The current state and prospects for the development of nuclear medicine in pediatrics was analyzed on the basis of literature data and own experience. The main directions of radionuclide diagnostics and radionuclide therapy in children were considered briefly. There is a quantitative predominance of radionuclide diagnostic studies in pediatric urology compared to studies in oncology....
The program of development and implementation of new diagnostic and therapy technologies based on the Proton Therapy Complex (PTC) "Prometheus" is presented. The tasks will be implemented with the close integration of the LPI, MEPhI, Center of Radiology of RF, as well as their Russian and foreign partners.
Modernization of Russian-made proton synchrotron complexes of the Prometheus system is...
As is known, the flash effect in radiotherapy with a dose rate of more than 40 Gy/s makes it possible to destroy tumor cells much stronger than normal cells. Additional prospects for flash therapy are associated with irradiation with protons, since protons and ions make it possible to increase the conformality of irradiation compared to irradiation with light particles. A unique feature of the...
The main principles and requirements for the introduction of medical physics into medicine in the CIS countries were developed by the organizer of the Association of Medical Physicists of Russia and its first president, Professor Valery Aleksandrovich Kostylev, back in the last century. Now there are medical physicists in the Republic of Belarus.
By the Decree of the Ministry of Labor and...
The radioactive (“hot”) particles (HP) production can occur in different nuclear accidents. To date, a large amount of scientific data on radiation exposure of humans and other mammals has been accumulated, but information on radiative effect on the gastrointestinal tract (GIT) by HP is not enough.
The aim of the study was to simulate the HP transfer in the gastrointestinal tract (GIT) of...
Dear collegues,
Attached is my abstract.
This paper describes the main features of newest version of the PIPLAN Proton-Carbon Ion Radiation Therapy Treatment Planning System. The PIPLAN 2021 code [1] was assigned for precise Monte Carlo treatment planning for heterogeneous areas, including lung, head and neck location. Three various computer methods are used to modeling the interactions between the proton and carbon ion beam and the...
Modern requirements for the quality of bioimplants combine the need to ensure not only the necessary osteoinductive potential, adequate structure and mechanical strength, but also guarantees the safety of the recipient due to the high level of sterility of the plastic material.
Among the currently used technologies for the sterilization of biomaterials, radiation exposures occupy an...
Radiation technologies are commonly used in different areas, such as medicine, in treatment of tumors, radioecology, to ensure radiation safety of the natural environment, and agriculture, to combat with pests and stimulate the growth of crops. Moscow State University (MSU) is currently focusing on five aspects of research in food irradiation.
Our researchers are particularly involved in the...
NIITFA is participating in development of new fast neutron machine for external beam therapy. It’s based on C-arm gantry and D-T neutron generator. So overall design is very close to conventional x-ray LINACs and rises similar problems of dose calculation. Due to unavailability of commercial treatment planning systems (TPS) for fast neutron dose calculation, development of new TPS has been...
At present, NIITFA is developing a new medical device for fast-neutron radiotherapy based on the 14.1 MeV neutron source NG-24[1].
The neutron source NG-24 was simulated in the Topas MC Geant4 environment. The simulation result was compared with the previously obtained result from the MCNP code[2].
A Python console program for running multiple Topas simulations has been developed. The...
Proton flash therapy with high dose rates is at the forefront of cancer treatment. The phenomenon of flash effect is to reduce the damage to normal cells with an extreme dose rate increase of over 40 Gy/s.
Radiobiological experiments aimed at studying this phenomenon may require a special dosimetry equipment [1].
Our work consisted of the formation system settings [2] including the...
The advantages of proton therapy make it useful for treating tumors located in the regions that surround radiosensitive tissues and, in the tissues, where surgical access is limited [1]. Recent studies [2-3] have indicated that Proton-Boron Capture Therapy (PBCT) induces tumor cell death through three alpha particles via the reaction between proton and 11B. When a proton reacts with boron...
Proton therapy is currently attracting additional interest from specialists due to the possibility of using some proton accelerators in the FLASH mode with a dose rate of more than 40 Gy/s. The FLASH effect opens up new advantages for radiation therapy due to the predominant destruction of tumors. The proton beam facility at the INR of RAS makes it possible to achieve a record mean dose rate...
There are situations at prolonged treatment when patient loses weight, tumor changes its size or new lesions appear. In this case adaptive radiation therapy (ART) is necessary. This concept takes into account the changes of patients’ parameters and involves the recalculation of the treatment plans using new set of images. In this phantom study the ART method with using cone-beam computed...
External beam radiotherapy based on volumetric modulated arc radiotherapy technic delivery is widely used for the treatment of the locally advanced head-and-neck cancer (LAHNC). There are some approaches of irradiation of LAHNC, for example, simultaneous integrated boost (SIB) and sequential boost (SEQ) [1]. Analysis of the developed treatment plans based on tumour control probability (TCP)...
Currently, verification phantoms for the verification of radiation therapy plans represents a rectangular or cylindrical solid body made of water-equivalent material with a rectangular hole for inserting a matrix detector. The most famous examples are the MULTICube phantom [1], which is a rectangular solid body made of plastic water (water equivalent with an error of ≤ 0.5%), which has several...
Purpose of the work. a comparative analysis of radiation therapy (RT) plans with simultaneous dose escalation for prostate tumors in the application of biological and physical optimization functions.
Research methods. In this research, dosimetric plans with volumetric modulated arc therapy (VMAT) were developed for nine patients diagnosed with prostate cancer in the Simultaneous integrated...
The objectives of this work are: measurement of the data set of coefficients of radiative output (Output Factors - OF) using five detectors and data validation; determine how OF changes when using two types of field formation, namely, collimator shutters and a multileaf collimator (MLC); investigate the dependence of the output factors on the source-to-surface distance (SSD) and measurement...
Dosimetric planning of radiation treatment using positron emission tomography (PET) images is a promising area that has received special attention in recent years [1]. The PET/CT method makes it possible to improve the accuracy of determining the boundaries of the irradiation volume. However, the use of PET images for radiotherapy planning complicates the low spatial resolution (compared to CT...
Positron emission tomography (PET) is a modern radionuclide method of medical imaging which allows to quantitative estimate of radiopharmaceuticals distribution in vivo. PET is based on the injection of radiopharmaceuticals labeled with ultrashort-lived positron-emitted radionuclides.
Image quality in PET depends on physical characteristics of radionuclide, technique parameters of scanner,...
In clinical practice, and especially in stereotactic radiosurgery planning, the significance of diffusion-weighted imaging (DWI) [1] is growing. This makes the existence of software capable of quickly processing and reliably visualizing diffusion data, as well as equipped with tools for their analysis in terms of different tasks.
We are developing the «MRDiffusionImaging» software on the...
MRI images have been increasingly used in radiotherapy planning in recent years. They have better soft tissues contamination in comparison with CT scans. This is used effectively in the irradiation of soft tissue tumors and especially brain tumors. However, geometric distortions have an impact on dose delivery accuracy when MRI is used in LT. MRI distortion is a particularly acute problem...
New results of a study aimed at developing a method for upgrading existing medical electron accelerators, which can become a real-time method for assessing the dose distribution in the patient's body during irradiation, are presented [1,2]. The paper presents the idea of creating a mathematical model that makes it possible to estimate the distribution of the absorbed dose in the studied tissue...
The relevance of research on the creation of new, effective and safe approaches to the sterilization of bioimplants is beyond doubt due to the high prevalence of diseases and the growth of traumatic injuries of the bone and joint apparatus. The maximum reduction of the radiation dose, elimination of the side effects of radiation, as well as ensuring absolute sterility of the transplant is an...
The study of dose leakage is a vital topic because the number of patients who have developed delayed radiation injuries is increasing every year [1].
The linear accelerator Varian Halcyon V1.0 (Varian Medical Systems, Palo Alto, California, USA) [2] without collimation shutters has recently been put into operation and is now gaining popularity in oncology clinics. The Halcyon MLC system...
Bremsstrahlung obtained during the operation of medical linac is used in the treatment of various types of cancer. At photon energies above 8 MeV, secondary neutrons are produced as a result of photonuclear reactions. This radiation is able to cause additional dose load on the patient, as well as unacceptable working conditions for personnel.
The contribution to the dose due to secondary...
INCREASING THE UNIFORMITY OF RADIATION TREATMENT UNIFORMITY OF OBJECTS USING MODIFIER PLATES
Studenikin F.R. 1,2, Bliznyuk U.A. 1,2, Chernyaev A.P. 1,2, Borshevskaya P.Yu. 1,2, Ipatova V.S. 2, Nikitchenko A.D. 1, Zolotov S.A. 1, Hankin, V.V. 2, Krusanov G.A.3.
1 Physics Department, Moscow State University, Moscow, 119234 Russia
2 Skobeltsyn Institute of Nuclear Physics Lomonosov...
Radiation treatment of food products with properly chosen physical and technical characteristics of radiation (type of radiation, dose, dose rate, etc.) effectively increases the microbiological safety of products, preserving their taste and nutritional properties.
Changes in organoleptic properties of chilled meat products after radiation treatment are related to the degree to which ionizing...
The report presents the advantages and disadvantages of using semiconductor detectors in diagnostic nuclear medicine. The possibilities of using joint SPECT/CT studies using hybrid pixel detectors of the Timepix family are demonstrated.
M. $Lifanov^1$*, S. $Potashev^{1,2}$, Yu. $Burmistrov^1$, V. $Ponomarev^1$
$^1$ Institute for Nuclear Research of Russian Academy of Sciences, Moscow
$^2$ P.N. Lebedev Physical Institute of the Russian Academy of Sciences Moscow
*E-mail: mikelifanov@bk.ru
Depth distribution of ionization losses by electron beam from the output channel at angle of $270^o$ of LUE-8 accelerator is...
This report describe the current stage of developing a new multi-energy X-ray tomograph, which based on hybrid semiconductor pixel detector Widepix. The Widepix analyser software was written for processing the data of the detector during this work.
The Widepix detector is one of Medipix series detectors, which are hybrid semiconductor pixel detectors developed by the Medipix collaboration....
Recently the opportunity of using metalloorganic perovskites as a basic material for semiconductor detectors of ionizing radiation was demonstrated [1]. Presence of lead atoms make possible appearance of small size devices intended for personal dosimetry purposes. Crystal growing from solutions provides low cost of these devices [2]. Chlorine substituted methilammonium lead bromide perovskites...
Optimized Conformal Total Body Irradiation (OC-TBI) is very complex and unique method of radiotherapy. It include irradiation of the whole body with dose of 12 Gy, except organs at risk: lungs, kidneys, liver and lenses. Because of its complicity, we need to pay attention to dose delivery in this method.
The evaluation of the delivered dose for patient received OC-TBI on TomoTherapy can be...
Cosmogenic radionuclide 7Be is frequently used as an atmospheric tracer. Air concentrations or deposition rate of 7Be are usually measured at limited number of locations equipped with air samplers or depositional collectors. Mosses that do not have root system but receives and retains nutrients from the atmosphere can be used as natural filters that provide very good spatial resolution of...
Currently, an indirect method of measuring the volumetric activity of Rn-222 in an aqueous medium, which is measured in liquids by depositing its daughter decay products or by bubbling liquid, is used to analyze samples of water bodies of regions with a naturally elevated level of radiation and its effect on the human body. These methods have a number of disadvantages, such as low particle...
The analysis of the dosimetric pattern and experimentally established biological effects of internal irradiation of monogastric animals (rats, guinea pigs, piglets) is presented "hot" radioactive particles (RP) that cause ulcerative necrotic lesions of the gastrointestinal tract (GIT). Mathematical models of RP transport (in the GIT) and the formation of absorbed doses of β-radiation on the...
The electron energy spectrum is one of the important parameters in electron beam radiation treatment planning for accurate calculation of the dose-volume distribution of the irradiated object. Existing methods such as Monte-Carlo modeling of the radiation source and radiation geometry and direct measurement of the energy spectrum using special equipment are time consuming and expensive,...
These days radiation treatment of objects and materials has been increasingly used in various areas of the national economy. For a number of categories of objects narrow radiation dose ranges are prescribed. Exceeding the upper limits of this range has a negative effect on physical and chemical properties of the object. Going beyond the lower limits does not reach the desired treatment...
$^{161}$Tb is a medical isotope that is considered in therapy as an alternative to the widely used $^{177}$Lu. Currently, the main way of production of this radionuclide is the reactor method based on the neutron capture reaction followed by β-decay: $^{160}$Gd(n,γ)$^{161}$Gd→$^{161}$Tb. However, in this case it is necessary to use expensive enriched targets. This disadvantage is the reason...
The method of induced activity was used to study photonuclear reactions on a natural mixture of selenium isotopes. The experiment was performed on a bremsstrahlung of an RM-55 electron accelerator at an electron energy of 55 MeV. The study examined the possibility of producing 72As isotope in photonuclear reactions on a natural mixture of selenium isotopes. Experimental data on the...
The 82Rb isotope has found application in medicine, where it is used to diagnose diseases of the heart and blood vessels. Being a biological analogue of kalium, rubidium is absorbed by tissues, after which the absorption pattern is visualized by positron emission tomography. A very short lifetime forces the use of mobile 82Rb generators, in which the isotope is produced during the decay of...
Over the last twenty years targeted alpha therapy has demonstrated its high efficiency in treating various oncological diseases. 212Pb, with its convenient half-life of 10.64 h, and its daughter alpha-emitter short-lived 212Bi (T1/2 = 1 h), provides the possibility for the synthesis and purification of radiopharmaceuticals with minimum loss of radioactivity during preparation. It can be milked...
²¹²Pb radionuclide generator with ²²⁸Th as a parent radionuclide has been developed. The generator principle is based on diffusion of gaseous ²²⁰Rn emanating from strong anion exchange resin containing ²²⁸Th into a separate collector where post-decay ²¹²Pb is deposited on the collector walls. After a 48-hour operation cycle of the generator, sampling of ²¹²Pb in the form of solution in 0.1 M...
Secondary obliteration of the lacrimal duct obstruction (SALDO) is one of radioiodine therapy complications in differentiated thyroid cancer observed in 9% of cases [1]. Development of methods for the prevention of SALDO one of the urgent tasks facing radiology and ophthalmology [2]. We analyzed the frequency of 131-iodine uptake nasolacrimal ducts in 203 patients on 72 h. after 131-iodine...
Inaccuracies in brachytherapy treatment occur due to two reasons mainly: anatomical misalignment or as a result of errors that are usually associated with incorrect positioning of the applicator or radiation source during treatment. The purpose of this work is to test the degree of inconsistency in the positioning of the radiation source at the most distant position of the ring applicator when...
