MANDIBULAR INVASION DIAGNOSED BY SPECT

To date no investigation has proven accurate and reliable for assessin g mandibular invasion by carcinoma prior to surgery. This prospective study compared a new imaging modality, single photon emission computed tomography (SPECT), with clinical examination and high resolution CT scanning to evaluate the sensitivity and specificity of each method in detecting mandibular invasion by squamous cell carcinoma. Twenty-nine patients (21 men, 8 women) with an oral cavity/oropharyngeal carcinom a were studied. All underwent primary surgery and/or radiotherapy wher e indicated. Resected mandibles were decalcified and examined for tumo ur infiltration. Imaging studies were read independently by two experi enced observers. Clinical examination predicted bone invasion with a s ensitivity of 90% and a specificity of only 25%. CT had a sensitivity of 89% and a specificity of 57% while SPECT imaging had a sensitivity of 100% and a specificity of 29%. Using Fisher's exact test and the Ka ppa statistic for pairwise comparisons between each method, SPECT imag ing was complementary to CT in the pre-operative assessment of mandibu lar invasion.