Quantitative bone SPECT/CT for evaluating treatment response in patient with sternoclavicular arthritis

We report here a case of sternoclavicular arthritis due to SAPHO syndrome in a 60-year-old female in which quantitative values determined using bone SPECT/CT were useful to evaluate response. After celecoxib and alendronate sodium hydrate therapy, the chief complaints were well relieved and post-treatment Tc-99m HMDP bone SPECT/CT examination showed decreased uptake. The maximum standardized uptake value (SUV), peak SUV, mean SUV, metabolic bone volume, and total bone uptake of the untreated lesion were 18, 16, 10, 17 mL, and 180, respectively, which were decreased to 8, 7, 5, 15 mL, and 75, respectively, after the treatment. In comparison with pre-treatment situation, those parameters were decreased by -56%, -56%, -50%, -12%, and -58%, respectively, following celecoxib and alendronate sodium hydrate therapy, likely reflecting treatment response. Quantitative bone SPECT/CT may be useful to evaluate joint inflammatory activity and treatment response in a patient with osteoartritis.