Assessment of cervical lymph node status in head and neck cancer patients: palpation, computed tomography and low field magnetic resonance imaging compared with ultrasound-guided fine-needle aspiration cytology.

OBJECTIVE: Since the assessment of lymph node metastases in head and neck cancer patients remains a major problem, the findings of different imaging methods and the role of these methods in the clinical management are compared.
MATERIAL AND METHODS: Palpation, computed tomography (CT) and low field magnetic resonance imaging (MRI; 0.1 T) are evaluated and compared with ultrasound-guided fine-needle aspiration cytology (US-guided FNAC) prospectively in 105 consecutive patients with a primary cancer in the head and neck region.
RESULTS: In the subgroup of 86 patients with palpable normal necks, CT showed lymph nodes fulfilling the radiologic criteria for malignancy in 27% (23/86), MRI in 17% (10/60) and US in 14% (12/86) of the patients US guided FNAC usually showed malignancy in necks containing lymph nodes with central necrosis on CT, but the enlarged lymph nodes that were also common on the contralateral side were often benign on cytology. In 5 patients, FNAC under US-guidance showed malignancy although none of them had lymph nodes fulfilling the radiologic criteria for malignancy. In the other subgroup of 19 patients with palpable metastatic necks, 2 patients had bilateral metastases detected by all imaging methods but not by palpation.
CONCLUSION: CT is superior to low field MRI in depicting small pathologic lymph nodes. Unlike lymph node structure, lymph node size is not a highly reliable criterion for malignancy. The findings must be correlated in relation to the primary disease. Since FNAC under US-guidance offers additional information about enlarged lymph nodes and since it can show malignancy in small lymph nodes not found by other methods, it can be recommended for most head and neck cancer patients irrespective of the use of CT or MRI.