The Use of Neo – Adjuvant Denosumab in Treatment of Giant Cell Tumours of the Spine

Abstract

Abstract Background The current recommended treatment for Giant Cell Tumour of the spine is en bloc excision. Denosumab is a monoclonal RANKL inhibitor that shows promising results when used as a neo – adjuvant treatment. The purpose of this study was to assess the effect of Denosumab on tumour characteristics and symptom relief. Methods We performed a retrospective review of 12 patients treated with denosumab as neo adjuvant and stand - alone treatment. Tumour volume and PET SUV capitation measurements were taken before and after treatment and patients were interviewed for subjective pain responses. Clinical response was determined by reduction in tumour volume, PET SUV capitation, the Boriani calcification response classification, improvement in the Bilsky epidural grading and WBB layers and improvement in pain. Results Following treatment 75% of patients were pain free with 58% noting improvement within 48 hours. Mean relative volumetric reduction in tumour volume was 42%. All pathology specimens confirmed elimination of giant cells. Improvement in Bilsky epidural disease grading occurred in 7/12 cases. Median baseline SUVmax was 14.7 and post treatment was 3.3. Sixty - seven percent of patients demonstrated intralesional bone formation following treatment. At one year follow-up, there were no cases of local disease recurrence, malignant transformation or metastases. Conclusions This study demonstrates neo-adjuvant denosumab can facilitate en bloc resection by reducing the tumour burden around critical adjacent neurovascular structures, reducing the risk morbidity and improving preoperative pain. We recommend routine use when W-B-B – based criteria are fulfilled for en – bloc excision.