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Biomedical subjects

V S Khoroshkov

Publications and source records attributed to V S Khoroshkov.

12 recordsLinked to original sources
PubMed2002

Proposed double-layer target for the generation of high-quality laser-accelerated ion beams.

In order to achieve a high-quality, i.e., monoenergetic, intense ion beam, we propose the use of a double-layer target. The first layer, at the target front, consists of high-Z atoms, while the second (rear) layer is a thin coating of low-Z atoms. The generation of high-quality proton beams from the double-layer target, irradiated by an ultraintense laser pulse, is demonstrated with three-dimensional particle-in-cell simulations.

Ions↗
PubMed1997

[Hospital centers of proton radiotherapy--problems and possible solutions].

Principles and scope of application of proton therapy in hospitals are discussed. Main distinctions between the dose distribution of megavolt gamma radiation and that of proton radiation are due to that the latter is totally absent behind the target and energy gradients along the lateral and back site boundaries of the proton irradiation field are high. Data on the operating proton therapy centers and those being designed are presented. The unjustifiably slow rate of integration of the proton technique with clinical practice is due to the time-consuming nature of relevant research. Possible ways and means of obviating the difficulties involved are discussed.

Gamma Rays↗
PubMed1995

Relative biological effectiveness of proton medical beam at Moscow synchrotron determined by the Chinese hamster cells assay.

PURPOSE: Assessment of relative biological effectiveness (RBE) of the proton medical beam at Moscow synchrotron. METHODS AND MATERIALS: The study was performed at Moscow proton medical facility (Institute for Theoretical and Experimental Physics). Relative biological effectiveness of the synchrotron proton beam was assessed at the entry of the unmodulated 179 MeV beam and in the center of spread out Bragg peak (SOBP), from measurements of the survival of Chinese hamster cells (clone 431). Gamma-radiation of 60Co was used as a reference source. RESULTS: According to the linear regression model, mean RBE values at 37% survival level were found to be 1.10 +/- 0.04 at the beam entry and 1.14 +/- 0.05 in the center of SOBP. Values of RBE obtained using the linear-quadratic model for 10% and 37% survival levels were 1.09 and 1.07, respectively, at the beam entry and 1.07 and 1.08, respectively, in the center of SOBP. CONCLUSIONS: The data obtained indicate that (a) the RBE values at the entry of the unmodulated beam and at the center of the SOBP are in close agreement, with an average of about 1.10; (b) protons are radiobiologically somewhat more effective than 60Co gamma rays; and, (c) high pulse dose rate of the medical beam does not significantly affect biological effects of the beam.

Animals↗
PubMed1994

Moscow hospital-based proton therapy facility design.

An innovative design for a hospital-based proton therapy facility is described here in two versions: a single level (3600 m2) and a three-level plan (700-720 m2). The facility is designed to have 5 to 6 treatment rooms working simultaneously and independently of each other. The accelerator is a 250 MeV H-synchrotron, which produces a small external beam capable of pencil-beam scanning treatments. The small emittance of the beam yields cost savings in the size and weight of the magnets and the amount of concrete shielding. The beam delivery systems, including an isocentric gantry, are designed to use elements that are well known and thoroughly tested. Initial cost of a facility using this new design is estimated to be only 25-30% higher than construction of a facility delivering conventional photon treatments.

Cancer Care Facilities↗
PubMed1988

Medical proton accelerator facility.

This paper presents a specialized medical accelerator facility designed for proton radiation therapy and for production of short-lived nuclide-labelled radiopharmaceuticals. General features of the facility structure, the choice of principles of beam delivery, physical and technical problems connected with clinical work, and biomedical research are discussed.

Facility Design and Construction↗
PubMed1987

[3-unit complex for proton therapy].

Since 1969 proton beam therapy of patients with different types of diseases using the ITEP synchrotron proton beam with the energy up to 200 MeV has been conducted in a number of Moscow medical centers. These irradiations employing a specially formed beam are used on a routine basis and are performed in parallel with the program of physical research. Two additional channels as well as two new procedure rooms have been in operation since 1982. A special setup of equipment including clinical dosimetry devices, equipment for patients' irradiation (4 special units), and computer-controlled systems have been installed at the facility. By the present time over 1300 patients have been irradiated. The authors describe physical and dosimetric equipment and irradiation techniques. A summary table containing data on the patients is provided.

Facility Design and Construction↗
PubMed1987

[Topographic and dosimetric considerations in different methods of proton irradiation].

Two techniques are employed for proton irradiation: one--to pass a proton beam through a target, the other one--to stop in it. The advantage of the first technique is a very small angular divergence of the beam penetrating tissues or, consequently, a very high lateral edge field gradient. The second technique has two additional advantages: the absence of radiation lesions behind the target and an increase in the stopping power (dose) at the end of the beam range localized in the target. The authors present their considerations concerning the applicability of each technique and certain characteristic problems of the second technique. Dose field deformations as a result of topometric uncertainties are also estimated. A method of dose design aimed at minimizing the above mentioned effect is proposed.

Humans↗
PubMed1987

[Spiral comb filter].

The paper is concerned with some considerations on ridge filters used for proton beam therapy. Such filters are able to transform the beam energy spectrum and the corresponding Bragg curve defining proton beam depth dose distribution. Some difficulties in the manufacture of ridge filters are discussed. The authors describe a ridge filter design which is simple and fit for continuous production. An account of a calculation method and production process is given.

Filtration↗