99Tcm-MIBI scintigraphy for the assessment of preoperative chemotherapy response of osteosarcoma / 中华核医学杂志

ABSTRACT

Objective To investigate the value of 99Tcm-methoxyisobutylisonitrile (MIBI) scintigraphy in assessing the preoperative chemotherapy response and multidrug resistance of osteosarcoma.Methods From January 2007 to October 2008, 12 patients (female4, male8; mean age16.3 years,range8-27 years) underwent early (10min) and delayed (120 min) 99Tcm-MIBI scintigraphy before and after preoperative chemotherapy.Seven cases had osteosarcoma at the distal femurs, 2 at the proximal tibias, 2 at the upper end of humerus and 1 at the fibula.The tumor-to-background ratio (T/B) and washout rate (WR) were calculated.Tumor necrosis was classified according to Huvos criterion after limb salvage surgery.Immunohistochemical staining for P-glycoprotein(gp) was examined.Spearman correlation analysis and t-test were performed.Results According to Huvos criterion, 7 patients were classified as good responders with more than 90% of tumor cell necrosis and 5 as poor responders with less than 90% of tumor cell necrosis.R value (ratio of early phase T/B after and before chemotherapy) was significantly lower in good responders than that in poor responders (0.473 ± 0.21 vs 0.998 ± 0.06, t= 5.342, P= 0.000 ).R value was significantly correlated with the degree of tumor cell necrosis ( rs=- 0.87, P= 0.000 ).WR was significantly higher in patients with positive P-gp expression than that in patients with negative P-gp expression ((38.36 ±18.64)% vs (6.40±5.87)%, t= -3.278, P=0.008).There was significant correlation between the WR and P-gp expression (rs = 0.91, P= 0.001 ).Conclusion 99Tcm-MIBI scintigraphy is a feasible non-invasive technique to assess the chemotherapy response and to detect P-gp expression of osteosarcoma.