Role of skeletal scintigraphy in soft tissue sarcoma: Improving the diagnostic yield

Background: The presence of skeletal metastases significantly influences the therapeutic strategy adopted for soft tissue sarcoma. However, literature on the prevalence of skeletal metastases in soft tissue sarcoma is limited and none of the available data is based on the Indian patient population. Aim: To determine the prevalence of skeletal metastases at presentation in patients of soft tissue sarcoma and to rationalise the use of preoperative skeletal scintigraphy in such patients. Methods and Material: Preoperative bone scans were evaluated in 122 patients with soft tissue sarcoma (median age, 34 years; range, 4-83). The scans were classified into 3 grades: Grade 1: metastases very likely; Grade 2: equivocal; Grade 3: normal or benign lesion. In all the patients studied, the ability of the patient to localize the site or sites of pain was recorded and that was correlated with the site of metastases in scintigraphy. Result: Seventeen (13.9%) patients had Grade 1 scan; 16 of them had bony pain that was not readily explainable by trauma or other local factors. Ten ( 8.1%) patients had Grade 2 scan, five of them had bony pain which was not readily explainable by trauma or other local factors. Ninety-five patients (77.8%) had Grade 3 scan. Of these, 9 had localised bone pain which could be definitely associated with trauma or joint degeneration. Conclusion: The prevalence of skeletal metastases at presentation in patients with soft tissue sarcoma is low (13.9%). The low rates of skeletal metastases in bone pain-free patients (0.9%) versus the high rate in symptomatic patients (76.1%) supports the use of bone scanning in symptomatic patients only

Does I-131-MIBG underestimate skeletal disease burden in neuroblastoma?

Background: Controversy persists as to the need for both MIBG and bone scanning in routine evaluation of neuroblastoma. Aim: To compare the efficacy of I-131- metaiodobenzylguanidine (MIBG) scan against that of conventional Tc99m- methylene diphosphonate (MDP) bone scan for the detection of skeletal deposition of neuroblastoma. Methods and Material: The study included 57 patients (36 boys, 21 girls: age range 1-14 years) of neuroblastoma who underwent both bone scan with Tc99m-MDP and I-131-MIBG scan within 15 days of each other at presentation and during follow-up. Results: At presentation 11(19.2%) patients had evidence of skeletal metastases on MDP scan against 7 patients who showed bony secondaries on MIBG scan. Of the 7 patients, with positive MIBG and MDP scans, MDP scan detected 11 sites whereas MIBG scan detected 7 sites. On follow-up study, 3 patients with initial abnormal MDP scan but normal MIBG scan, developed skeletal metastases detectable on MIBG scan, whereas 3 of the 46 patients who had normal MDP and MIBG scan at presentation; developed skeletal metastases detectable on MDP scan. MIBG scan was concordant in 2 of them but was normal in the third patient. Conclusion: I-131-MIBG underestimates skeletal disease burden in neuroblastoma. Therefore, Tc99m-MDP bone scan should remain a part of routine assessment of patients with neuroblastoma

Imaging using Tc99m-tetrofosmin for the detection of the recurrence of brain tumour: A comparative study with Tc99m-glucoheptonate

BACKGROUND: In the past "blood-brain barrier" agents such as Tc99m-glucoheptonate were routinely used for the diagnosis of brain tumours. Of late, agents used for studying myocardial perfusion namely, Tc99m-tetrofosmin, Thallium-201, and Tc99m-sestamibi have replaced the "blood-brain barrier agents" when imaging is undertaken for the detection of the recurrence of brain tumours. However, the incremental diagnostic information provided by Tc99m-tetrofosmin when compared with a blood brain barrier agent in the diagnosis of recurrent brain tumour has not been evaluated till date. AIMS: The study was carried out to substantiate whether Tc99m-tetrofosmin provides any incremental diagnostic information not provided by the blood brain barrier agent Tc99m-glucoheptonate. MATERIAL AND METHODS: Brain SPECT scans were performed using Tc99m-tetrofosmin and Tc99m-glucoheptonate in 126 patients of recurrent brain tumour. Bio-distribution and uptake properties of both the tracers were analysed by measuring relative uptake of both the tracers in tumour compared to background (T/B ratio), nasopharynx (T/N ratio) and scalp (T/S ratio). STATISTICAL ANALYSIS: Descriptive statistics were calculated for each variable. Pearson's correlation coefficient was applied to see agreement of the continuous variables. Paired t test was used to evaluate the difference between two means. RESULTS: Uptake properties of both the tracers were analysed in 105 patients in whom both Tc99m-tetrofosmin and Tc99m-glucoheptonate showed concentration. The remaining 21 patients in whom the tumour mass did not show Tc99m-tetrofosmin concentration were excluded from the study. Mean T/B ratio, T/N ratio and T/S ratio was 5.83 \ub1 2.09 and 5.99 \ub1 2.26, 0.53 \ub1 0.21 and 0.55 \ub1 0.22 and 1.11 \ub1 0.60 and 1.26 \ub1 0.52 for Tc99m-tetrofosmin and Tc99m-glucoheptonate respectively. No statistically significant difference between T/B ratio and T/N ratio of Tc99m-tetrofosmin and Tc99m-glucoheptonate was found; p values were 0.25 and 0.83 respectively. However there was significant difference (P=0.006) between the T/S ratio of Tc99m-tetrofosmin and that of Tc99m-glucoheptonate. CONCLUSION: Tc99m-tetrofosmin does not provide any incremental diagnostic information not provided by the blood brain barrier agent Tc99m-glucoheptonate

The epidemiology of melioidosis and its association with diabetes mellitus : a systematic review and meta-analysis

Melioidosis is an under-recognized fatal disease in humans, caused by the Gram-negative bacterium Burkholderia pseudomallei. Globally, more than 35,000 human melioidosis cases have been reported since 1911. Soil acts as the natural reservoir of B. pseudomallei. Humans may become infected by this pathogen through direct contact with contaminated soil and/or water. Melioidosis commonly occurs in patients with diabetes mellitus, who increase the occurrence of melioidosis in a population. We carried out a systematic review and meta-analysis to investigate to what extent diabetes mellitus affects the patient in getting melioidosis. We selected 39 articles for meta-analysis. This extensive review also provided the latest updates on the global distribution, clinical manifestation, preexisting underlying diseases, and risk factors of melioidosis. Diabetes mellitus was identified as the predominant predisposing factor for melioidosis in humans. The overall proportion of melioidosis cases having diabetes was 45.68% (95% CI: 44.8–46.57, p < 0.001). Patients with diabetes mellitus were three times more likely to develop melioidosis than patients with no diabetes (RR 3.40, 95% CI: 2.92–3.87, p < 0.001). The other potential risk factors included old age, exposure to soil and water, preexisting underlying diseases (chronic kidney disease, lung disease, heart disease, and thalassemia), and agricultural activities. Evidence-based clinical practice guidelines for melioidosis in patients with diabetes mellitus may be developed and shared with healthcare professionals of melioidosis endemic countries to reduce morbidity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Accumulation of Tc99m-DMSA-3 in the spleen in a case of multiple myeloma with associated amyloidosis

We describe a case of a 58-year-old male with longstanding hypertension and Type 2 diabetes mellitus who developed sudden onset renal impairment. The first clue to the possible presence of amyloidosis in this case was provided by the radionuclide renal cortical scan performed with trivalent dimercapto succinic acid (Tc99m-DMSA-3), which revealed intense tracer uptake in the spleen suggesting amyloid deposit. Further workup to ascertain the cause of amyloidosis led to the diagnosis of multiple myeloma. We conclude that in cases of extra-renal or splenic accumulation of Tc99m-DMSA-3, a diagnosis of amyloidosis should be considered, in an appropriate clinical setting

Case Report - Accumulation of Tc99m-DMSA-3 in the spleen in a case of multiple myeloma with associated amyloidosis

We describe a case of a 58-year-old male with longstanding hypertension and Type 2 diabetes mellitus who developed sudden onset renal impairment. The first clue to the possible presence of amyloidosis in this case was provided by the radionuclide renal cortical scan performed with trivalent dimercapto succinic acid (Tc99m-DMSA-3), which revealed intense tracer uptake in the spleen suggesting amyloid deposit. Further workup to ascertain the cause of amyloidosis led to the diagnosis of multiple myeloma. We conclude that in cases of extra-renal or splenic accumulation of Tc99m-DMSA-3, a diagnosis of amyloidosis should be considered, in an appropriate clinical setting

Imaging in extrapulmonary tuberculosis

Tuberculosis (TB) remains a major global public health problem, with 1.5 million deaths annually worldwide. One in five cases of TB present as extrapulmonary TB (EPTB), posing major diagnostic and management challenges. Mycobacterium tuberculosis adapts to a quiescent physiological state and is notable for its complex interaction with the host, producing poorly understood disease states ranging from latent infection to active clinical disease. New tools in the diagnostic armamentarium are urgently required for the rapid diagnosis of TB and monitoring of TB treatments, and to gain new insights into pathogenesis. The typical and atypical imaging features of EPTB are reviewed herein, and the roles of several imaging modalities for the diagnosis and management of EPTB are discussed