Use of FDG-PET to detect a chronic odontogenic infection as a possible source of the brain abscess.

This study describes the use of (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) to detect a chronic odontogenic infection as the possible origin of a brain abscess (BA). A 74-year-old man with esophageal carcinoma was referred to our department to determine the origin of a BA in his oral cavity. He had no acute odontogenic infections. The BA was drained, and bacteria of the Staphylococcus milleri group were detected. Whole body FDG-PET revealed that the only sites of definite uptake of FDG were the esophageal carcinoma and the left upper maxillary region (SUVmax: 4.5). These findings suggested that the BA may have originated from a chronic periodontal infection. Six teeth with progressive chronic periodontal disease were extracted to remove the possible source of BA. These findings excluded the possibility of direct spread of bacteria from the odontogenic infectious lesion to the intracranial cavity. After extraction, there was no relapse of BA.

FDG-PET may predict the effectiveness of hyperbaric oxygen therapy in a patient with bisphosphonate-related osteonecrosis of the jaw: report of a case.

We report an advanced case of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in an osteoporotic patient treated with oral risedronate sodium for 2 years. An 80-year-old woman presented to our hospital complaining of pain, swelling and pus discharge in the lower alveolar ridge. Fluorine-18 labeled fluorodeoxyglucose positron emission tomography (FDG-PET) and bone scintigraphy showed definite uptake in the mandible. Under clinical diagnosis of BRONJ, we applied systematic treatments including antibiotic therapy, irrigation, cessation of bisphosphonate, hyperbaric oxygen (HBO) therapy, and debridement of necrotic bone. After pre-operative 20 sessions of HBO therapy, her clinical symptoms disappeared. SUVmax of FDG-PET decreased definitely from 4.5 to 2.5, although magnetic resonance image and bone scintigraphy did not show remarkable changes. After minor surgery with debridement of necrotic bone, she received another ten sessions of HBO therapy. After the treatment, her clinical course was excellent. In conclusion, this report demonstrates FDG-PET may predict the effect of HBO therapy in BRONJ.

Monitoring indices of bone inflammatory activity of the jaw using SPECT bone scintigraphy: a study of ARONJ patients.

Development of quantitative analysis software has enabled application of several standardised uptake values (SUV) for bone analysis in single photon emission computed tomography (SPECT). The present retrospective study aimed to develop a reliable method of monitoring bone inflammatory activity in antiresorptive agent-related osteonecrosis of the jaw (ARONJ) using SPECT quantitative analysis software. Fifteen ARONJ patients underwent SPECT before and after anti-inflammatory therapy. We calculated the mean maximum SUV (SUVmax) of the bilateral cranial bones using quantitative analysis software and used this as the control [C]. We attempted to adjust the SUVmax of the lesion [L] as follows: adjusted SUVmax (aSUVmax) = [L] - [C]. The optimum threshold to calculate the metabolic bone volume (MBV) (cm3) was [C] + 3. The threshold values obtained for each case were input to calculate MBV at each osteomyelitis site. Retrospectively, we compared aSUVmax and MBV of each patient's ARONJ before and after anti-inflammatory therapy. The patients' high aSUVmax or large MBV of the ARONJ reduced rapidly, reflecting individual clinical findings after treatment. Application of SPECT quantitative analysis software to monitor bone inflammatory activity in ARONJ could improve the prognosis-deciding abilities of clinicians and enable them to treat ARONJ effectively.

Quantitative bone single photon emission computed tomography analysis of the effects of duration of bisphosphonate administration on the parietal bone.

Effects of long-term bisphosphonate (BP) administration on the metabolism of healthy bone and the concomitant changes in imaging are unclear. Hence, we aimed to retrospectively investigate the effects of long-term BP administration on the intact parietal bone using the standardised uptake value (SUV) derived from single photon emission computed tomography (SPECT). We enrolled 29 patients who had odontogenic infection, osteoporosis, bone metastasis cancer, or rheumatoid arthritis, and classified them into BP-naïve: A (14 patients) and BP-treated: B, < 4 years (7 patients) and C, ≥ 4 years (8 patients) groups. We measured the maximum bilateral SUV (SUVmax) of the parietal bone using quantitative bone SPECT software. There were significant differences in the duration of BP administration and SUVmax of the parietal bone among the diseases (P < 0.0001 and P = 0.0086, respectively). There was a positive correlation between the duration of BP administration and SUVmax of the parietal bone (rs = 0.65, P = 0.0002). The SUVmax was significantly different between A and B (P = 0.02) and between A and C (P = 0.0024) groups. This is the first report on the correlation between long-term BP administration and the SUVmax of the parietal bone using the quantitative bone SPECT analysis.

Imaging modalities for drug-related osteonecrosis of the jaw (3), Positron emission tomography imaging for the diagnosis of medication-related osteonecrosis of the jaw.

Medication-related osteonecrosis of jaws (MRONJ) is one of the most complicated inflammatory conditions in oral and maxillofacial region. It is very difficult to correctly evaluate the degree and extent of necrosis and infection. This refractory osteonecrosis often needs extended surgery, leading to impaired quality-of-life. We have performed hyperbaric oxygen therapy (HBO) combined with conservative surgery for advanced cases. We have appraised the value of FDG-PET and 3-phase bone scintigraphy in the diagnosis and management of this condition. MRONJ showed significantly higher SUVmax on FDG-PET than the others. Although the 3 phase pool bone images did not change significantly, perfusion and static bone image as well as PET showed remarkable response to HBO for MRONJ. SUVmax after HBO was significantly lower than those of before HBO. These preliminary results indicate that FDG-PET is useful for monitoring the effect of HBO for MRONJ.