Laryngoscope 1998 Feb;108(2):232-6
Positron emission tomography in the evaluation of the N0 neck.
Myers LL, Wax MK, Nabi H, Simpson GT, Lamonica D.
The presence of cervical lymph node metastasis in patients with head and neck
cancer is associated with an unfavorable prognosis. Reports vary as to whether
various conventional radiographic studies, such as computed tomography (CT) and
magnetic resonance imaging, confer an advantage over physical examination in the
patient without clinical findings of cervical metastasis (N0). Positron emission
tomography (PET) is a functional imaging modality that has recently been used
for head and neck neoplasms. The use of PET in the evaluation of the N0-staged
neck in 14 consecutive patients with squamous cell carcinoma (SCC) of the upper
aerodigestive tract is reported. Seven patients (50%) undergoing 13 neck
dissections had pathologic evidence of disease. PET scans were positive in five
patients with pathologically confirmed cervical metastasis. PET scans were
negative in seven patients (11 neck dissections) with no pathologic evidence of
disease. PET scans were positive for unilateral cervical metastasis in two of
three patients with involvement of a single lymph node. PET scans were positive
in two of three patients with more than two lymph nodes involved. PET had an
accuracy of 100% in the eight patients with SCC of the oral cavity. In patients
with oropharyngeal or hypopharyngeal carcinoma PET localized cervical metastasis
in two of four patients with neck metastasis. In the patient with an N0-staged
neck on clinical examination, PET was found to have an overall sensitivity of
78%, specificity of 100%, positive predictive value of 100%, negative predictive
value of 88%, and accuracy of 92%. CT demonstrated sensitivity of 57%,
specificity of 90%, positive predictive value of 80%, negative predictive value
of 75%, and accuracy of 76%. PET showed a trend in increased accuracy (P = 0.11)
over CT. PET appears to be a promising diagnostic aid that may be applied when
evaluating the N0-staged neck, especially for SCC of the oral cavity.
