METHODS: Single photon emission computer tomography (SPECT) scintigraphy with 99mTc(V) -DMSA was performed on 32 patients with primary squamous cell carcinoma in oral cavity. The coronal aspect of SPECT image was chosen, the region of interest (ROI) of the affected neck was drawn, and the radioactivity uptake value of the ROI was given by the computer to compare with the contralateral neck. The results of 99mTc(V) -DMSA were compared with postoperative pathological studies. For false positive lymph nodes, semi-continuous slice was carried out for pathology examination.
RESULTS: The sensitivity, specificity and accuracy of 99mTc(V) -DMSA imaging for detecting metastatic lymph nodes were 75.0%, 90.0% and 84.4% respectively. The ROI values of the affected neck are higher than that of the contralateral part in the 9 positive patients (t = 8.128, P = 0.000 04). Metastasis was not found in the enlarged lymph nodes of the false positive patients.
CONCLUSIONS: 99mTc(V) -DMSA SPECT imaging has fairly high affinity with metastatic lymph nodes in the neck especially in the cN0 patients and is helpful for designing proper neck dissection.