Technical feasibility, radiation dosimetry and clinical use of 18 F-sodium fluoride (NaF) in evaluation of metastatic bone disease in pediatric population.

PURPOSE: The role of 18 F-fluoride (18 F-NaF) PET-CT for the detection of bone metastases in adults is well established and is considered superior to conventional bone scintigraphy. However, data pertaining use of 18 F-NaF PET-CT in pediatric oncology is relatively sparse. The aim of the present study is to retrospectively analyze and share a single-center experience of 18 F-NaF PET-CT in pediatric population and to provide preliminary information regarding imaging technique, feasibility of this modality in young patients and radiation dosimetry measurements in pediatric oncology cases.

MATERIALS AND METHODS: Twenty-four pediatric patients (mean age 8.0 ± 3.9) were included in the study for retrospective analysis. All patients were referred for primary staging or restaging for potential osseous metastatic disease and PET-CT scan was performed by injecting 2.2 MBq/kg (0.06 mCi/kg) of 18 F-NaF.

RESULTS: Nine patients were imaged for primary staging and in all cases increase osteoblastic activity was seen in the primary tumor and of these, metastatic bone disease was identified in 2/9 patients. In the restaging group comprising 15/24 patients, metastatic deposits were identified in 3/15 whilst no disease was seen in the remaining 12 patients. Patients were injected a mean dose of 90.35 ± 22.9 MBq with an estimated mean effective absorbed doses of 2.98 ± 0.75 mSv for 18 F-NaF and 3.37 ± 2.4 mSv for CT alone. Mean cumulative effective dose of 18 F-NaF PET-CT scan was 5.11 ± 2.7 mSv.

CONCLUSIONS: 18 F-NaF PET-CT may be a feasible alternative to 99m Tc MDP for radionuclide bone scintigraphy in the evaluation of pediatric bone pathology. Due to its better pharmacokinetics, there is potential that osseous staging can be achieved with relatively low doses and with a similar radiation burden as with 99m Tc-MDP imaging.