Bone scan index on bone scintigraphy and radiation therapy for bone metastases from cancers other than prostate and breast cancers: A retrospective observational study.

Abstract

In this study, we aimed to use new automatic analysis software (VSBONE bone scan index (BSI); Nihon Medi-Physics, Tokyo, Japan) to investigate whether the pre-radiation therapy (RT) BSI, derived from bone scintigraphy (BS) images, is a prognostic indicator in patients undergoing RT for bone metastases from cancers other than breast or prostate cancer. In this retrospective single-institution study, we analyzed data of 51 patients who had undergone whole-body scintigraphy before receiving RT for bone metastases from cancers other than breast and prostate cancer between 2013 and 2019. Their bone metastases preradiation BSI were automatically calculated using newly developed software (VSBONE BSI; Nihon Medi-Physics, Tokyo, Japan). Univariate and multivariate analyses were performed to identify associations between selected clinical variables and overall survival (OS). We did not find a significant association between BSI and OS. However, we did find that younger patients had significantly better OS than older patients (P = 0.016 and P = 0.036, respectively). In addition, BSI were significantly lower in patient with solitary or osteolytic bone metastases than in those with osteoblastic or mixed bone metastases (P = 0.035 and P ≤ 0.001, respectively), and significantly higher in those with lung cancer than in those with other types of cancer (mean BSI 3.26% vs. 1.97%; P = 0.009). The only significant association with survival identified in this study was for age at the time of BS and at time of diagnosis of bone metastases.