Analysis of the Density Characteristics of Giant Cell Bone Tumors Treated with Denosumab According to CT Findings

Abstract

Background: Giant cell tumor of bone (GCTB) is a relatively common benign bone tumor, accounting for 4–9.5 % of all primary bone neoplasms. Localization of GCTB is one of the most important differential diagnostic criteria, since the tumor affects certain parts of the skeleton. Until now, surgical treatment was considered the method of choice in the treatment of GCTB. However, in recent years, denosumab, a genetically engineered drug, has been widely used to treat this tumor. Denosumab treatment of GCTB prevents further tumor progression and reduces tumor size. Histological examination of the surgical specimen is undoubtedly the most objective method for assessing the effectiveness of the treatment. However, it is sometimes necessary to get information regarding the effectiveness of conservative therapy.Purpose: To analyze the density characteristics of denosumab-treated GCTB using CT densitometry.Material and methods: The study included 15 patients aged 28–59 years with histologically verified giantcell tumor, who received denosumab treatment followed by surgery. Tumor structure was assessed before starting denosumab therapy, after 3 and 6 courses of denosumab therapy.Results: Changes in the density parameters (the mean tumor density, standard deviation of density, increase in the median tumor density and standard deviation of density, index of the relative density of the tumor) measured by CT images were analyzed. These changes were statistically significant in GCTB patients before initiating therapy with denosumab, and after 3 and 6 courses of denosumab therapy.Conclusion: Thus, CT densitometry is a useful tool for assessing the density characteristics of the tumor in GCS patients treated denosumab.