Also, bone scans actually measure bone formation, not the presence of cancer itself.
Kim et al. used coated zirconia scaffolds to augment calvarial defects in a rabbit model and reported closely matching values regarding porosity and density of the prepared scaffolds and regarding the amount of newly measured bone formation [20].
To measure bone formation rates, mice were injected ip with 30 µg/g body weight of tetracycline 7 and 2 d before they were killed.
Computed tomography (CT) was used to evaluate bone formation and to measure the quantity of bone formation: Alonso et al. [ 25] performed a CT at 6 and at 12 months postoperatively, Dickinson et al. [ 26] performed a CT at 6 months postoperatively and Herford et al. [ 27] performed a CT at 4 months postoperatively.
To assess bone formation and bone resorption, we measured the currently available most sensitive and specific biochemical markers (Garnero and Delmas, 2003).
Bone-specific alkaline phosphatase (bALP) and osteocalcin (OC) were measured as bone formation indices.
Serum bone alkaline phosphatase (BAP) (the reference range in postmenopausal women 3.8 22.6 μg/L) and N-terminal propeptide of type 1 procollagen (P1NP) (the reference range in postmenopausal women 27.0 109.3 ng/mL) were measured as bone formation markers using a chemiluminescent enzyme immunoassay and an antibody radioimmunoassay, respectively.
Importantly, the present results regarding BTM should not be extrapolated to any possible effect of TNF-α blocking therapy on radiographic progression in AS since no imaging method was used to measure new bone formation resulting in the formation of syndesmophytes and joint ankylosis.
To measure dynamic bone formation parameters, mice were injected intraperitoneally with calcein (Sigma, St Louis, MO, USA; 30 mg/kg body weight) and xylenol orange (Sigma, St Louis, MO, USA; 90 mg/kg body weight) on day 9 and day 2 before tissue harvest.
Additional measures of bone formation were not attempted, as our previous studies have found a high degree of correlation between micro-CT measured bone volumes and bone areas measured by histomorphometry.
