Usefulness of FDG-PET in diagnosis and management for refractory osteonecrosis of jaws

Objectives Bisphosphonate-related osteonecrosis of jaws (BRONJ) and osteoradionecrosis (ORN) still represent the most complicated inflammatory condition in oral and maxillofacial region. It is very difficult to correctly evaluate the degree and extent of necrosis and infection. We have performed Hyperbaric oxygen (HBO) combined with conservative surgery for advanced cases. FDG-PET has been found to accumulate non-specifically at sites of infection. The aim of this prospective study was to appraise the value of FDG-PET in the diagnosis and management of refractory osteonecrosis of jaws.

Methods Six patients(Age: 57-80; M/F: 3/3)with BRONJ (n=3) and ORN (n=3) were enrolled in this study. The treatment protocol includes 20 times of pre-operative HBO, conservative surgery, and then 10 times of post-operative HBO. Each patient underwent FDG-PET studies prior to and after the pre-operative HBO. SUVmax was calculated for quantitative analysis of FDG uptake in the lesions.

Results FDG-PET detected the focal area of inflammation in all osteonecrosis cases. In the study of BRONJ, two cases showed remarkably decreased SUVmax, but one case increased SUVmax after HBO. In the study of ORN, SUVmax did not change in two cases, increased SUVmax was noted after HBO in one case which showed poor clinical course, resulting in radical resection with reconstruction after 10 weeks.

Conclusions These preliminary results indicate that FDG-PET is useful for diagnosing osteonecrosis and monitoring the effect of HBO. Of particular, monitoring HBO therapy with FDG-PET may hold a promise for prognostic assessment in patients with osteonecrosis.