No abstract

Background. Histiocytosis is a heterogeneous group of rare diseases of unknown etiology. Langerhans cell histiocytosis (LCH) is characterized by an abnormal proliferation of histiocytes (activated dendric cells and macrophages). LCH is the most common form of histiocytosis, it is a potentially fatal diseases. Early detection of LCH plays an important role in its prognosis and outcome. However, the role of advanced methods of nuclear medicine in diagnosis of LCH is still to be researched. We have long-term experience in observing pediatric patients with LCH. Taking into the account the difficulty of diagnostic task for bone scintigraphy in identifying lytic bone destruction, we stated the following objective of the study. Objective. Our aim was to perform retrospective analysis of bone scintigraphy examinations of treatment-naive pediatric patients with LCH and calculate the diagnostic efficacy of bone scintigraphy. Methods. We retrospectively analyzed 55 examinations of treatment-naive pediatric patients (the median age was 5.9 years) with proven case of LCH (2014–2018). Results. During examination we visualized 82 lesions with pathological level of accumulation of radiopharmaceutical in 55 patients. 78 with high level of accumulation (>120%); 3 with slightly increased level of accumulation (100–120%) and 1 with lower than normal level of accumulation (<100%). The median level of accumulation of radiopharmaceutical was 276%: max. level of accumulation was 1422% (patient with subtotal involvement of femoral bone), min. — 60% (patient with lytic destruction in orbital bone). During X-Ray we found out 91 pathological focuses of bone lytic destruction. In 3 patients with polyostotic form we found extra focuses on scintigraphy, which were confirmed with following examination and X-Ray. 8 lesions were not found on scintigraphy in 8 patients. Сonclusion. Bone scintigraphy with 99mTc-MDP in treatment-naïve pediatric patients with proven case of LCH showed sensitivity — 91.0%, specificity — 50.0%, NPV — 11.1%, and PPV — 98.8%.

The temperature behaviour of the 0.955 AgNbO3--0.045 LiTaO3and AgNbO3 ceramics were studied in the range from 10 to 415 K by Raman spectroscopy. Ab initio calculations of the Raman spectra...

Introduction: Cancers that are known collectively as head and neck cancers can vary in their histological form and localization. This disease has a high social significance thus it require well-timed and delicate approach, especially in children. We can improve the accuracy of our methods by using new algorithms and technologies. We were the first to implement 99mTc-MIBI SPECT/CT imaging in evaluation of children with head and neck cancer and introduce it as a routine method in Russia. Purpose: Improve the accuracy in diagnostics of children with head and neck cancer by practical application of hybrid SPECT/CT method. To determine diagnostic value of planar scintigraphy and 99mTc-MIBI SPECT/CT in children with head and neck cancer. Material and methods: This study was performed as a prospective clinical study. Between January 2017 and December 2017, 53 patients which met the inclusion criteria were examined. The inclusion criteria were patients with histologically proven malignancy, age 1–18, weight more than 10 kg, up to date CT or MRI scans (less than two weeks passed from scanning), for initial patients a tumor findings (more than 20 mm in the largest scale). We concluded 61 whole body planar scintigraphy followed by head and neck 99mTc-MIBI SPECT/CT examinations. 10 patients were examined twice, 1patient was undergoing for this procedure for three times. Initial patients – 23, dynamic – 30. We performed scanning using a hybrid SPECT/CT after 15 minutes 99mTc-MIBI was injected. First stage was standard whole-body planar scintigraphy, second stage SPECT/CT (head and neck). Results: We evaluated diagnostic accuracy of planar scintigraphy and 99mTc-MIBI SPECT/CT. Planar scintigraphy sensitivity, specificity, NPV and PPV were 68.8, 96.6, 73.7, 95.7 %. SPECT/CT – 87.5, 96.6, 87.5, 96.6 %. The verification method was histological examination or follow-up imagining (CT or MRI) during a 12 month period. Additional imagining using hybrid SPECT/CT method allows us to increase sensitivity and NPV of isotope scanning. Most of false-negative results were obtained after planar scintigraphy, it can be related with image interpretation difficulties caused by equivocal image, especially, in patients during therapy. Six of such patients were correctly diagnosed with SPECT/CT and we revealed the presence of active tumor tissue. With CT we additionally detected destruction of skull bones in 10 patients. Conclusion: 1. Diagnostic accuracy of scintigraphy with 99mTc-MIBI is high: Sens. – 68.8 %. 2. We can increase diagnostic accuracy using hybrid methods, and so it plays an important role in final diagnosis: Sens. – 87.5 %, Spec. – 96.6 %. 3. SPECT/CT additionally detected destruction of skull bones even with negative scintigraphy results. 4. A strict clinical reasoning is needed in each individual case. 5. A further evaluation of the diagnostic capabilities of 99mTc-MIBI SPECT/CT in a larger number of patients appears justified.

Purpose: To define the diagnostic capabilities of SPECT/CT in comparison with WBS in patients with bone metastases. Material and methods: It was included 67 patients with bone metastases of breast cancer, prostate cancer and other tumors. The evaluation was included WBS and SPECT/CT. Results: All patients were divided into 2 groups: with single and multiple metastases. SPECT/CT showed higher efficiency in detecting bone metastases than WBS. The full detection of bone metastases with WBS ranged from 31 to 56 % compared to SPECT/CT for groups respectively. In some cases (for groups respectively 4 % to 9.5 % depending on the number of metastases and their localization) of WBS was not informative, recorded the absence of lesions. Conclusion: SPECT/CT can improve the diagnosis of bone metastasis.