Diagnostic performance of whole-body SPECT/CT in bone metastasis detection using 99m Tc-labelled diphosphate: a systematic review and meta-analysis

To evaluate the diagnostic performance of whole-body (WB) integrated single photon emission tomography (SPECT)/computed tomography (CT) in detecting bone metastasis (BM) and to investigate whether WB-SPECT/CT offered any additional benefit value compared to planar bone scintigraphy (PBS) with Tc-hydroxy-methylene diphosphonate or Tc methylene diphosphonate. Medline, EMBASE, SCOPUS, Web of Science, and CINAHL were searched systematically up to 28 August 2019. All studies using histopathological analysis and/or follow-up imaging and clinical data as the reference standard were eligible for inclusion. Eleven studies (1,611 patients) were analysed. Based on patient analysis, the sensitivity, specificity, and area under the curve (AUC) of WB-SPECT/CT were 92% (92% confidence interval [CI], 89-95%), 95% (95% CI, 94-96%), and 0.9835, respectively, in the case of negative equivocal findings for BM, and 94% (95% CI, 91-96%), 94% (95% CI, 92-95%), and 0.9790, respectively, when regarded positive. On a lesion basis, these parameters were 91% (95% CI, 89-94%), 96% (95% CI, 94-97%), and 0.9906, respectively, in the case negative equivocal findings, and 92% (95% CI, 89-94%), 95% (95% CI, 94-97%), and 0.9898, respectively, when regarded positive. Comparing 1,265 patients from eight studies, higher sensitivity (92% versus 74%, p=0.04) and specificity for WB-SPECT/CT against PBS (93% versus 80%, p=0.01) in the case of positive equivocal findings; however, when regarded negative, WB-SPECT/CT demonstrated higher sensitivity (91% versus 70%, p=0.01), but no significant difference was apparent in specificity (94% versus 89%, p=0.07). Compared to PBS, WB-SPECT/CT had superior diagnostic accuracy in BM detection and exhibited a more reliable performance with less equivocal results.