OBJECTIVE: To evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 (⁶⁷Ga) citrate scintigraphy. MATERIALS AND METHODS: We studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of ^99mTc-EDDA-HYNIC-TOC, and 21 after injection of ¹¹¹In-DTPA-octreotide. All patients also underwent ⁶⁷Ga citrate imaging, except for one patient who died before the ⁶⁷Ga was available. RESULTS: In 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by ⁶⁷Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than ⁶⁷Ga uptake in 11 of the 20 patients with positive images and similar to ⁶⁷Ga uptake in the other 9 patients. The only patient who did not undergo ⁶⁷Ga scintigraphy underwent ^99mTc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis. CONCLUSION: SPECT/CT with ^99mTc-EDDA-HYNIC-TOC or ¹¹¹In-DTPA-octreotide seems to be a good alternative to ⁶⁷Ga citrate imaging for the evaluation of patients with systemic granulomatous disease.

Keywords: Single photon emission computed tomography; X-ray computed tomography; Octreotide; Gallium-67; Tuberculosis; Paracoccidioidomycosis.