In vivo imaging of prostate cancer involving bone in a mouse model

BACKGROUND. We compared the abilities of clinically relevant imaging modalities to quantify prostate cancer involving bone in a mouse model. Such non-invasive methods are needed pre-clinically to understand tumor biology and to evaluate therapy. METHODS. Human prostate cancer cells (MDA PCa 2b) or vehicle were injected into the right or left femur of SCID mice (n = 8). Radiography, computed tomography, and magnetic resonance imaging were performed 5 and 8 weeks later (n = 7). Bone scintigraphy (n = 6) was also performed at week 8. Imaging findings were compared with histology and correlated with contemporaneous serum prostate-specific antigen levels. RESULTS. Among the modalities evaluated, only MR imaging delineated prostate tumors involving bone. Tumor volume assessed by MR imaging correlated with PSA levels (R² = 0.87, P < 0.001). MR imaging of tumors corresponded with histology. Imaging of mineralized bone by CT corresponded with histology. CONCLUSION. In a mouse model, prostate tumors involving bone can be quantified using MR imaging.