1420. 99mTc-Ethambutol scintigraphy with SPECT/CT in skeletal tuberculosis: A Prospective Study

Abstract Background Tuberculosis (TB) is the most common infectious disease in poor and underdeveloped countries, with extra-pulmonary TB (EPTB) infections accounting for 10-15 percent of all cases in developing and underdeveloped countries. Apart from 18F-FDG PET/CT, which cannot discriminate between metastatic and infective lesions, Nuclear Medicine methods do not play a significant role in clinical practice. We have attempted to address this constraint by our study involving radiolabelled Ethambutol. Methods The study was conducted over a period of 20 months at the Department of Nuclear Medicine of our institution and included a prospective cohort of 16 adult patients diagnosed as skeletal TB (clinico-radiologically, histopathologically, or microbiologically) who were treatment naive or within 14 days of treatment initiation. 10-15 mCi of Tracer was administered to the patients. Dynamic phase imaging was performed for 10 minutes, followed by minimum 3 planar anterior and posterior views whole-body scans with over 4 hours. SPECT/CT was performed between 60-120mins after injection. Patients were followed up by a clinical assessment/telephonic review with a follow up period of 2 months to 21 months (mean follow up period of 10.2 months). Results SPECT-CT and 99mTc-Ethambutol scintigraphy were performed on 16 patients at the time of diagnosis or treatment initiation. The average age of individuals with positive scans was 33.75, whereas those with negative scans was 36.25 +/- 19.80. The most common symptom was bone pain (93.75%), followed by fever (81.25%) and weight loss (13 of 16 cases) (81.25 percent ). 3/12 (25%) of the 12 positive patients had multiple site involvement, whereas 8/12 (75%) had single site involvement. We found considerable tracer uptake in 75% of the patients in the trial. When ATT was given to 11/12 (92%) of the people who had a positive scan, the clinical result was decreased discomfort and greater mobility in the affected joints. Conclusion 99mTc-ethambutol scintigraphy with SPECT/CT was accurately able to show bony lesions in 75% of the patients. Also 92% of those with positive scan eventually responded to Anti-Tubercular Treatment thus showing that this rarely used technique may have a role in prognosticating skeletal tuberculosis. Disclosures All Authors: No reported disclosures.