Yonezawa Noritaka, Murakami Hideki, Kato Satoshi, Takeuchi Akihiko, Tsuchiya Hiroyuki
Department of Orthopedic Surgery, Kanazawa University School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8641, Japan.
Eur Spine J. 2017 May;26(Suppl 1):236-242. doi: 10.1007/s00586-017-5086-7. Epub 2017 Apr 10.
Denosumab, a novel monoclonal antibody that targets the receptor activator of nuclear factor-κB (RANK) ligand (RANKL), has recently been used to treat patients with giant cell tumor of bone (GCTB). However, few reports have described the clinical results of denosumab therapy for spinal GCTB and evaluated treatment efficacy with respect to the entirety of the resected vertebra after denosumab therapy.
We present the case of a 51-year-old man with T12 GCTB that was completely removed by a total spondylectomy following 10 courses of neoadjuvant denosumab therapy. Post-therapy radiological findings indicated epidural tumor reduction in the spinal canal and sclerotic rim formation. However, the affected vertebra collapsed despite denosumab therapy and a massive bridging callus formation was present between the spinal GCTB and adjacent vertebra.
These morphological changes made the tumor margins unclear and increased the difficulty of dissection of the segmental arteries from the vertebral body and en bloc corpectomy by a posterior-approach. Pathological findings indicated increased woven bone at the peripheral lesion of the resected vertebra and RANKL-positive stromal cells remained around the woven bone.
These findings support that GCTB stromal cells survived around the newly formed woven bone after long-term denosumab treatment and total surgical resection of such primary spinal lesions as the gold-standard treatment, even following administration of denosumab. Surgeons should note that prolonged adjuvant denosumab therapy may increase the difficulty of performing a posterior-approach total en bloc spondylectomy.
地诺单抗是一种靶向核因子κB受体激活剂（RANK）配体（RANKL）的新型单克隆抗体，最近已用于治疗骨巨细胞瘤（GCTB）患者。然而，很少有报告描述地诺单抗治疗脊柱GCTB的临床结果，并且没有评估地诺单抗治疗后整个切除椎体的治疗效果。
我们报告了一例51岁男性T12椎体GCTB患者的病例，该患者在接受10个疗程的新辅助地诺单抗治疗后，通过全脊椎切除术将肿瘤完全切除。治疗后的影像学检查结果显示椎管内硬膜外肿瘤缩小，并且形成了硬化边缘。然而，尽管进行了地诺单抗治疗，受累椎体仍发生塌陷，并且在脊柱GCTB与相邻椎体之间出现了大量的桥接骨痂形成。
这些形态学变化使肿瘤边界不清，增加了从椎体分离节段动脉以及通过后路整块椎体切除的难度。病理检查结果显示，切除椎体周边病变处的编织骨增多，并且在编织骨周围仍存在RANKL阳性的基质细胞。
这些研究结果支持，在长期使用地诺单抗治疗后，GCTB基质细胞在新形成的编织骨周围存活，并且即使在使用地诺单抗后，对于此类原发性脊柱病变，全手术切除仍是金标准治疗方法。外科医生应注意，延长辅助性地诺单抗治疗可能会增加后路整块全脊椎切除术的难度。
