99mTc‐HMPAO‐leucocyte scintigraphy and [18F]FDG‐PET/CT for diagnosis and therapy monitoring in eleven patients with skull base osteomyelitis

Skull base osteomyelitis (SBO) is a severe condition that mostly occurs in diabetic patients. The duration of treatment is variable, and depends on the extent of the disease. There is currently no consensus on the best criteria for ending treatment. The objective of this study was to assess the value of 99m Tc-HMPAO-leukocyte scintigraphy (LS) and [18 F]-fluoro-desoxyglucose Positron Emission Tomography combined with CT ([18 F]FDG-PET/CT) for the diagnosis and the end-of-treatment assessment in SBO. Eleven patients with bacteriologically proven SBO were included in this study. Both LS and [18 F]FDG-PET/CT were positive in all patients at diagnosis. After 6 weeks of antibiotics, 7 patients were cured and 4 patients had ongoing disease. The sensitivity and specificity of nuclear imaging for healing assessment were 86% and 75% using LS, and 43% and 100% using [18 F]FDG-PET/CT, respectively. These results suggest that neither LS nor [18 F]FDG-PET/CT have adequate diagnostic value for healing assessment, and that the combined use of both techniques may be beneficial to the patients.