What is the role of positron emission tomography in osteonecrosis of the jaws?

Purpose: Bisphosphonate-related osteonecrosis of the jaw (BP-ONJ) has become an associated side effect of BP therapy and several imaging modalities have been studied to show an ability to detect clinical disease. Because most patients at the authors' university hospital who develop BP-ONJ also undergo concurrent positron emission tomographic (PET) scanning, the authors investigated the utility of PET scans for diagnosis of BP-ONJ.

Patients And Methods: A retrospective chart review was performed of patients whose PET scans were acquired within 1 year of their BP-ONJ diagnosis (1998 through 2006). BP-ONJ was defined as intraoral exposure of the maxilla or mandible in patients on BPs and not given radiation to that area. This was performed at a university hospital with oncologic patients treated with BPs. All PET scans in this study were secondarily reviewed by a single expert reader for internal consistency (T.B.B.). A detailed timeline of the course of BP-ONJ was constructed by the review of medical records for each patient and the relation of each patient's PET scan results to that patient's BP-ONJ disease was evaluated. Data analysis was a descriptive analysis of PET scan findings in this patient population.

Results: Of the 25 patients studied, 5 were excluded for insufficient clinical or radiologic data. Of the 20 remaining patients (16 male, 4 female), 46 PET scans were performed and showed 53 areas of enhancement. Many patients had multiple PET scans performed while experiencing exposed bone, and 5 of these patients had alternating positive and negative scans with exposed bone, resulting in 13 patients with positive enhancement on a scan with exposed bone and 9 patients with no enhancement on a scan with exposed bone. Of the 13 patients with PET enhancement, 4 had signs of clinical infection documented at the time of examination. Sensitivity, specificity, and accuracy of PET scanning for BP-ONJ were 43%, 19%, and 62%, respectively. There were 7 patients with PET scans performed after clinical resolution of their exposed bone and 6 of those had no enhancement.

Conclusion: The purpose of this study was to report findings on PET scanning for patients with BP-ONJ. Although PET scans are useful in oncology, the present findings do not support their routine use for exclusively diagnosing or following cases of BP-ONJ.