Influence on Therapeutic Decision Making of SPECT-CT for Different Regions of the Foot and Ankle

BACKGROUND Single-photon emission computed tomography and computed tomography (SPECT-CT) has a high impact on diagnosis and treatment decision of different joints. The aim of this study was to evaluate whether there is a different gain of SPECT-CT for different foot regions. MATERIAL AND METHODS We retrospectively identified 86 patients who received a SPECT-CT of the foot and ankle between April 2011 and December 2012. We divided all patients into the following subgroups: ankle (group 1), subtalar (group 2), Chopart (group 3), and Lisfranc (group 4). The local ethical committee approved the study. RESULTS The clinical treatment decision was changed based on SPECT-CT results in 64.5% of group 1, 65.2% of group 2, and 75% each of groups 3 and 4. Eighty patients (93%) had pain relief after treatment based on SPECT-CT. The overall SPECT-CT sensitivity was 0.94 and the specificity was 0.57. The positive and negative predictive values were 0.87 and 0.75, respectively. CONCLUSION The impact of SPECT-CT on treatment decision is slightly higher in diseases of the Chopart and Lisfranc joints than in the upper ankle and subtalar joints. The additional information has a clinical relevance due to the high rate of pain relief by treatment based on SPECT-CT diagnosis.