Purpose: To study the impact of ⁶⁸Ga-DOTATATE PET/CT on the treatment tactics of metastatic pancreatic neuroendocrine tumors (pNETs).

Material and methods: 208 ⁶⁸Ga-DOTATATE PET/CTs enrolled in 50 patients. Each patient underwent ⁶⁸Ga-DOTATATE PET/CT two to ten times (median 4.2Դ2.2). At the time of the first study, the diagnosis of pNET was confirmed histologically and immunohistochemically in all patients. CT and MRI, as well as assessment of biochemical recurrence (serotonin and chromogranin-A levels exceeding the reference intervals) performed in all patients within one month before the next PET/CT. The results of all the listed studies in the detection of recurrent metastatic pNETs compared.

Results: At the first ⁶⁸Ga-DOTATATE PET/CT, metastases were detected in 46 patients out of 50 (92 %). At the same time, prior to the first PET/CT, CT and MRI revealed tumor foci only in 34 patients (68 %). Thus, compared with routine imaging methods, additional tumor foci detected in 12 patients (24 %). Among all 208 PET/CT examinations, 166 results were positive (79.8 %). According to the results of all CT and MRI studies, tumor foci diagnosed in 117 cases (56.3 %). Compared to CT and MRI, additional tumor foci detected in 49  studies (23.6  %). Metastases on PET/CT detected in 43 studies, despite the absence of biochemical recurrence. On PET/CT, pNETs recurrence was detected in six patients versus three on CT and MRI. Tumor progression — in 10 patients versus five on CT and MRI.

Conclusion: We revealed the influence of ⁶⁸Ga-DOTATATE PET/CT on the management of patients in the absence of other signs of disease recurrence or progression. ⁶⁸Ga-DOTATATE PET/CT in combination with CT and MRI contributes to earlier diagnosis of recurrent metastatic pNETs.

This review, using illustrative examples, shows the possibilities of using bone scintigraphy as a basic method for examining patients with osteosarcoma in accordance with the most significant international and domestic recommendations. The material is based on many years of experience and our own database of more than 1000 observations. The possibilities of other radionuclide diagnostic techniques in the diagnosis and monitoring of patients with osteosarcoma in solving various clinical problems are shown. The expediency of using three-phase osteoscitigraphy is based on the examination of 95 patients in dynamics. Radionuclide diagnostics has not lost its importance in the diagnosis of osteosarcoma and its metastases and continues to be in demand among pediatric and adult oncologists.

On the territory of Russia has increased the of thyroid cancer after Chernobyl NPP incidence at 1986, and currently accounts for up to 14,000 newly identified cases. Postoperative radioiodine (RAI) remnant ablation is the second stage of combine treatment of differentiated thyroid cancer, except for the prevalence of pT₁N₀M₀, with minimal level of TG and AT-TG, according to international guidelines. In the past 20 years a significant number of published practice guidelines for the treatment of this disease. However, the discussion is the amount of medication for administration activity (GBq) ¹³¹I, is required for successful ablation of thyroid remnants. The study analyzed 353 clinical cases after radical surgical treatment for DTC. In our study, the effectiveness of radioiodablation was compared with certain indicators of specific therapeutic activity ¹³¹I (MBq/kg), in groups of patients with different levels of TSH stimulation (less than 30 mME/ml, and more than 30 mME/ml). We evaluated the absorbed dose in the thyroid remnant in patients with residual thyroid tissue volume determined by US when administering ¹³¹I empirical therapeutic activity. The control of the WBS with ¹³¹I was carried out in 6 months. The average eղciency RAI was 85.5 %, there were no significant differences in the TSH stimulation groups of more than 30 mME/ml and 4-30 mME/ml (p > 0.05). If the thyroid remnant is not detected by US, the effective range of ¹³¹I specific therapeutic activity is 30-40 MBq/ kg against a background of TTG stimulation greater than 4 ՏME/ml and strict adherence to a 14-day low iodine diet. Direct radiometry followed by neck scintigraphy (1200 kBq ¹³¹I) and calculation of therapeutic activity is recommended when determining thyroid remnant by US to plan for TAD = 300 Gy and reduce the risk of radiation sialoadenitis. At the time of RAI, 3.9 % of patients had previously undetectable X-rays lung metastases with stimulated TG levels greater than 124 ng/mL after surgical treatment with SPECT/CT.

Relevance: Isolated bilobar multifocal hepatic lesion is consider to be the most common metastatic neuroendocrine tumor(NET) growth pattern. Underestimation of the metastatic burden in the NET patients at the initial diagnosis frequently occurs, thus leading to a high postoperative recurrence rate (more than 60 % of cases within 5 years).

Purpose: To identify the MRI-hallmarks of liver metastatic NETs and to present the most difficult diagnostic cases.

Material and methods: 103 patients with histology confirmed liver metastatic NET were enrolled in the study. All patients underwent abdominal contrast-enhanced (CE) MRI. A total of 241 lesions were assessed. Quantitative indicators of signal intensity (SI) on native and post-contrast T1-weighted images (WI) were measured in metastases. Additionally, the shape, contours, surface of metastases, SI on native images, characteristics of CE, the presence of hemoglobin degradation products and the boundary levels in the structure of metastases were qualitatively assessed.

Results: Metastatic liver disease in NET is mostly multifocal: 78 (75.7 %) patients had 5 or more lesions. Metastases were round in 53.5 % of cases, oval in 17.5 % of cases, irregular in 29 % of cases. In 61 % of cases, the contours of the lesions were clear, in 39 % — indistinct. Smooth and bumpy surface of metastases was determined in 31.5 % and 68.5 % of cases, respectively. The presence of hemoglobin degradation products in the structure of metastases was determined in 26.2 % of patients, the formation of the boundary levels — in 8.1 % of patients. Most of the lesions had a hyperintense signal on T2-WI with and without FS and a hypointense signal on native T1-WI. The proportions of actively, moderately and poorly MR contrast agent (MRCA) enhanced lesions were 30.8, 32.6 and 36.6 %, in the arterial phase and 16.3, 55.4 and 28.3 % in the venous phase, respectively. The apparent diffusion coefficient (ADC) values varied significantly. In some cases, small metastatic NET were visualized only in the arterial phase of CE and were not detected on other MRI sequences, thus requiring differentiation from other hepatic hypervascular lesions.

Conclusion. The MRI semiotics features of hepatic metastases from NETs is described. Small flesions of active accumulation of MRCA in the arterial phase in the presence of primary NET must be differentiated from metastatic lesions.

Wernicke encephalopathy (WE)is a rareneurologicaldisorderinducedby vitaminB1 deficiency(thiamine), which is associated with high risks of Korsakoff psychosis and death in case of untimely initiation ofspecific therapy. In addition to clinical and laboratory data, magnetic resonance imaging (MRI) of the brain, which has a fairly high specificity, plays an important role in detecting this pathology. However, a high degree of awareness ofWE by radiologists is necessary for correct interpretation ofMRI data.

This publication presents two own clinical observations ofpatients who underwent surgical interventions on the gastrointestinal tract, complicated by Wernicke encephalopathy, MRI and clinical manifestations, the key features ofthe etiology and pathogenesis ofthis pathological process are described.

Purpose: Analysis of modern approaches to dosimetric support of radionuclide therapy at the technological stages of dosimetric planning, hospitalization in a hospital and evaluation of treatment eծectiveness.

Material and methods: A comparative analysis of the methodological specifics of the dosimetric support of radionuclide therapy with the introduction of radiopharmaceuticals into the body and conventional radiation therapy using sealed sources of ionizing radiation was carried out.

Two methodically different approaches to dosimetric planning of the level of internal exposure from a radiopharmaceutical introduced into the patient’s body are considered.

The features of radiation monitoring are discussed both for the patient’s stay in the radionuclide therapy department and for safe discharge from the department for others, and for the solid and liquid radioactive waste being removed.

A comparative analysis of the functionality of various criteria for assessing the long-term and short-term effectiveness of radionuclide therapy for bone metastases was carried out.

Focal absorbed doses of internal exposure are considered as one of the criteria, for the determination of which a simplified method for their calculation is proposed based on quantitative data from SPECT/CT scanning of an X-ray phantom and a real patient who has been injected with a β-γ-emitting therapeutic radiopharmaceutical.

Results: On a clinical example of radionuclide therapy with ¹⁷⁷Lu-PSMA-617 in a patient with stage 4 prostate cancer, dose estimates of internal irradiation of foci with β-particles were obtained. Calculations were made for bone metastases of 7 localizations in dynamics for each of the 5 fractions of the course of radionuclide therapy. It is shown that the total focal doses for 5 fractions of internal exposure vary from 70.6 to 116.8 Gy for different foci, which corresponds to the literature data obtained by more accurate methods of dosimetry of internal exposure. The obtained dosimetric data were compared with efficacy estimates based on metabolic, hematological, hormonal and biochemical parameters, as well as on the tumor marker PSA.

Conclusion: In contrast to conventional radiation therapy, dosimetric support for planning and evaluating the effectiveness of treatment has not yet become the fundamental methodological basis of modern radionuclide therapy.

Radiation therapy of the primary tumor can be a stage of treatment of patients with initial IV stage breast cancer, being delievered out not only in purpose of decreasing symptom’s severity, but with an increase of progression-free survival.

Modern technologies of radiation therapy, including intensity-modulated radiotherapy and radiation therapy with deep inspiration under the control of breathing (Respiratory Gating), can significantly reduce dose to risk organs and ensure a homogeneous isodose distribution in the irradiated area, which is especially important in patients receiving systemic treatment, which in itself has clinically significant cardio- and pulmonotoxicity.

The presented clinical case demonstrates the possibility of dose reduction to organs at risk with usage of modern technologies of conformal radiation therapy.

In this clinical case, the main ultrasound semiotic signs of infarction and other pathological changes in the spleen are presented, with which diծerential diagnosis should be carried out in cancer patients.

A 6-year-old boy with ganglioneuroblastoma, received 4 courses of chemotherapy and underwent partial resection of the tumor. The control scintigraphy with ¹²³I-metaiodobenzylguanidine (¹²³I-mIBG) was performed, including the single photon emission computed tomography protocol combined with computed tomography (SPECT/CT), revealing the residual tumor with pathological uptake of ¹²³I-MIBG. In addition to this, there was a focal uptake of ¹²³I-mIBG in the gallbladder. In this clinical case we have demonstrated an atypical uptake of ¹²³I-mIBG in the gallbladder. 

Bloody nipple discharge is the main and in most cases the only symptom of the intraductal breast cancer. Detection of this pathology is a rather complex process involving the prescription of extra research methods. Ultrasound is mainly used in addition to such leading diagnostic methods as mammography, breast ductography. However, in the above case report, ultrasound is presented as an independent diagnostic method.