RESUMEN
BACKGROUND: A major prognostic indicator in patients with squamous cell carcinoma of the upper aerodigestive tract is the presence or absence of cervical metastasis. Nodal involvement at different levels affects treatment. Thus identification of the degree of nodal involvement is important. Evaluation of the neck by conventional imaging modalities (computed tomography or magnetic resonance imaging) is not completely accurate. Positron emission tomography (PET) scanning as a dynamic functional assessment may allow detection of multiple metastatic nodes at different levels. PURPOSE: We sought to compare the effectiveness of PET with pathologic examination for: presence, location, and number of cervical metastases in the clinically N-positive neck. SETTING: Tertiary care academic facility. Materials and methods From 1994 to 1997, 15 patients with clinically N-positive necks who had preoperative PET scans underwent 23 neck dissections. PET scans were correlated with the pathologic findings of the neck dissections in determining the ability to correctly identify the number and level(s) of nodal disease. RESULTS: When determining identification of the level of disease, PET demonstrated sensitivity of 81%; specificity, 99%; positive predictive value, 97%; negative predictive value, 90%; and accuracy, 92%. When evaluating the ability to correctly predict neck stage, PET demonstrated sensitivity of 86%, positive predictive value of 100%, and accuracy of 80% compared with clinical examination with sensitivity of 53% and accuracy of 53%. CONCLUSION: PET accurately identified disease in the N-positive neck. Its ability to identify multiple level disease may allow it to help predict the selectivity of neck dissection in the therapeutic protocol.
Asunto(s)
Carcinoma de Células Escamosas/diagnóstico por imagen , Neoplasias Laríngeas/diagnóstico por imagen , Neoplasias Orofaríngeas/diagnóstico por imagen , Tomografía Computarizada de Emisión/métodos , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/secundario , Femenino , Humanos , Neoplasias Laríngeas/patología , Metástasis Linfática/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cuello , Estadificación de Neoplasias , Neoplasias Primarias Secundarias/diagnóstico por imagen , Neoplasias Orofaríngeas/patología , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Positron emission tomography (PET) with the glucose analogue fludeoxyglucose F 18 uses the increased glucose uptake that is observed in neoplastic cells. It can differentiate between benign and malignant pulmonary lesions in patients with lung tumors. Applications of PET in extracranial head and neck neoplasms have included evaluating patients with unknown primary lesions, detecting primary and recurrent head and neck tumors, monitoring response to radiotherapy, and evaluating the N0 neck in oral cavity carcinomas. Its role in determining the presence of synchronous lung lesions has not been defined. PATIENTS AND METHODS: A retrospective review of 115 patients who underwent PET between October 1994 and October 1996 was performed to evaluate extracranial head and neck neoplasms. Fifty-nine (51%) previously untreated patients with squamous cell carcinoma of the upper aerodigestive tract were analyzed. RESULTS: Fifteen patients (25%) had PET scans that were positive for synchronous lung lesions. Five patients had a disease process that did not warrant further investigation; they did not have pathological confirmation of their lung lesions. Of these, 3 died of disease within 2 months of the diagnosis of primary head and neck squamous cell carcinoma, 1 was unavailable for follow-up, and 1 had lung lesions that were considered metastatic and no pathological confirmation of lung lesions was obtained. The remaining 10 patients with positive PET scan findings were investigated further: 8 patients had biopsy-confirmed lung lesions; 5 patients had positive findings on chest x-ray films; 8 had positive findings on computed tomographic scans; and 3 had positive findings on bronchoscopy. The results of 2 PET scans were false-positive. The PET scans were important in altering treatment in 3 patients; of these, 3 had negative findings on chest x-ray films, 2 had positive findings on computed tomographic scans, and 1 had positive findings on bronchoscopy. CONCLUSIONS: The overall sensitivity, positive predictive value, and accuracy of PET were 100%, 80%, and 80%, respectively. The overall accuracy of radiography of the chest, computed tomography of the chest, and bronchoscopy was 70%, 90%, and 50%, respectively. The accuracy of PET over bronchoscopy was statistically significant (P<.05). PET appears to be a promising imaging modality for the detection of synchronous lung lesions in patients with negative findings on chest x-ray films.