Purpose: To evaluate the severity of early radiation reactions and the first results of proton therapy treatment of patients with squamous cell carcinoma of the head and neck.
   Material and methods: From January 2019 to March 2022, more than 1 400 patients received proton therapy on the proton-cyclotron complex ProteusPlus235. The search for patients was carried out in the database of patients who received proton radiation therapy for oncological diseases in the FMBA system of Russia. The study included 62 patients with confirmed squamous cell carcinoma and the unifying model was: proton therapy in the mode of five-day fractionation of SFD 2 Gr, TFD 50 Gy for locoregional lymphatic collector zones and TFD 60–70 Gy for the area of the primary tumor focus and high-risk zones. The age group is from 18 to 78 years. According to the classification of ICD10 — 35 patients were diagnosed with C00–C14 “Malignant neoplasms of the lip, oral cavity and pharynx” (56,4 %), 27 patients with C30–C32 “Malignant neoplasms of the upper respiratory organs” (43,5 %).
   Results: The assessment of long-term treatment results and the severity of radiation complications requires a systematic and uniform approach and is the subject of further research, along with the development of optimal patient models for treatment by proton pencil-beam scanning therapy.
   Conclusions: Proton beam and proton chemoradiotherapy have demonstrated decreasing trends or comparable frequency and severity of radiation reactions compared to photon therapy. In this regard, the decision to choose a treatment method should be based on an assessment of clinical efficacy, relapse-free and event-free survival, which is the subject of further scientific research.

   Relevance: Timely detection and assessment of the prevalence of pancreatic neuroendocrine tumors (p-NETs), visualization of the status of somatostatin receptors, along with morphological characteristics, fundamentally affects the tactics of treatment and long-term prognosis. In recent years, a highly specific diagnostic method ⁶⁸Ga-DOTATATE PET/CT has become available in Russia.
   Purpose: Evaluation of the effectiveness of  ⁶⁸Ga-DOTATATE PET/CT in staging and detection of p-NETs recurrence in comparison with routine visualization methods.
   Material and methods:  ⁶⁸Ga-DOTATATE PET/CT was enrolled in 55 patients diagnosed with p-NETs. Information on previous treatment was studied, as well as reports and images of CT and MRI performed no earlier than 2 months before PET/CT. In all patients, we counted foci of pathological accumulation (FPA) of  ⁶⁸Ga-DOTATATE, both the total number and their distribution in various organs and anatomical zones. The number of FPA on PET/CT was compared with the number of metastases on CT and MRI. Verification of FPA was carried out by follow up PET/CTs, as well as histological examination of the surgical material obtained after the resection of tumor foci after PET/CT.
   Results: Out of 55 patients, FPA were detected in 48 (87.3 %). Metastases were observed on CT and MRI in 36 patients (65.5 %).  ⁶⁸Ga-DOTATATE PET/CT compared with previous CT and MRI helped to identify an additional 12 people with tumor lesions. The localization of the tumor process on PET/CT completely coincided with CT and MRI in 21 patients. In five patients, the malignant process on PET/CT was detected in the same anatomical areas or lymph nodes as on CT and MRI, but additional foci were detected in these areas. In seven patients, PET/CT revealed distant lung, small pelvis and bone metastases, which were not detected earlier. Secondary isolated liver lesions were detected on CT and MRI in 10 patients. PET/CT revealed additional metastases in lymph nodes and bones in three of them. Secondary lymph node lesions on PET/CT was registered in 24 patients. On CT and MRI in 13 (diameter ≥10 mm). According to CT and MRI, metastases were detected only in the abdomen in 34 patients. PET/CT data matched in 20 (58.8 %) of them. In 14 patients (41.2 %): additional foci were found in the liver, lymph nodes, pelvis and bones. Lung metastases were detected on CT and PET/CT only in one case. Bone lesions on PET/CT were noted in eight patients, on CT and MRI in two. In four patients, primary multiple neuroendocrine tumors of other localizations (small, large intestine, kidney) were detected. Another four patients had multiple p-NETs.

   Conclusion:  ⁶⁸Ga-DOTATATE PET/CT makes a significant contribution to the assessment of the p-NETs prevalence, allows optimizing the tactics of antitumor treatment.

   Evaluation of the effectiveness of bone metastasis therapy is an urgent problem for patients with prostate cancer, mainly due to the relationship between bone metastases, survival and quality of life, which directly depends on the correct interpretation of the results of treatment response. It is known that some patients may experience a multidirectional therapeutic effect in the form of a positive response of some bone metastases and the progression of others. In addition, there are now many new therapeutics with different action profiles and often extremely expensive, so it is important to quickly recognize whether true or pseudo-disease progression is occurring, and this is more evident in patients enrolled in clinical trials with fixed protocols, often requiring radiographic assessment early after the start of treatment. Therefore, the use of additional imaging modalities in clinical practice along with PSA assessment may help improve early prediction of outcome and monitor response to therapy in patients with metastatic CRPC, optimizing the use of this costly treatment.

   Introduction: Cervical lymph node metastases from papillary thyroid cancer were classified into three categories according to ultrasound: 1) Metastases were not visible on ultrasound; 2) Metastases met initial criteria for the diagnosis; 3) Metastases met typical criteria for the diagnosis.

   Purpose: To develop initial ultrasound criteria for the diagnosis of cervical lymph node metastases from papillary thyroid cancer.
   Material and methods: We studied three groups of cervical lymph nodes in patients with papillary thyroid cancer. The first group consisted of 4307 lymph nodes that were not visible on ultrasound. However, in some of them histology revealed a metastasis. The second lymph node group consisted of 242 metastases, and the third one comprised 17 metastases causing first signs. Ultrasound imaging was performed by use of standard ultrasound machines that are widely used in clinical practice. The presence of metastases in the three groups was confirmed by histology and cytology.
   Results: According to histological data, metastases were present in 961 (22.3 %) of 4307 cervical lymph nodes of level VI located in the fatty tissue and removed for disease prevention. These lymph nodes were missed on ultrasound, so that metastases remained undetected. Typical criteria for the diagnosis of metastases were: an additional space-occupying lesion in the fatty tissue of the neck, local fat deformation, depth/width ratio over 0.5, no differentiation between the cortical and cerebral layers, predominance of the tissue nature, avascularity, calcifications. Cervical lymph nodes with extranodal extension showed some changes in the shape and outlines, metastatic spread to the adjacent fatty tissue, muscles and vessels. Initial sonographic features that helped to identify a metastasis included microcalcifications and an additional nodal space-occupying lesion occupying a part of the cortical and cerebral layers and being seen as the hyperechoic tissue or a cavity with fluid, or as a mixture of the hyperechoic tissue with fluid. The space-occupying lesion was round or ovoid in shape. There was no extranodal extension of early metastases. The space-occupying lesion was 0.5–0.7 cm in size.
   Conclusion: Ultrasound can detect metastases that cause first signs. Besides, it helps guide biopsies.

   Data of echography of 210 verified on the operation and in histological research lipomas, including 182 (86.7 %) encapsulated and 28 (13.3 %) diffuse. Four possible rims along the periphery of the formations have been identified. The morphological nature of these acoustic manifestations and the frequency of their occurrence have been determined. Elastography did not improve its differentiation by showing the boundaries of formations more clearly.

   Purpose: To evaluate the effect of previously performed radiation therapy on the successful use of a submental flap in oral reconstruction.
   Material and methods: The study included 52 patients who underwent reconstruction of oral cavity defects using a submental flap between February 2015 and January 2021. Radiation therapy was performed in 13 patients in the preoperative period at different time periods and in different doses.
   Results: From February 2015 to August 2021, to 52 patients submental flap was used to reconstruct oral cavity defects after surgical treatment of oral mucosal cancer. 13 patients received radiation therapy before surgical treatment compared to 39 who did not. In eleven cases, partial flap necrosis occurred, of which 3 underwent radiation therapy to two in a radical dose before surgical treatment. In two cases, there was a discrepancy of sutures in the oral cavity, one in each group, which did not require surgical intervention and were closed with conservative treatment. Two patients who underwent radiation therapy developed a fistula communicating with the oral cavity and neck healed spontaneously with conservative management. Marginal mandibular nerve palsy developed in three patients, one in the group with radiation therapy, the rest without a history of radiation therapy.
   Conclusions: Total flap necrosis was not observed in any group. Thus, preoperative radiation therapy is not a contraindication to the use of a submental flap to reconstruct oral cavity defects with relatively acceptable complications. The submental flap is easy to harvest, reliable, universal flap to reconstruct oral cavity defects.

   Complete liver and bile ducts resection with negative margins (R0) in the only possible radical treatment of Klatskin tumor. Even after R0 resection, the recurrence rate is as high as 50–76 %. Neoadjuvant endobiliary photodynamic therapy (PDT) may potentially improve their results and long­term survival. The authors present their own first experience of endobiliary PDT performing before liver and bile ducts resection (R0) in Klatskin tumor patient.

   The features of the interpretation and practical use of more than 100 radiological terms are considered. It is shown that in all three areas of medical radiology (radiation diagnostics, nuclear medicine and radiation therapy) there are a number of terms that do not meet the requirements that apply to scientific terminological systems. These terms do not meet the criteria of unambiguity, adequacy to the terminating concept, consistency, brevity and compliance with the norms of the Russian literary language, especially when directly copying the corresponding English terms. At the same time, it is important to ensure the correct and unambiguous interpretation of terms not only by professionals in the field of medical radiology, but also by specialists in related fields of knowledge. A brief glossary of radiological terms that are difficult to unambiguously understand is presented, which contains some of the most commonly used erroneous terms in this field, explanations of the relevant concepts and correct, according to the authors, terminological solutions.

   In this study, we described a clinical case of unoperable squamous carcinoma in the thoracic esophagus, demonstrating the effectiveness of induction chemotherapy followed by independent chemoradiotherapy and brachytherapy in patients with metastatic esophageal carcinoma. The patient was treated with induction chemotherapy, concurrent chemoradiation with weekly carboplatin AUC 2 and paclitaxel 50 mg/m² and brachytherapy. The most characteristic feature of this clinical case is that the use of brachytherapy in the complex treatment of patients with esophageal carcinoma allows increasing the dose in the target without increasing the risk of complications associated with the escalation of the radiation dose. Brachytherapy can achieve very high rates of local control with a reduction in morbidity, compared with external beam radiation therapy. In most patients, esophageal carcinoma is diagnosed at stages III–IV of the disease. Squamous cell esophageal carcinoma is an aggressive disease that, depending on the prevalence, requires various treatment methods, the search for the optimal one is still ongoing. The main standard of treatment in inoperable patients with squamous cell esophageal carcinoma is self — chemoradiotherapy. However, in patients with unoperable esophageal carcinoma, it is also possible to use induction chemotherapy followed by independent chemoradiotherapy and brachytherapy. The combined use of these methods of treatment in conditions of impossibility of surgical intervention is the method of choice in patients with stage III–IV of the disease. The standard dose of DLT for squamous carcinoma of the esophagus is 50.4 Gy. In the conducted studies, it was shown that the escalation of the dose to the tumor using remote radiation therapy leads to an increase in severe post-radiation injuries and an increase in the frequency of deaths. Induction chemotherapy plus concurrent chemoradiotherapy and brachytherapy to boost tumor, and improves disease control and survival.

   A case of ascites developed in disseminated neuroendocrine small bowel tumor G1 (Ki-67 2 %) patient due to the unlikeliest of the possible reasons, i.e. iatrogenic mesenteric arterioportal fistula, is presented in the paper. The patient after palliative small bowel resection was preparing for the liver transarterial chemoembolization (TACE) when the fluid accumulation was revealed in the peritoneal cavity at ultrasound and MR imaging. The probable ascites etiologies (peritoneal carcinomatosis, carcinoid right heart failure, portal hypertension due to tumor compression or vascular elastic fibrosis) were consistently ruled out. The fistulation between the superior mesenteric arterial branch and the superior mesenteric vein developed shot after small bowel surgery and maintaining portal ascites was occasionally found at superior mesentericography. The ascites vanished after fistula occlusion with the metal coils, and the patient proceeded to the planned liver TACE therapies with good effect.