RU2428228C2 - Radiation protector for biological objects in experiment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to devices for laser irradiation of biological objects when exposed to damaging effect of ionising radiation in experiment. The device comprises an emitter and an adapter supply unit. The emitter consists of a laser module at wave length 650 nm and a concave lens. Between the supply unit and the emitter, there is a variable resistor. On a supply input, there is a timer connected to the adapter. The timer sets time providing irradiation of biological objects by laser irradiation dose 1 mJ/cm².

EFFECT: use of the device allow irradiating the objects in a precise effective dose.

Description

The invention relates to medicine and can be used for local protection of biological objects, i.e. for radioprotection of any area of the body, in particular the skin or mucous membranes of the nasal or oral cavity. Such a need often arises in the process of radiation therapy or surgery for cancer. Such protection may also be needed in some industrial situations when some part of the human body was accidentally exposed to ionizing radiation with a large linear transfer of energy (LET), such as alpha particles, which penetrate into the body shallowly.

The invention is known "METHOD OF PROTECTION IN AN EXPERIMENT AGAINST THE HARMFUL ACTION OF IONIZING RADIATION" (patent for invention D1 RU 2330695 C2, 08/10/2008). The essence of this invention is that to protect against the damaging effects of ionizing radiation, the fibroblast cells were irradiated with a helium-neon laser. A helium-neon laser with a radiation power of 0.5 mW was used as a source of laser radiation. The radiation wavelength is 633 nm. The diameter of the laser beam was 4.4 cm. The radioprotective effect of the laser is observed in a certain rather narrow range of energy density, and the maximum effect is observed when the laser energy density is about 1 mJ / cm ² .

When implementing this method a number of inconveniences arose. The first of these was associated with the use of a helium-neon laser, which is a gas laser [1]. The disadvantages of these lasers are their high cost, the fragility of the radiation sources, the large size and weight of the devices. The diameter of the laser beam is narrow, and to irradiate large surfaces, it was necessary to expand the beam using an optical scattering lens. In addition, whenever a change in the size of the laser beam was necessary, a new calculation was needed to obtain the necessary optimally effective dose. Based on the laser power and beam diameter, the exposure time was calculated to obtain the desired dose. Since the irradiation time was monitored using a stopwatch, and the laser was turned on and off manually, it is obvious that errors in the radiation dose were possible. Another inconvenience was that there was no possibility of spatial redirection of the laser beam, since for this it was necessary to simultaneously move the laser and the optical lens.

The aim of this invention was to eliminate the disadvantages of the prototype, namely to eliminate errors in the radiation dose and create a convenient device in use with the possibility of spatial redirection of the laser beam.

The obtained results, which showed that in order to exert a radioprotective effect on biological objects using laser radiation with a wavelength of 633 nm, it was not necessary to irradiate the entire surface of biological objects in need of radiation protection [2]. In this work, a monolayer of fibroblast cells grown on the wall surface of a plastic bottle was subjected to gamma radiation, then the entire surface of the bottle wall (25 cm ² ) or only its central part with an area of 1 cm ^{2 was} irradiated with laser radiation (to study the possibility of transmitting the radioprotective effect of the laser radiation by type "bystander" [3] effect). The experiments showed that regardless of the size of the surface of the monolayer of cells irradiated with a laser, almost the same radioprotective effect of laser radiation is observed. These results show the possibility of transmitting the radioprotective effect of laser radiation by the mechanism of the "bystander" effect. The data obtained eliminate the problems encountered in practice related to the large size of the surface of biological objects affected by ionizing radiation, since they allow us to divide this surface into 25 cm ² segments and for radiation protection only 1 cm ² from each segment can be irradiated with a laser. Therefore, for prophylactic irradiation of biological objects with laser radiation of the red spectral region, it is not necessary to expand the laser beam to the size of the damaged surface or to scan the entire damaged surface with a laser beam.

The essence of the proposed solution lies in the fact that in the device for laser irradiation of biological objects with the damaging effect of ionizing radiation on them in an experiment containing an emitter consisting of a laser module with a wavelength of 650 nm and a scattering lens, the power supply is an adapter between the power supply and the emitter there is a variable resistor that fixes the radiation power of the laser module, and at the power input of the device there is a timer associated with the start button and connected to the adapter input by executive ontacts, at which the time was established, which ensures the irradiation of biological objects with a laser radiation dose of 1 mJ / cm ² at a certain distance of the emitter from the irradiated object indicated on the device.

The use of all these components led to the following positive effect: there is no need to carry out any calculations, all calculations have already been made by the manufacturer, no auxiliary devices are needed. The user only has to observe the distance indicated on the device between the emitter and the biological object. Due to the small size of the emitter and the fact that the scattering lens is built into the emitter, it is possible to freely vary the direction of the laser beam in space.

The proposed device allows for the irradiation of biological objects with a radioprotective dose of laser radiation, just press the start button. The device provides an expanded laser beam, a laser dose of 1 mJ / cm ² and turns off automatically. It has a small size and low cost.

Figure 1 shows the proposed scheme of a device for the prevention of biological objects in radiation injuries in an experiment, where

1 - timer;

2 - Power supply - adapter;

3 - Start button;

4 - Variable resistor;

5 - Laser module;

6 - Laser emitter housing;

7 - Scattering lens.

The device operates as follows. Before starting the device is in standby mode, the timer (1) and the network adapter (2) are de-energized. When the “start” button (3) is pressed, the voltage of the industrial network ≈ 220 V is applied to the timer relay, as a result of which the relay contacts are switched, which close the power supply circuit of the adapter. The output voltage of the +4 V adapter is supplied through a variable resistor (4) to the laser module (5), which is located in the laser emitter housing (6). The laser module begins to generate optical radiation, which, passing through the scattering lens (7), leaves the emitter. After counting the set time, the timer is turned off, and the voltage supply to the laser module is stopped.

The presence of a scattering lens in the emitter provides at the exit from it an expanding laser beam having different sizes depending on the distance from the emitter.

The presence of a variable resistor allows you to fine-tune and fix the radiation power of the laser module.

The presence of a timer with a fixed fixed exposure time makes it possible to irradiate biological objects precisely at a dose of 1 mJ / cm ² while observing the distance from the emitter indicated on the device by the manufacturer.

The device indicates the distance from the emitter to the biological object at which the value of the laser beam area (S) provides the necessary energy density (P) with the available laser radiation power (J) and laser irradiation time (t). The formula of the relationship between the above parameters:

S = tJ / P, where t is the laser irradiation time, S = πr ² is the laser beam area at the irradiation point, J is the radiation power, and P is the energy density.

Figure 2 presents a photo of a specific implementation of this device.

In this sample device used:

steel laser emitter housing;

laser module - IE75-05PF;

plexiglass optical lens with a diameter of 6.5 mm;

holder for a radiator - IE-200;

timer - TH3D-NA 1-999 s;

power supply - adapter - ROBITON SN 1000S (1.5-12 V, 1 A, 12 W);

variable resistor - SP - 1VA.

To measure the power of the emitter used a laser power meter LP 1.

In this version, the device emits laser radiation with a power of 0.7 mW and allows a distance of 64 cm from the emitter (the diameter of the laser beam expanded with a scattering lens at the irradiation point is ~ 2.6 cm) in 8 seconds to irradiate the biological object in the dose necessary for radiation protection in 1 mJ / cm ² .

Also made instrument version of the device for use in practice (figure 3), where the main part of the device is placed in a plastic case. Only the start button and the front of the timer are placed on the control panel (for the possibility of monitoring the health of the timer). The emitter is built into the housing of the hand torch, which is connected to the rest of the device with a long electric cable, allowing maneuvering the emitter in space (direction of the laser beam). On the body of the flashlight there is a button for turning on the laser module, which can only work after pressing the "start" button on the device. This technical solution allows, if necessary, irradiation with the aim of radioprotective exposure to laser radiation of a large number of segments of a biological object to freely move the emitter and only press the power button on the emitter.

The operation of the device was successfully tested on C57BL / 6 mice.

It is well known that radiation damage to the blood-forming organs plays an important role in the development of radiation sickness in humans and animals [4]. The most characteristic are a decrease in the number of lymphocytes (radiation leukopenia) and bone marrow karyocytes. For this reason, the search for ways to improve the restoration of blood formation after exposure to the body of ionizing radiation is an important task for radiation protection.

In this regard, experiments were conducted to study the effect of combined irradiation with laser radiation and ⁶⁰ Co gamma rays (3 Gy) on the level of hemoglobin and peripheral blood leukocytes and bone marrow karyocytes in experimental C57BL / 6 mice. When the mice were irradiated with ionizing and laser radiation, they were placed one by one in special machines. The time interval between the two types of irradiation did not exceed 30 minutes. First, the mice were exposed to γ-radiation, then they were irradiated with a laser device for irradiating biological objects under the damaging effect of ionizing radiation on them in the experiment. Laser radiation (at a dose of 1 mJ / cm ² ) did not irradiate the entire body of the mice, but only the hairy back. The area of the expanded beam at the irradiation point was ≈ 5.3 cm ² (approximately 1/3 of the back surface). The experimental results showed that 15 days after the mice were irradiated with γ-rays, the quantitative content of hemoglobin in their blood was restored, but the values of the number of leukocytes and karyocytes of the bone marrow are still lower than in intact mice. However, in mice combined with gamma rays and laser radiation, the number of marrow karyocytes on the 15th day after irradiation is already at the level of intact mice. Consequently, the device of laser irradiation of biological objects under the damaging effect of ionizing radiation on them in the experiment can be used to improve the restoration of hematopoiesis after exposure to biological objects of ionizing radiation [5, 6].

The effectiveness of the preventive effect of this device is also illustrated by the following clinical examples.

Under the influence of ionizing radiation on animals and humans, damage to their skin is observed [7], which leads to radiation (radiation) burns (radioepidermitis). Burns are usually observed after a single action of large doses of ionizing radiation, in some cases - after repeated irradiation of the skin with “hard” and filtered rays in therapeutic doses. Radioepidermitis, which is accompanied by a sensation of itching and tension of the skin, is widespread and is a serious problem in people undergoing radiation therapy to treat cancer. Therefore, a device for the prevention of biological objects in radiation injuries was used to protect the skin of patients undergoing radiation therapy in the treatment of cancer.

Example 1. Patient B., 50 years old. Received in the surgical department of the Federal State Health Institution MSCh No. 9 FMBA of Russia, with a direct diagnosis - cancer of the left breast. It was operated on 03/18/2009.

05/13/09, was admitted to the radiological department of the Federal State Healthcare Institution MSCh No. 9 FMBA for the passage of remote radiation gamma-therapy in a total dose of 50 Gy.

Irradiation was carried out in the Medical and Technical Complex (MTK) of the Laboratory of Nuclear Problems (DLNP) of the Joint Institute for Nuclear Research (JINR) in Dubna according to the generally accepted scheme: 2 Gy per day, five days a week. Irradiated zone: parasternal on the right (56 cm ² ), supraclavicular on the right + axillary on the right (180 cm ² ), right mammary gland - medial field (96 cm ² ) and lateral field (96 cm ² ). After irradiation at a dose of 10 Gy, the patient began to have redness of the skin and itching in the irradiation area, and the postoperative scar was ill. The patient did not sleep well. The ointment “Methyluracil” prescribed by the radiologist practically did not contribute to the improvement of the patient’s skin condition. In this regard, after irradiation in a total dose of 30 Gy (from 13.05.09 to 02.06.09), by decision of a radiologist, gamma therapy was temporarily suspended (from 03.06.09 to 06.22.09 g .). After a break in irradiation, the patient's skin did not completely recover. On the recommendation of a doctor and with the consent of the patient, from 06.22.09 until the end of the course of radiotherapy (03.07.09), the patient after irradiation with gamma rays (after 10-20 minutes) was irradiated with a laser device. The surface area irradiated with gamma rays was approximately 428 cm ² . When irradiated with a laser device, the affected area of the skin was divided into segments ~ 25 cm ² in size and 5.3 cm ^{2 was} irradiated from each segment for radiation protection (this value corresponds to the area of the laser beam at the irradiation point at a distance of 64 cm from the patient). Irradiation of one segment lasted 8 seconds. The whole procedure (taking into account the time for changing the direction of the laser beam) took no more than 4 minutes. Starting from the first day of laser irradiation, damaged skin gradually began to recover, itching was not observed.

Example 2. Patient A., 34 years old. Received in the surgical department of the Federal State Healthcare Institution MSCh No. 9 of the FMBA of Russia, with a direct diagnosis from ONTs RAMP them. Blokhin - leiomyosarcoma of the axillary region on the right. 08/25/2009 was operated.

09/23/09 was admitted to the radiological department of the Federal State Healthcare Institution MSCh No. 9 FMBA for the passage of remote radiation gamma therapy in a total dose of 52 Gy. Irradiation was carried out in the MTK LNP JINR according to the above scheme. Irradiated zones: right axillary region. After irradiation at a dose of 6 Gy, the patient already had skin hyperemia and itching in the irradiated area, and the postoperative scar was ill. The ointment “Solcoseryl” prescribed by the radiologist, as in the above example, did not contribute to the improvement of the patient’s skin condition. After irradiation in a total dose of 30 Gy (from 09/23/09 to 10/13/09), by decision of a radiologist, gamma therapy was temporarily suspended (from 10/14/09 to 10/26/09 inclusive). Since the patient’s skin still has not recovered after a break in irradiation, on the recommendation of a doctor and with the consent of the patient from 10/27/09 to the end of the course of radiotherapy (11/11/09), the patient after irradiation with gamma rays (after 10-20 minutes) was irradiated with device. The surface area irradiated by gamma rays was approximately 112 cm ² . The irradiation of the entire affected surface with a laser device, carried out according to the above scheme (taking into account the time to change the direction of the laser beam), took no more than 1.5 minutes. Starting from the first day of laser irradiation, damaged skin gradually began to recover, itching was not observed.

LITERATURE

1. Gas lasers (under the editorship of NN Sobolev). - M. Publishing House "Mir", 1968

2. K.Sh. Voskanyan, G.V. Mitsyn, V.N. Gaevsky. Some features of the combined effect of gamma rays and laser radiation on the survival of murine fibroblasts in vitro // Aerospace and Environmental Medicine, 2009, v. 43, No. 2, p. 32-37.

3. Hall E.J. The bystander effect // Health Phys. 2003. Jul; 85 (1). P.31-35.

4. Yu.B. Kudryashov, B.S. Berenfeld. Fundamentals of radiation biophysics. - Publishing House of Moscow University, 1982

5. KSVoskanyan, GVMitsyn, VNGaevsky, SVVorojtsova, ANAbrosimova. Modification of the action of gamma radiation on the peripheral blood parameters and on the number of bone marrow karyocytes of c57bl / 6 mice with the help of red spectral range laser radiation // Abstracts of the 38 ^th Annual Meeting of the European Radiation Research Society. Stockholm, 5-9 September, 2010. P.185.

6. K.Sh. Voskanyan, S.V. Vorozhtsova, A.N. Abrosimova, G.V. Mitsyn, V.N. Gaevsky, K.N. Shipulin. Modification of the effect of gamma radiation on peripheral blood parameters and the number of bone marrow karyocytes in mice by laser radiation in the red spectral region // Aerospace and Environmental Medicine, 2010 - in print.

7. Gerasimova L.I. Thermal and radiation burns. - Moscow. Publishing House "Medicine", 2005

Claims (1)

A device for laser irradiation of biological objects under the damaging effect of ionizing radiation on them in an experiment, including an emitter and a power adapter, characterized in that the emitter consists of a laser module with a wavelength of 650 nm and a scattering lens, while an alternating variable is located between the power supply and the emitter a resistor, and at the device’s power input there is a timer connected to the adapter, on which the time is set to ensure irradiation of biological objects with a laser dose of 1 mJ / cm ² .

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