediastinal or distant spread of disease, respectively), at least not until they have received preoperative therapy.
Computed tomography (CT) has supplanted simple chest roentgenograms, planigrams, fluoroscopy, and radionuclide bone scanning for routine clinical staging purposes. Now the emergence of positron-emission tomography (PET) allows a marriage of metabolic imaging (PET) to complement the anatomic imaging of CT, hopefully to more appropriately guide therapy.
Positron-emission tomography is a relatively noninvasive nuclear technique that delivers high resolution images using positron-emitting radiotracers, most commonly 2-(F-18)-fluoro-2-dioxy-D-glucose (FDG). Because malignant cells typically exhibit accelerated glycolysis, FDG is rapidly concentrated and well imaged, with a high tumor-to-background ratio. There is also concentration in the brain, urinary tract, and areas of inflammation. Positron-emission tomography may be used as a diagnostic aid in evaluating pulmonary nodules/masses, extrathoracic staging, and monitoring therapy, as well as for mediastinal staging, which is the subject of this study.
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