PET/CT features of extrapulmonary tuberculosis at first clinical presentation: a cross-sectional observational¹⁸F-FDG imaging study across six countries

Abstract

BackgroundA large proportion of the huge global burden of extrapulmonary tuberculosis (EPTB) cases are treated empirically without accurate definition of disease sites and extent of multi-organ disease involvement. Positron emission tomography (PET) imaging using 2-deoxy-2-(fluorine-18) fluoro-d-glucose (18F-FDG) in tuberculosis could be a useful imaging technique for localising disease sites and extent of disease.MethodsWe conducted a study of HIV-negative adult patients with a new clinical diagnosis of EPTB across eight centres located in six countries: India, Pakistan, Thailand, South Africa, Serbia and Bangladesh, to assess the extent of disease and common sites involved at first presentation. 18F-FDG PET/computed tomography (CT) scans were performed within 2 weeks of presentation.Findings358 patients with EPTB (189 females; 169 males) were recruited over 45 months, with an age range of 18–83 years (females median 30 years; males median 38 years). 350 (98%) out of 358 patients (183 female, 167 male) had positive scans. 118 (33.7%) out of 350 had a single extrapulmonary site and 232 (66.3%) out of 350 had more than one site (organ) affected. Lymph nodes, skeleton, pleura and brain were common sites. 100 (28%) out of 358 EPTB patients had 18F-FDG PET/CT-positive sites in the lung. 110 patients were 18F-FDG PET/CT-positive in more body sites than were noted clinically at first presentation and 160 patients had the same number of positive body sites.Interpretation18F-FDG PET/CT scan has potential for further elucidating the spectrum of disease, pathogenesis of EPTB and monitoring the effects of treatment on active lesions over time, and requires longitudinal cohort studies, twinned with biopsy and molecular studies.

[18F]FDG Positron Emission Tomography for Initial Staging and Healing Assessment at the End of Therapy in Lymph Nodes and Bone Tuberculosis

“…The sensitivity of [ 18 F]FDG-PET/CT at initial diagnosis in our study is comparable to those previously reported (97-100%) (8,9,(12)(13)(14). Additional unknown injured sites were discovered on PET1 in 52.7% of cases.…”

“…Such parameter is highly variable in the literature, from 10 to 69%, probably depending on the study population (disseminated or local tuberculosis). Discovered additional sites mainly concerned cutaneous lesions, liver lesions and abdominal lymph nodes not detected on CT. As compared to data of the literature (8,9,(12)(13)(14), the percentage of residual [ 18 F]FDG uptake in lesions at the end of antibiotherapy is higher in our study (82 vs. about 40-50% in most studies). This may be explained by the characteristics of the study population: only extra-pulmonary and mostly disseminated tuberculosis in our study when other studies included both pulmonary and other types of tuberculosis.…”

Clinical and Imaging Features of Adults with Recurrent Pulmonary Tuberculosis - A Prospective Case-Controlled Study

“…CT or PET Scans can identify more cases of extra-pulmonary TB and can detect cryptic changes which may not be visible on chest X-rays. However these imaging facilities are not available (PET) or not accessible for TB diagnosis in our country and many resoource poor regions (Bomanji et al, 2020a;Bomanji et al, 2020b). Our study found that alcohol users were two times more likely to have RPTB in univariate analysis (cOR 1.93, 95% CI (1.19 -3.15) p < 0.001) but was not significant in multivariate analysis.…”

Towards more accurate 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging in active and latent tuberculosis

“…18 F-FDG PET/CT, as a whole-body imaging method, has the advantage of localizing and monitoring the response to therapy in extrapulmonary TB when there is no pulmonary involvement and in identifying additional extrapulmonary sites of disease in TB. 18 F-FDG uptake can occur in sites such as the liver, abdominal lymph nodes, and bones (Figures 2 and 3), or diffusely in the spleen as a sign of active infection (Vorster et al, 2014;Rodriguez-Takeuchi et al, 2019;Bomanji et al, 2019). FDG PET/CT might also be useful to identify extrapulmonary involvement of the central nervous system, but MRI is considered superior in this setting (Vorster et al, 2014;Rodriguez-Takeuchi et al, 2019;Bomanji et al, 2019;Gupta et al, 2009;Chaudhary et al, 2017).…”