Vol 68, No 5 (2023)
Radiation Biology
Protective Properties of Compound AICAR in vivo Exposed to Radiation
Abstract
Purpose: To study the effect of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) on the survival rate of mice and proportion of polychromatophilic erythrocytes (PCE) in the bone marrow cells with micronuclei (MN), as well as post-irradiation urinary excretion of cell-free nuclear DNA (cf-nDNA) and mitochondrial DNA (cf-mtDNA) in rats.
Material and methods: Male Balb/c mice aged 2 months and Fisher-344 male rats aged 3 months were used. To determine the survival rate of mice, X-irradiation was performed at a dose of 8 Gy, and to analysis the proportion of PCE in the bone marrow cells with MN, at a dose of 2 Gy. Rats were X-irradiated at a dose of 5 Gy. AICAR was administered to animals intraperitoneally at a dose of 400 mg/kg. The drug was administered 30 min before and 20 min after irradiation of the animals. The DNA content was measured by real-time PCR.
Results: The results of the study showed that the introduction of AICAR causes a statistically significant increase in the survival rate of irradiated animals. The greatest effect was shown in the group of mice treated with AICAR 20 min after their irradiation at a lethal dose. The introduction of AICAR before irradiation reduces the proportion of PCE with MN by 30 %, and after irradiation ‒ by 70 %, in comparison to the control. AICAR promoted enhanced urinary excretion of cf-nDNA and cf-mtDNA fragments in rats after irradiation.
Conclusion: The results show that AICAR acts as a radiomitigation effector and promotes active DNA excretion of damaged cell from animal tissues in the post-radiation period.
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Late Effects of γ, n-Irradiation of Mice: Shortening of Telomeres and Tumors Development
Abstract
Purpose: To investigate the telomere length (TL) of bone marrow and thymus cells as a marker of replicative aging late after the prolonged γ, n-irradiation of mice at low and moderate doses and analysis of the appearance of tumors by the end of the experiment − after 14 months.
Material and methods: C57Bl/6 and CBA mice were irradiated at doses of 10–500 mGy at the OR-M facility using Pu-Be radionuclide sources at a total absorbed dose rate of neutrons and gamma rays of 2.13 mGy/h, 75 % of which – 1.57 mGy/h – accounted for neutrons with an average energy of 3.5 MeV. Absolute TL in bone marrow and thymus cells was determined using real-time PCR 2 months and 1 year 2 months after irradiation, and the mean TL was calculated. Tumors found during the mice organs examination after autopsy were subjected to histological examination.
Results: It was shown that the TL in bone marrow and thymus cells of control CВA mice was 2 times higher than the TL observed in C57Bl/6 mice. Prolonged γ, n-irradiation of C57Bl/6 mice led to a dose-dependent decrease in TL in bone marrow cells 14 months after exposure, which was statistically significant at doses of 100 and 500 mGy. A decreased TL in the thymus was found only at a dose of 500 mGy. During this period, TL in bone marrow cells of CBA mice was reduced in dose-independent manner, starting from as low as 10 mGy, but no statistically significant decrease in TL was found in the thymus. The results obtained indicate the acceleration of replicative senescence of bone marrow cells in mice in the long term period after γ,n-irradiation already at low doses, and in thymus cells only at a dose of 500 mGy. Twenty-four hours after irradiation at doses of 100 and 500 mGy the number of leukocytes in mice of both lines was reduced, which was recovered in C57Bl/6 mice after a week, and in CBA mice – after two weeks. In 14 months after γ, n-irradiation, the appearance of tumors was found in mice of both studied lines: in CBA mice, lung adenocarcinoma at a dose of 50 mGy (in 1 out of 10) and uterine carcinosarcoma at a dose of 500 mGy (in 1 out of 10); in C57Bl/6 mice, keratinizing squamous cell carcinoma of the uterus at a dose of 500 mGy (2 out of 10) was seen in the absence of tumors in control mice. Histological examination of the liver of CBA mice after γ, n-irradiation at a dose of 500 mGy revealed deep dystrophic changes, the causes of which are not clear.
Conclusion: The results obtained indicate a high biological hazard of prolonged γ, n-irradiation at doses above 10 mGy, since after irradiation at this dose, an acceleration of replicative senescence of bone marrow cells in the long-term period was found, and the possibility of tumor formation increases after irradiation at a dose of 50 mGy and higher.
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Radiation Safety
Integration of ICRP OIR Models Into the iDose 2 Dosimetry System
Abstract
Introduction: The iDose 2 dosimetry system is a tool for assessing the doses of internal irradiation of workers under the current individual dosimetry control (IDC). In this system, according to a series of measurements of the activity of radionuclides in biological objects (including those not exceeding the detection limit of the measurement technique) and information on contact times and types of compounds, estimates of the committed effective dose equivalent (CEDE) of internal irradiation, as well as their uncertainties, are made based on the Bayesian approach. It is possible to integrate practically any biokinetic models of the behavior of radionuclides in the human body, presented in the form of a system of ordinary differential equations (ODEs) with constant transition coefficients between compartments, into the iDose 2 dosimetry system without changing the source code.
Purpose: Integration of new combined biokinetic models for the list of radionuclides: H-3, Sr-90, Cs-137, Pu-238, Pu-239 and Am-241 from Publications 100, 130, 134, 137 and 141 of the ICRP (conventionally called the series Occupational Intakes of Radionuclides (OIR)), for ingestion and inhalation routes of intake with AMAD = 1 and 5 microns.
Material and methods: For each variant of the biokinetic model, the functions of retention/removal of radionuclides were found through the eigenvectors and eigenvalues of the matrix describing the ODE system.
Results: A total of 65 new biokinetic models and 180 functions of radionuclide retention/removal in the form of a sum of exponents were integrated and quality control was carried out.
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Radiation Situation Around Commissioning Mine No. 6 of PjSC 'Priargunskiy Mining and Chemical Production Association'
Abstract
Purpose: Study of the radioecological situation around mine No. 6 of PJSC ‘Priargunsky Industrial Mining and Chemical Association’ named after E.P. Slavskiy" before commissioning.
Material and Methods: During the radiation survey, to measure the ambient dose equivalent rate, the pedestrian gamma survey method was used using the portable spectrometric complex MKS-01A ‘Multirad-M’ (Russia) and the dosimeter-radiometer MKS-AT6101s (Belarus). To study the specific activity of radionuclides in the soil, samples were taken in accordance with GOST 17.4.3.01-2017. The activity of gamma-emitting radionuclides was measured on a stationary gamma spectrometer manufactured by Canberra (USA). The activity of 210Po and 210Pb was measured on the radiometric system UMF-2000 (Russia) after their radiochemical extraction from samples. Dose assessment of exposure to biological objects was made using dose coefficients established in ICRP Publication 136, considering recommendations R52.18.820-2015.
Results: The results of the study showed that the ambient dose equivalent rate of gamma radiation varied in a wide range from 0.1 to 4.9 µSv/h. The average value in the background areas is 0.14±0.02 µSv/h. The specific activity of natural radionuclides outside the rock dumps, except for 40K, in some areas exceeds the background values up to 10 times. The ecological risk for the considered terrestrial biological objects (grass, shrub, soil worm and mouse-like rodents) does not exceed 10‒2.
Conclusion: There are areas on the territory with traces of anthropogenic activity, which led to man-made radiation contamination. The highest levels of ambient dose equivalent of gamma radiation occur near rock dumps. The rest of the territory has local areas with radioactive contamination. Doses of exposure to biological objects don’t have a significant effect on the incidence, reproduction, and life expectancy of terrestrial biological objects.
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When the Factor of Crystallized Intelligence Can Be a Professionally "Undesirable" Personal Quality of Operators
Abstract
Purpose: To discuss the case of oppositely directed influences of the indicators of crystallized and fluid intelligence in the decisive rule designed to predict the professional success of the nuclear power plants (NPPs) operators.
Material and methods: This paper analyzes the results of psychodiagnostic examinations of operators of main control rooms (MCR) of NPPs that functioned under normal conditions. All individuals were administered the J. Raven’s “Progressive matrices”, the Russian language adaptation of the Minnesota Multiphasic Personality Inventory (MMPI) and the Sixteen Personality Factor Questionnaire (16PF, form A). A cross-expert review using the ranking method revealed two groups of operators with relatively higher and lower levels of professional success. The method of canonical correlation analysis has been used to obtain the best linear discriminator for predicting the professional success of MCR operators based on indicators of psychodiagnostic tests.
Results: Based on the results of the expert assessment, two groups of operators with the highest and lowest professional success were identified. Decisive rule were obtained that make it possible to predict the professional success of operators based on a system of signs (values of the psychodiagnostic tests scales multiplied by coefficients) after the data processing using canonical correlation analysis. Unexpected result was that the high values of 16PF factor «B» turned out to be «undesirable» for the prediction of professional success, that is, these values increased the probability of assigning the operator to the group of the lowest successful specialists.
Conclusion: Factor «B» of 16PF was considered as a tool for assessing predominantly crystallized intelligence, and the Raven’s test – for the fluid one. At the same time, there are no methods that allow measuring these indicators in their purest form. Taking this fact into account, the author believes that the true role of factor B in the decisive rule did not reflect the undesirability of advanced crystallized intelligence among MCR operators. It is most likely that its opposition to the «desirable» indicator (the number of correctly solved tasks of the Raven’s test) made it possible to single out the role of fluid intelligence (or some of its lower-level aspects) as a professionally important quality for the particular operator activity.
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To the Question of the Interpretation of the Terms "Dose Limit" and "Radiation Accident" in the Development of New Norms of Radiation Safety
Abstract
Purpose: To analyze the existing in NRB-99/2009 and proposed in the journal “Medical Radiology and Radiation Safety” interpretations of the terms “dose limit” and “radiation accident” when developing a new version of this regulatory document.
Material and methods: The features of the interpretation of these terms are considered both in NRB-99/2009 and in a number of domestic and international reference books and glossaries on radiation safety, including proposals published in No. 4 of the journal “Medical Radiology and Radiation Safety” for 2023.
Results: The interpretation of the numerical values of the dose limits proposed in the indicated journal seems to be poorly substantiated, while their traditional interpretation remains more preferable. The addition of the concept of a radiation accident with the term “emergency” with its own explanation by the authors of the article contradicts the recommendations of the IAEA. The necessity of taking into account the specifics of radiation accidents in medicine when interpreting the term “radiation accident” is shown.
Conclusions: 1. There is no need to revise the traditional interpretation of the numerical values of dose limits. 2. It is expedient to replace the wording of the concept of a radiation accident existing in NRB-99/2009 with the wording of the same concept from the IAEA glossary on radiation safety. 3. Taking into account the need for a correct interpretation of the concept of a radiation accident in medicine, the terms “radiation incident”, “unintentional (accidental) medical exposure” and “radiation accident” with their corresponding interpretations should be added to the new version of the NRB.
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Radiation Medicine
State of Bone Marrow Hematopoiesis in Chronic Radiation Disease Patients, Irradiated with Different Dose Rates
Abstract
Purpose: to study the features of the state of the bone marrow according to cytological and histological studies at different periods of the course of CRD, caused by exposure to different dose rates, which developed as a result of professional prolonged exposure in a cohort of former employees of a radiation hazardous enterprise who underwent inpatient examination at the clinic of the A.I. Burnazyan Federal Medical and Biomedical Center in the period up to 1995.
Material and methods: the study of the results of cytological and histological studies of the bone marrow was carried out in former workers of the Mayak Production Association who were exposed to long-term industrial exposure with a dose rate of 0.008−0.07 Gy / day (15 people), 0.003−0.007 Gy / day (12 people) and less than 0.001 Gy/day (25 people), during periods of formation, outcomes, immediate and long-term consequences of CRS. At the stage of studying the results of histological examination of the bone marrow, 54 more patients with CRS were added to the third group, irradiated with a dose rate of less than 0.001 Gy / day.
Statistical processing of the material was carried out using the IBM SPSS Statistics software package.23 using the Kruskal‒Wallis test and the Mann‒Whitney U-test for independent samples. The results obtained were considered statistically significant at p < 0.05.
Results: At a dose rate of 0.008−0.07 Gy / day during the formation period, the myelogram revealed narrowing of the granulocyte and expansion of the red germs, acceleration of maturation of granulocytes with a normal erythrocyte maturation index and leuko-erythroblast ratio. In peripheral blood – agranulocytosis. In the period of outcomes and immediate consequences − narrowing of the granulocytic, expansion of erythrocyte germs, acceleration of maturation of neutrophils with other myelogram parameters within normal limits. In the blood − agranulocytosis, anemic syndrome. In the long term, in the case of restoration of hematopoietic function, narrowing of the granulocytic germ with other myelogram parameters within the reference values. However, with a similar course of CRS in 60 % of patients in periods of outcomes and long-term consequences, the development of myelodysplastic syndrome with transformation into acute leukemia or aplastic anemia is possible.
At an irradiation dose rate of 0.003−0.007 Gy / day in the period of CRD formation, the myelogram revealed an expansion of the granulocytic germ, with other indicators within the normal range. In the period of outcomes and immediate consequences, an acceleration of maturation of granulocytes and an increase in the leuko-erythroblastic ratio were found. In the long term, a narrowing of the granulocytic and expansion of the erythrocyte sprouts, a slight acceleration of the maturation of granulocytes were found. Hystological examination: polymorphocellular bone marrow – in 11 out of 25 patients, hypoplasia – in 9 out of 25, signs of hyperplasia – in 5 out of 25. In the long term, 2 patients from this group developed oncohematological diseases.
At an irradiation power of less than 0.001 Gy / day, during all periods of CRD, normal values of granulocytic and erythrocyte sprouts were noted in the myelograms of patients. In the period of CRD formation, the normal size of the granulocytic germ was achieved due to the accelerated maturation of neutrophils. The leuko-erythroblastic ratio in the period of long-term consequences was significantly higher than the norm (5.29 and 4.5, respectively). Hystological examination: 32 out of 64 patients had polymorphocellular bone marrow, 22 out of 64 had hypoplastic bone marrow, 7 out of 64 had bone marrow hyperplasia.
Conclusion: regular changes in hematopoietic tissue and peripheral blood in CRD can serve as diagnostic criteria, based on which it is possible to assume the dose rate of radiation to which the patient was exposed, and also on their basis, it is possible to predict the outcome and long-term consequences of CRD that developed as a result of this exposure.
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Comparative Characteristics of EEG Frequency Bands and Cerebral Energy Exchange at a Low Level of Psychophysiological Adaptation in Employees of Nuclear Hazardous Enterprises and Productions
Abstract
Purpose: Comparative assessment of the functional state and energy processes of the brain in workers of nuclear hazardous enterprises and industries with high and low levels of psychophysiological adaptation (PPA). The parameters of the spectral power of the EEG frequency ranges and cerebral energy exchange at low and high levels of PPA, low and high functional activity (FA) of conditionally isolated structural and functional formations (SFF) characterizing: mental level of functioning − SFF-1, psychophysiological level − SFF-2, physiological − SFF-3 were compared.
Material and methods: 311 archived EEG – 159 individuals with a low level of PPA (50.8±4.6; 13 women); 152 EEG individuals with a high level of PPA (48.8±1.5; 12 women). The power of the frequency ranges of the EEG was evaluated by computer analysis using the fast Fourier transform algorithm; cerebral energy exchange using the value of the hemispheric differences in the power of biopotentials of EEG homologous leads.
Results: At a low level of PPA, higher activity of cortical structures and higher cerebral energy exchange were revealed. In the SFF the changes manifested themselves in different ways. Increased activity of cortical structures was noted in SFF-1 and SFF-3 (in all areas of the cortex, including temporal, associated with the limbic-reticular complex). In SFF-2, the activity of cortical structures weakened both in the anterior and posterior parts of the cortex, the activity of the temporal zones did not change. Increased cerebral energy exchange was noted in SFF-1 and SFF-2. It was detected in the anterior parts of the cortex, and was not detected in the posterior. In SFF-3, the cerebral energy exchange did not change – neither in the anterior nor posterior parts of the cortex.
Conclusion: Various SFF of the brain take part in ensuring brain activity at a low level of PPA, which is reflected in the characteristics of EEG frequency spectra and indicators of cerebral energy exchange of the brain regions concerned. The processes associated with the participation of structural and functional education reflecting the mental level of functioning (SFF-1) are characterized at a low level of PPA by increased activity of the anterior cortex, which is accompanied by increased cerebral energy exchange. The deepening of research in this direction may contribute to the identification of additional compensatory mechanisms of the brain aimed at ensuring the functional activity required for the exercise of professional activity by persons with a low level of PPA.
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Radiation Epidemiology
Individualized Approach to the Formation of High Cancer Risk Groups Based on the Assessment of Immunological Indicators in Chronically Exposed People
Abstract
Introduction
1. Main risk factors of radiation-induced carcinogenesis
2. Stages of an individualized approach to the formation of high-risk groups for cancer
3. Comprehensive medical examination of a patient
4. Determination of risk of radiation-induced carcinogenesis
5. Measures for prevention and (or) early diagnosis of radiation-induced malignant neoplasms
6. Monitoring of immunity indicators in persons at high risk of radiation-induced carcinogenesis
Conclusion
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Risk of Thyroid Diseases Associated with Iodine Deficiency of Liquidators of the Consequences of the Accident at the Chernobyl NPP - Employees of Nuclear Industry Enterprises
Abstract
Purpose: Assessment of thyroid disease risk associated with iodine deficiency, liquidators of the Chernobyl accident consequences, employees of nuclear industry enterprises depending on the doses of different types of exposure.
Material and methods: The dose-risk assessment study included 12663 men, 1327 of whom had occupational exposure data. A Poisson’s process with intensity parameter was chosen as a statistical model of morbidity risk. The statistical package of epidemiological data analysis EPICURE was used for the estimation of excess relative risk (ERR) of thyroid diseases related to iodine deficiency. There was conducted a cohort epidemiological study of a group of liquidators who worked in the 30-km zone in 1986‒1990 over a period of more than thirty years depending on the dose received both during liquidation of the Chernobyl accident consequences and during professional work with radioactive substances (RS) and ionizing radiation sources (IRS).
Results: As a result of the study direct estimates of radiogenic risk of thyroid diseases associated with iodine deficiency in the liquidators of the Chernobyl accident consequences were obtained for the first time using the data on doses of Chernobyl and the sum of these doses with the doses of occupational exposure. It is shown that the risk of disease per unit dose (ERR/Zv) for dose loads received both at liquidation of Chernobyl accident consequences and for total doses give different results.
Conclusion: Assessment of the risk of thyroid diseases associated with iodine deficiency, liquidators of the Chernobyl NPP accident consequences and workers of nuclear industry enterprises, serviced by FMBA health care institutions of Russia using the doses of different types of exposure gives different results.
Correct results of assessing the risk of radiation-related diseases can only be given by the register using the total radiation dose (occupational, accidental, medical, natural), as required by the directive documents.
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Radiation Therapy
Ten-Year Results of Complex Treatment of Patients with Primary Local Advanced Breast Cancer
Abstract
Purpose: To present ten-year results of complex treatment of patients with primary locally advanced breast cancer, depending on the type of ionizing radiation used and chemotherapy regimens.
Material and methods: The study included 250 patients with stage T2‒4N0‒3M0 breast cancer, aged 34–69 years (mean age 48.1±5.6 years), who underwent complex treatment (courses of NChT and AChT, hormonal and targeted therapy (according to indications), radical mastectomy and radiation therapy with various types of ionizing radiation) at the Research Institute of Oncology from 2007 to 2020. The mean follow-up period was 10±2.7 years. Main group (n=110) ‒ neutron therapy, comparison group I (n=80) ‒ photon therapy, comparison group II (n=60) ‒ electron therapy.
Results: Ten-year relapse-free survival of patients with locally advanced breast cancer
(PL BC) after adjuvant neutron therapy on the area of the anterior chest wall was 92.5±3.5 %, after photon therapy ‒ 70.9±5.6 %, after electron therapy ‒ 73.6±7.1 %. There were statistically significant differences between the main group and comparison groups (p<0.05). Overall survival over a ten-year follow-up period in the main group was 87.5±3.8%, in comparison group I ‒ 73.6±8.6 %, in comparison group II ‒ 38.8±10.0 %. Between neutron and electron therapy – p<0.05. In the group with neutron therapy and chemotherapy according to doxorubicin + taxane regimens, ten-year metastatic-free and overall survival was 72.8±10.0 % and 96.7±3.3 %, respectively, compared with neutron therapy and chemotherapy according to FAC/CAF regimens ‒ 44.0±14.7 % and 83.7±6.7 %, respectively (p<0.05). Neutron therapy was well tolerated by all breast cancer patients. Radiation reactions of the skin predominantly I‒II degree. Radiation pneumonitis after neutron therapy ‒ in 6 (5.4 %) out of 110 patients, after photon therapy ‒ in 17 (21.25 %) out of 80 patients with PL BC (p=0.023).
Conclusion: Thus, the use of adjuvant neutron therapy in patients with breast cancer T2‒4N0‒3M0 is a safe method and has significantly better results in ten-year relapse-free survival, which makes it possible to increase the effectiveness of complex treatment. In combination with doxorubicin + taxane chemotherapy regimens, neutron therapy increases the 10-year metastatic-free and overall survival rates.
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Thermoradiochemotherapy in the Combined Treatment of Rectal Cancer
Abstract
Currently, the treatment of rectal cancer requires a multidisciplinary approach. So the combined method of treatment, including chemoradiotherapy and the surgical stage, has proven itself reliably. However, the desired results that significantly increase the rates of relapse-free and metastatic survival have not yet been achieved. The use of radio modifiers makes it possible to enhance radiation exposure without increasing the total focal dose. One of the universal radio modifiers is local hyperthermia.
Purpose: To develop a method of thermoradiochemotherapy in the combined treatment of distal rectal cancer and evaluate its effectiveness.
Material and methods: This work is based on the analysis of the results of treatment of 141 patients with morphologically confirmed locally advanced distal rectal cancer. In accordance with the objectives of the study, all patients were divided into 2 groups. In the combined treatment of 75 patients, the first stage was performed chemoradiotherapy (CLT) in combination with local hyperthermia (LH). Local hyperthermia was not used in the treatment of 66 patients.
Results: Long-term results of complex treatment of patients with an independent course of chemoradiotherapy/thermochemoradiotherapy (dynamic observation group) and after surgical treatment are presented. One – year relapse-free survival in the group with an independent course of TRHT was 96.7 %, in the CLT group – 79.3 % (p=0.024). There was a significant increase in three–year relapse-free survival – 93.3 % versus 76.7 % in the control (p=0.041). Among patients who underwent surgical treatment at the second stage, the study of one-year relapse-free survival did not reveal statistical significance. Three – year relapse-free survival in patients with TRHT compared with the CLT group was 96.2 % versus 86.0 % (p=0.038). The effectiveness of thermoradiochemotherapy in patients of this category was evaluated. The tolerability of treatment in all patients is satisfactory. Among all radiation reactions, the most frequently observed phenomena of radiation epidermitis I–II art. in the projection of irradiation fields (Table 1). Acute radiation reactions were reversible and did not have a negative effect on the subsequent stages of treatment. Treatment for all patients (n=141) was implemented in full.
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Nuclear Medicine
Variants of Sentinel Lymph Node Research Protocols in Breast Cancer
Abstract
Purpose: To study the advantages of the technique of administering a radiopharmaceutical according to the “two-day protocol” for determining the sentinel lymph node in breast cancer. Compare the methods of introducing radiopharmaccutical according to the “two-day protocol” and the “one-day protocol”. To identify the advantages of using the “two-day protocol” method over the “one-day protocol” method.
Material and methods: In order to improve the diagnosis and treatment of breast cancer by means of a sentinel lymph node biopsy (SLNB) using the technique of introducing a radiopharmaceutical a day before surgical treatment, we analyzed 76 patients with various molecular biological types and stage of breast cancer disease who underwent examination and treatment in the conditions of the P.A. Herzen Moscow State Medical Institute. This cohort of patients was divided into 2 comparable groups: 1 group of patients who underwent SLNB according to a two-day protocol (n=38), the 2nd group of patients who underwent SLNB according to a one-day protocol (n=38). The ambient equivalent dose rate of photon radiation was measured using the MKS-08P dosimeter on the day of RP administration and on the day of surgery.
Results: On average, the dose rate of photon radiation 0.5 m from the injection point on the day of radiopharmaccutical administration (according to the “one-day protocol”) and on the day of surgery (according to the “two-day protocol”) was 46.9±23.1(11.0‒85.4) and 2.2±1.1(1.0‒6.4) μSv/h, respectively. The average value of thedose rate directly in the colloid injection zone two hours after administration is equal to 185.1±25.7 (138.9‒258.0) μSv/h, a day later ‒ 9.8±3.8 (6.5‒27) μSv/h. In the first group, when using the “two-day protocol”, when scanning the SPECT/CT in 34/38 (89.5 %) patients revealed 83 lymph nodes, in the second in 30/38 (78.9 %) patients – 72; the total number of removed lymph nodes ‒ 147 and 156, respectively. With an urgent cytological examination, adenogenic metastases were detected in 8 cases in the first group, in 11 cases in the second. In 11/38 (29.0 %) patients, according to the “two-day protocol”, the number of detected and removed lymph nodes is equal, “according to the one-day protocol” ‒ in 5/38 (13.2 %). The scan did not reveal any SLN in the first group – 5/38 (13.2 %), in the second – 7/38 (18.4 %).
Conclusions: The advantage of using the “two-day protocol” was revealed, consisting in an 18-fold decrease in background radiation. And also, a faster and more accurate determination of the sentinel lymph node in the surgical field using a gamma detector, associated with a minimum number of cases of scattered radiation in the area of regional lymph outflow, in contrast to the weak accumulation of “sentinel” lymph nodes and strong background radiation outside the nodes when a radioisotope is injected on the day of surgery. The “two-day protocol” greatly facilitates the work of the oncologist surgeon, contributes to a more accurate determination and biopsy of the sentinel lymph node, reduces the radiation load on medical staff during surgery.
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Radionuclide Diagnosis of Sentinel Lymph Nodes in Breast cancer with a Radiopharmaceutical Based on Technetium-99m Labeled Gamma Aluminum Oxide
Abstract
Аim: To analyze the results of radionuclide diagnostics of sentinel lymph nodes (SLN) in patients with breast cancer (BC) with the radiotracer Sentiscan, 99mTc (manufacturer “MedicorPharma-Ural”) using the multimodal SPECT/CT at the stage of visualization.
Material and methods: The study was retrospective, it included 48 patients with BC with clinical stage T2-3N0M0, who underwent radionuclide diagnostics of SLN and SPECT/CT was performed at the imaging stage. The images were evaluated visually, the intensity of the radiotracer accumulation in the lymph nodes (LN) was analyzed, SUVmax was used as a quantitative parameter. Intraoperative detection of SLN with subsequent histological examination was also carried out with the calculation of the level of the radiotracer accumulation.
Results: On tomoscintigrams, LNs were visualized in 43 patients out of 48, intraoperatively ‒ in 46 cases, in 2 patients, accumulation of the radiotracer in the LN projection was noted neither according to SPECT/CT, nor intraoperatively. When analyzing the intensity of the radiotracer accumulation according to SPECT/CT data, a rather large scatter of SUVmax‒35 [10‒104]. Sentinel were considered LNs with the level of the radiotracer accumulation in them of at least 10 % of the most intense node. According to SPECT/CT data, 165 lymph nodes were identified, the average number of lymph nodes detected in one patient was 2 [1‒3], the maximum number was 6 lymph nodes. In all patients, the lymph nodes were determined in the projection of the 1st level, in 25 cases ‒ in the projection of other zones of regional lymphatic outflow. The total number of lymph nodes removed during surgery was n=247, on average 3 [2‒5] lymph nodes were removed in one patient, with a maximum of 8 nodes.
Conclusion: The sensitivity of radionuclide diagnostics of SLN with Sentiscan, 99mTc was 89.6 % according to SPECT/CT and 95.8 % according to the results of intraoperative detection. The use of multimodal imaging provides information on the exact anatomical localization of the lymph nodes. In the absence of scintigraphic visualization of the radiotracer redistribution in the lymphatic collector, intraoperative detection does not lose its relevance.
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SPECT/CT with 99mTc-Technetryl in Staging, Planning of External Radiotherapy and Follow-up in Lung Cancer: a Clinical Case and Case - Addressed Review of Literature
Abstract
The case of a patient with newly diagnosed peripheral cancer of the right lung, involving the pleura, in whom the local extent of the process initially detected by X-ray CT was significantly extended from the data of the SPECT with 99mTc-technetryl. In particular, with SPECT/CT before the start of radiation therapy (RT), involved lymph nodes were detected both in the lower edge of the root of the right lung, and in paraaortic and paratracheal location. The SPECT/CT with 99mTc-technetryl was carried out with dual-detector gamma-camera GE Discovery NM/CT 670 DR (GE Medical) in a quantitative mode, with calibration and calculation of indexes of standardized uptake values (SUV) and % uptake of the administered activity by the primary tumor and metastatically involved lymph nodes. The values of the volume of tumor tissue were, respectively, for the tumor and the largest proximal metastatically involved lymph node 154.2 cm3 and 12.9 cm3, % of the activity absorbed by the tumor tissue − 0.498 and 0.030 %, and SVP ‒ 2.19 and 2.5.With subsequent external radiation therapy (in total 40 Gy, 2 Gy 5−6 times a week) the irradiation fields were planned in such a way that all affected lymph nodes were within their borders. A control SPECT/CT study carried out immediately after the RT showed a decrease in the volume of tumor tissue in the primary node down to 58 cm3, % of the activity absorbed by the tumor tissue to 0.090 %, and SVP ‒ to 1.15. Reliable imaging of lymph nodes after LT was not observed. After 6.5 months, no evidencies for relapse or continued tumor growth were detected with a control X-ray CT performed on an outpatient visit with contrast enhancement.
Thus, SPECT/CT with 99mTc-technetryl in lung cancer is a vital method for clarifying the diagnosis and assessment of the extent of the tumor process, as well as monitoring the patient. A broad inter-center assessment of abilities of the SPECT/CT with 99mTc-technetryl in lung cancer is advisable, especially when planning RT.
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Anniversary
Congratulations on the Anniversary!
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