Objective To evaluate the value of semiquantitative analysis of whole body bone imag-ing on distal femoral metaphysis osseous metastasis of neuroblastoma.

Methods Twenty-nine patients with confirmed neuroblastoma by pathological reports were divided into group of metastasis and group of no metastasis by bone marrow slides, X-ray, CT, MRI or clinical follow-up. Whole body bone imaging was performed pre-or postoperation. All cases were analysed by two methods: ①Semi-quantitative analysis: Regions of interest on bilateral distal femoral metaphysic and middle of femoral were drawn, and their average counts were measured. The ratio of radioactivity of distal femoral metaphysic to middle of femoral was calculated; ②Visual analysis: Bilateral distal femoral metaphysic metastasis were diagnosed by visual analysis according to whole body bone imaging. The differences between this two= Methods were compared.

Results There were differences of the ratio of radioactivity of distal femoral metaphysic to middle of femoral between group of metastasis and group of no metastasis(t=8.334, P < 0.01), and there was no significant difference betweent the two methods(χ²=0.68, P > 0.05). The sensitivivy, specificity, accuracy, positive predictive value and negative predictive value of semiquantitative analysis in detecting osseous metastasis were 90.5%, 95.7%, 94.4%, 86.4% and 97.1%, while visual analysis were 81%, 100%, 95.6%, 100% and 94.5%.

Conclusions Radionuclide whole body bone imaging was of great importance in diagnosis of osseous metastasis of neuroblastoma. The diagnostic accuracy was improved by combination of visual analysis and semi-quantitative analysis.