Value of SPECT/CT imaging for follow-up of bone metastases

Objective To retrospectively evaluate the value of SPECT/CT imaging for follow-up of bone metastases.Methods A total of 178 patients with bone metastases (387 lesions) underwent 2 or more events of whole-body bone scintigraphy (WBS) and SPECT/CT imaging.Sequential images were analyzed by 2 experienced,nuclear medicine physicians.Each lesion was interpreted as progressive,remissive or stable in WBS or SPECT/CT independently.Reasons for the discordance between WBS and SPECT/CT results were analyzed.The results of clinical follow-up,including clinical symptoms,tumor markers,serum ALP,radiograph,CT and MRI,were likewise classified as progressive,remissive or stable.The x2 test was used to compare the differences between the two imaging methods.Results The follow-up results of the two imaging methods were consistent in 313 (80.88％,313/387) lesions,including 208 in progression and 105 in remission or stable condition.Among the 74(19.12％,74/387) lesions showing discordance,48 showed remission or stable conditions on WBS but progression on SPECT/CT (64.86％,48/74) ; while 26 showed progression on WBS but remission or stable condition on SPECT/CT (35.14％,26/74).There was a statistically significant difference of the follow-up results between WBS and SPECT/CT (x2 =6.54,P ＜0.05).Conclusion SPECT/CT is more valuable than WBS for follow-up of bone metastases. Key words: Neoplasm metastasis ;  Skeleton ;  Tomography, emission-computed, single-photon ; Tomography, X-ray computed;  MDP