Single photon emission tomography: Scintigraphy in the assessment of mandibular invasion by head and neck cancer

Background. This study was performed to determine the effectiveness of single photon emission tomography (SPET) in contributing to the initial staging of patients with cancers of the head and neck because information about osseous infiltration of head and neck cancer is of major importance for staging and planning of treatment. Methods. A retrospective analysis of 89 cases with probable tumor infiltration of the mandible by oral/pharyngeal cancer was undertaken by comparing the preoperative SPET as well as CT-scans, if available, with clinical and postoperative histological examinations. Results. For SPET examinations, a sensitivity of 95% and a specificity of 48% were calculated. The positive predictive value was 65%, and the negative predictive value was 93%. CT scans showed a sensitivity of 75% and a specificity of 78%. The positive predictive value was 65%, and the negative predictive value was 93%. Conclusions. SPET is a powerful method to detect infiltration of carcinomas into the head and neck skeleton. Its sensitivity is high and superior to CT scans, although the specificity is small due to a high number of false positive results.