title: Denosumab: non-surgical treatment option for selective arterial embolization resistant aneurysmal bone cyst of the spine and sacrum. Case report.
abstract: Aneurysmal Bone Cyst (ABC) is a cystic lesion of bone, occurring in 70% of cases as a primary lesion. Even if the metaphyseal region of long bones is more frequently involved, vertebral localization is not rare: ABC represents 15% of all primary spine and sacral tumours. Selective arterial embolization (SAE) represents the first treatment option for vertebral ABC. However, in few cases, multiple SAEs are not possible. The aim of this work is to report two cases of vertebral ABC unresponsive to SAE positively treated with Denosumab.
  
  
  
  Two patients affected by ABC of the lumbar spine were treated by SAE without any response. Thus, the patients were submitted to an off-label treatment with Denosumab, following the same protocol already used in case of Giant Cell Tumour (GCT): 120 mg once a week for 4 weeks consecutively, then once every 40 days.
  
  
  
  In both cases, patients resulted to be pain-free after 11-13 Denosumab administrations and CT scan showed almost complete ossification of the lesions.
  
  
  
  The two cases reported here are not conclusive but they may support the project of a prospective study to confirm the effectiveness of Denosumab in ABC treatment as an alternative to SAE.
authors.affiliation: Department of Oncological and Degenerative Spine Surgery, Istituto Ortopedico Rizzoli, Bologna, Italy. riccardoghermandi@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Ghermandi
authors.forename: S
authors.initials: S
authors.lastname: Terzi
authors.forename: A
authors.initials: A
authors.lastname: Gasbarrini
authors.forename: S
authors.initials: S
authors.lastname: Boriani
mesh_terms: D000293:Adolescent; D000328:Adult; D017824:Bone Cysts, Aneurysmal / Q000188:drug therapy*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D000069448:Denosumab; D006801:Humans; D008297:Male; D012447:Sacrum; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D000069448:Denosumab