Knowledge of the presence and degree of extend of bone infiltration is crucial for planning resection of potential bone infiltrating squamous cell carcinomas of the head and neck region. Routinely, plain film radiography, CT and MRI are used for preoperative staging, but go along with a relatively high rate of false information. Scintigraphy with 99m-Tc-bisphosphonate has the ability to display increased metabolic bony activity. If combined with anatomical imaging, as in SPECT/CT, it facilitates a precise localization of the malignant bone lesions. The aim of this study was to analyse advantages of SPECT/CT compared to standard imaging modalities and histology. 25 patients with biopsy proven oromaxillofacial malignancies adjacent to the mandible underwent 99m-Tc-bisphosphonate SPECT/CT, MRI, CT and conventional radiography prior to partial surgical resection of the mandible. Bone infiltration was first evaluated with plain radiographs, CT and MRI. In a second reading SPECT/CT data were also included. Results were compared between the different imaging modalities and the final histological specimens concerning extend of bone invasion.

Osseous infiltration was found in 16 patients (64%) when analysing the conventionally employed imaging modalities. Using SPECT/CT data, 3 additional up till then unidentified cases (12%) of initial discrete bone infiltration were obtained, which were not visible in CT or MRI. Preliminary data showed that hybrid SPECT/CT can provide important additional information about malignant mandibular bone infiltration. Due to this information, surgical intervention can be planned and performed more precisely. Patient outcome can be improved by prevention of unnecessary or overextended bone resections.

Conflict of interest: None declared.