Role of FDG-PET in evaluating different 4 types of chronic osteomyelitis of jaws in combination with 3-phase bone scintigraphy

Objectives Chronic osteomyelitis of Jaws still represents the most complicated inflammatory condition in oral and maxillofacial region, including bisphosphonate-related osteonecrosis of jaws (BRONJ), osteoradionecrosis (ORN), and diffuse sclerosing osteomyelitis (DSO) as well as odontogenic osteomyelitis. It is very difficult to correctly diagnose these refractory diseases. Inadequate diagnosis may often lead to intractable conditions. The aim of this prospective study was to appraise the value of FDG-PET in the diagnosis of 4 types of osteomyelitis of jaws, combined with 3-phase bone scintigraphy.

Methods Forty two patients (Age: 35-81; M/F: 21/21) with osteomyelitis of Jaws (6 BRONJ, 12 ORN, 14 odontogenic infection, and 10 DSO) were enrolled in this study. Each patient underwent FDG-PET and 3-phase bone scintigraphy , before surgical intervention during the same period. Each image of 3-phase bone scintigraphy was analyzed using Grading system (G0-G3). Radiographic characteristics were compared with histology.

Results FDG-PET detected the focal area of inflammation in 35/42 cases. The mean SUVmax of BRONJ, ORN, odontogenic, and DSO was 4.45, 3.47, 2.24, and 1.99, respectively. The mean grade of perfusion image was 1.7, 0.4, 0.2, and 0.2; pool image was 2.2, 1.4, 1.1, and 2.1; and static image was 2.5, 1.9, 1.5, and 2.8, respectively. BRONJ showed significantly higher accumulation in PET and perfusion images than odontogenic and DSO. Static images in BRONJ and DSO showed significantly higher uptake than odontogenic, reflecting higher remodeling activities. DSO showed low SUV corresponding to osteolytic areas, in striking contrast with increased uptake in pool images.

Conclusions FDG-PET combined with 3-phase bone scintigraphy is useful for the evaluation of osteomyelitis of Jaws, because FDG-PET facilitates differentiation of inflammation and infection from bone remodeling, which is sometimes difficult to be characterized by other images