Comparison between radiotherapy and neoadjuvant denosumab followed by surgery in the treatment of giant cell tumor of bone: A retrospective observational study

Background: Giant cell tumor is a locally aggressive tumor of the bone. In the predenosumab era, treatment comprised surgery or radiotherapy in potentially resectable lesions. After the advent of denosumab, utilizing neoadjuvant denosumab followed by surgery has emerged as an effective treatment option. Objectives: We aimed primarily to assess and compare the locoregional failure-free survival of patients with giant cell tumor of the bone (GCTB) treated with either external beam radiotherapy or neoadjuvant denosumab followed by surgery. The secondary objective was to assess and compare the quality of life (QoL) of patients between the two arms. Materials and Methods: In this single institutional retrospective study, conducted between August 2022 and August 2023 in the Department of Radiotherapy in the Institute of Post Graduate Medical Education and Research and SSKM Hospital Kolkata, West Bengal, India, we included patients with histopathologically proven GCTB. These patients were treated with either radiotherapy (54 Gray in 27 fractions) or neoadjuvant denosumab (for 8 doses) followed by surgery and were followed up at least for 6 months after completing the first-line therapy. Patients were monitored every 3 months for 2 years and then every 6 months thereafter. Locoregional control of the tumor was assessed by clinical examination and imaging. QoL was assessed and compared by the EQ-5D-5L questionnaire and health today scoring system. Results: We enrolled 22 patients in the radiotherapy alone group and 26 patients in the group receiving neoadjuvant denosumab followed by surgery. The 5-year locoregional failure-free survival was achieved in 18/22 patients (81.8%) in the radiotherapy arm and in 20/26 patients (76.9%) in the neoadjuvant denosumab group (P, 0.680). There was no significant difference in the QoL between the two groups of patients (P, 0.850). Conclusion: Radiotherapy and neoadjuvant denosumab followed by surgery result in similar locoregional control and quality of life in the patients with giant cell tumor of bones, and both can be considered appropriate treatment options in patients with initially unresectable tumors.