骨巨细胞瘤（GCTB）是一种局部侵袭性中间骨肿瘤。狄诺塞麦 (Denosumab) 在 GCTB 治疗中显示出有效性；然而，地诺塞麦降级治疗不可切除的 GCTB 的益处尚未得到充分讨论。本研究调查了狄诺塞麦降级治疗 GCTB 的有效性和安全性。回顾性分析了 2014 年 4 月至 2021 年 12 月期间在冈山大学医院（日本冈山）接受降级地诺塞麦治疗的 9 例不可切除的 GCTB 或不符合切除条件的可切除的 GCTB 患者的病历。狄诺塞麦治疗间隔逐渐延长至每8周、12周和24周一次。对标准和降级狄诺塞麦治疗期间的影像学变化和临床症状进行了评估。标准 4 周治疗的中位时间为 12 个月后，狄诺塞麦间隔时间逐渐降低。影像学显示，每周 4 周的治疗获得的溶骨性病变的再骨化在每周 8 周和 12 周的治疗中得以维持。标准治疗后骨骼外质量显着减少，而降级治疗期间肿瘤持续减少。在24周的治疗过程中，2名患者病情稳定，2名患者出现局部复发。标准治疗后临床症状显着改善，并在降级治疗期间保持改善。严重不良事件包括颌骨坏死（2例）、非典型股骨骨折（1例）和GCTB恶变（1例）。总之，对于不可切除的 GCTB 患者，每周 12 周的降级地诺塞麦治疗显示出作为维持治疗的临床益处，此外，标准治疗还可以持续稳定的肿瘤控制和改善的临床症状。也可以进行每周 24 周的治疗，并特别注意检测局部复发。版权所有 © 2024，Spandos Publications。

Giant cell tumor of bone (GCTB) is a locally aggressive intermediate bone tumor. Denosumab has shown effectiveness in GCTB treatment; however, the benefits of denosumab de-escalation for unresectable GCTB have not been well discussed. The present study investigated the efficacy and safety of denosumab de-escalation for GCTB. The medical records of 9 patients with unresectable GCTB or resectable GCTB not eligible for resection, who received de-escalated denosumab treatment at Okayama University Hospital (Okayama, Japan) between April 2014 and December 2021, were retrospectively reviewed. The denosumab treatment interval was gradually extended to every 8, 12 and 24 weeks. The radiographic changes and clinical symptoms during standard and de-escalated denosumab therapy were assessed. The denosumab interval was de-escalated after a median of 12 months of a standard 4-weekly treatment. Imaging showed that the re-ossification of osteolytic lesions obtained with the 4-weekly treatment were sustained with 8- and 12-weekly treatments. The extraskeletal masses reduced significantly with standard treatment, while tumor reduction was sustained during de-escalated treatment. During the 24-weekly treatment, 2 patients remained stable, while 2 patients developed local recurrence. The clinical symptoms improved significantly with standard treatment and remained improved during de-escalated treatment. There were severe adverse events including osteonecrosis of the jaw (2 patients), atypical femoral fracture (1 patient) and malignant transformation of GCTB (1 patient). In conclusion, 12-weekly de-escalated denosumab treatment showed clinical benefits as a maintenance treatment in patients with unresectable GCTB, in addition to sustained stable tumor control and improved clinical symptoms with standard treatment. A 24-weekly treatment can also be administered, with careful attention paid to detecting local recurrence.Copyright © 2024, Spandidos Publications.