Sequential Imaging Characteristics and Potential Role of F18 Fluorodeoxyglucose Positron Emission Tomography/CT in the Evaluation of Treatment Response in Cases of Spinal Tuberculosis Without Neurological Involvement: Results From a Pilot Study

Purpose In this non-randomized study, we prospectively studied the sequential imaging properties of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and evaluated the role of FDG PET as a non-invasive imaging modality for identifying non-responders during anti-tubercular treatment (ATT) of spinal tuberculosis (TB). Methods Before starting anti-tubercular treatment, 25 patients with clinically and radiological suspected; pathologically confirmed spinal TB had a pretreatment contrast-enhanced whole-body FDG PET scan, followed by scans at six, 12, and 18 months. The maximum standardized uptake value (SUVmax) was computed, and the mean change in SUVmax was compared. The mean change in SUVmax was correlated with the clinicoradiological improvement. Result In cases of spinal tuberculosis, the FDG PET scan can help identify extra-spinal and non-contagious involvement. In our 25 cases of spinal TB, the baseline peak SUVmax of lesions ranged from 6.3 to 28.5 (mean 14.8). Despite treatment, the condition progressed in two patients, and they had neurological deficits; in both cases, the SUVmax levels increased. The fall in SUVmax during the treatment course was statistically significant (p-value <0.05) and correlated well with the clinical improvement. Conclusion The inflammatory cells show increased uptake of F18 FDG, so uptake of radioactive tracer localizes and quantifies the disease activity; thus, FDG PET/CT holds a promising role as a sensitive non-invasive modality for the detection, staging, assessing disease activity, and monitoring therapy and deciding end point treatment in spinal TB.