Role of three-phase bone scintigraphy in paediatric osteoid osteoma eligible for radiofrequency ablation.

Objective: The objective of the study was to underline the importance of three-phase bone scintigraphy at the time of diagnosis in children with suspected osteoid osteoma (OO) who are eligible for radiofrequency ablation.

Methods: Fifty-three patients (13 girls; mean age 7.2 years, 20% younger than 10 years of age) who underwent bone scintigraphy for suspected OO between 2005 and 2010 were included in the study, of whom 46 underwent a radiography at diagnosis. Computed tomography-guided biopsy was performed in all patients after bone scintigraphy, and radiofrequency ablation was performed following biopsy in patients with OO; ablation efficacy was confirmed by MRI at 1, 3, 12 and 18 months.

Results: The radiographic results were negative in 27/46 patients and was unclear in 19. Bone scintigraphy showed lesions in 53/53 patients, of whom 51 patients had a typical pattern of osteoma and nine patients required an additional scan with a pinhole collimator. Histological examination showed OO in 51/53 patients (3/51 intramedullary), Ewing's sarcoma in 1/53 patients, and chronic osteomyelitis in 1/53 patients.

Conclusion: Any child with recurrent nocturnal pain and/or limb swelling should undergo radiography of the involved skeletal segment, which is the first-choice diagnostic method in the clinical suspicion of OO. In the event of ambiguous or negative radiographic results, bone scintigraphy is needed to exclude other pathologic conditions and to confirm the diagnosis. In children with recurrent but not well-localized bone pain in which OO is strongly suspected for signs and symptoms, a bone scan can help detect the lesion. The diagnostic accuracy of the bone scan, particularly for the appendicular skeleton, can be improved by pinhole collimator acquisition.