ANALYSIS OF THE EFFICIENCY OF A THERAPEUTIC PROGRAM USING 10.2-MEV FAST NEUTRONS. OPTIMIZATION AND PROSPECTS OF THE DEVELOPMENT OF A PROCEDURE FOR COMBINED PHOTON-NEUTRON THERAPY. THE EXPERIENCE OF THE URAL CENTER FOR NEUTRON THERAPY

The Ural Center for Neutron Therapy performs combined photon-neutron therapy for cancer patients, by applying an ELLIT-80 gamma unit and a NG-12I neutron generator. After modernization of the NG-12I generator, there was a need for redetermination of the relative biological efficiency (RBE) to optimize radiotherapy for the patients. An exotest was used to experimentally estimate RBE according to the survival criteria for stem hematopoietic cells in CBA mice after modernization of the equipment generated by the NG-12I unit with respect to the gamma radiation generated by the ELLIT-80 unit. The investigation established that the RBE factor of NG-12I unit-induced radiation determined as the ratio of equally effective doses (our study used D0) was 1.53 for an acute radiation regimen. During fractional radiation, the RBE factor of neutron radiation was 3.05. That is to say, the total neutron radiation dose replacing 20 % gamma radiation (13 Gy) in the used photon-neutron therapy regimen is 4.26 Gy. The experimental findings have led us to conclude that the previously described neuron therapy regimen may be optimized, by increasing the contribution of neutrons to the total course of radiotherapy in a definite category of patients with radioresistant tumors of the head and neck

MICROCIRCULATORY ALTERATIONS IN PATIENTS WITH OROPHARYNGEAL CANCER AFTER RADIATION THERAPY: A POSSIBLE CORRELATION WITH MUCOSITIS?

BACKGROUND: Patients affected by several forms of malignant neoplasms receive chemotherapy (CT) or radiation therapy (RT). These treatments can cause many side effects, such as oral mucositis (OM). Mucositis is the most frequently occurring early side effect of conservative treatment of patients with malignant tumors in the head and neck, and it is registered in more than 60% of cases. It occurs due to the effect of chemotherapeutic drugs on the cells of the mucous membrane, which causes their death, and to a greater extent, due to the effect of ionizing radiation on the endothelium of the blood vessels and the basal cells of the mucous membrane the submucosa. OBJECTIVES: To assess the correlation between the indicators of hemomicrocirculation of the oral mucosa and the intensity of the clinical manifestations of oral mucositis. MATERIALS AND METHODS: This study included 48 patients who had a morphologically confirmed diagnosis of squamous cell carcinoma and received radiation therapy at National Medical Research Radiological Centre (Moscow, Russia). RESULTS: It was found that, in all the subgroups, the severity index of mucositis National Cancer Institute (NCI) clearly correlated with the indicators of the flow of microcirculation through the study area at point A (r = -0.85, -0.99 and -0.77). At point A, blood perfusion in the study of hemomicrocirculation in all the subgroups 18-44 g in Ia, 45-59 g and 60-74 g in Ic was the opposite of the value of the severity of mucositis. A strong negative correlation was found between the severity of mucositis and the perfusion index at point B in subgroup Ia : (r = -0.99) along with, a moderate inverse correlation in subgroups Ib (r = -0.69) and Ic (r = -0.36). At point B, a strong inverse correlation was found in subgroups Ib and Ic (r = -0.72 and -0.65, respectively), and a moderate inverse correlation was found in subgroup Ia - NCI where r = -0.32. CONCLUSIONS: There is a negative correlation between the indicators of hemomicrocirculation of the oral mucosa and the severity of oral mucositis. It was found that the higher the lesions of the microvasculature, the lower the intensity of mucositis. These data have important prognostic value and make it possible to recommend the determination of hemomicrocirculation as a screening test

HEMOMICROCIRCULATION OF THE ORAL MUCOSA AS AN EFFICIENCY INDICATOR OF LOCAL TREATMENT AND PREVENTING COMPLICATIONS FROM RADIATION AND CHEMOTHERAPY FOR HEAD AND NECK MALIGNANCIES

BACKGROUND: Mucositis is a common and severe complication of anti-tumour therapy. The use of plant-derived drugs in patients with malignant neoplasms of the oral mucosa and maxillofacial area according to a certain group of dental risks shows good results and can be considered as one of the promising methods for the prevention and treatment of mucositis. One of the methods confirming the effectiveness of the local treatment is the determination of hemomicrocirculation in the tissues of the oral mucosa. OBJECTIVES: To determine the state of hemomicrocirculation in the tissues of oral mucosa in patients with oropharyngeal squamous cell carcinoma at different stages of anti-tumour therapy, as well as during the application of different methods for local treatment of oral mucositis. MATERIALS AND METHODS: From January 2017 to May 2018, in the Department of Radiotherapy of the National Medical Research Radiological Centre (NMRRC) of the Russian Federation, the microcirculatory parameter (MP) of hemomicrocirculation was determined in 69 patients diagnosed with oropharyngeal squamous cell carcinoma. RESULTS: In group I, hemomicrocirculation was higher at all measurement points than in group II. Clinical manifestations of oral mucositis in group I develop later than in group II and correspond to the maximum value of hemomicrocirculation in each group. CONCLUSIONS: The results confirm that the use of long-acting plant-derived drugs is more effective than traditional oral irrigation with chamomile decoction and oleotherapy for the prevention and treatment of oral mucositis: Decrease in microcirculation indicators of group I (using the drugs) is 7.4% less than one of group II (not using the drugs); p <0.04

RESULTS OF CONCOMITANT PHOTON-NEUTRON THERAPY IN THE PALLIATIVE TREATMENT OF METASTATIC BRAIN TUMORS ACCORDING TO THE DATA OF THE CHELYABINSK REGIONAL CLINICAL ONCOLOGY DISPENSARY

The authors analyzed the long-term results of standard radiotherapy (RT) in 153 patients and those of concomitant photon-neuron therapy (CPNT) in 24 patients in the combined treatment programs. The use of densely ionizing radiation in combined palliative programs for radio-resistant tumors, that include brain metastases, increased survival and improved quality of life. The survival after CPNT was 10–24 months in all the treatment programs: in the control group, that after RT and combined treatment was 4–6 and 7–11 months, respectively