Radiation Protection of Personnel in Contact Radiation Therapy in Ophthalmology

Purpose: To ensure radiation safety of medical staff personal protective equipment (PPE). Material and methods: In order to not make assumptions of possible protective materials optical distortion, estimated the dependence of light transmission in the wavelength range 330–660 nm leaded glass brands of TF-1 and TF-5, as well as the intensity of glow glasses when exposed to light and X-rays. Results: We trace the degree of browning and the nature of the recovery of transparency of glass after irradiation. To determine the optimum thickness of lead glass for eyewear experimentally evaluated attenuation of X-rays with energy efficiency 30 and 80 keV. Lead equivalent values for lead glass, was determined so for Eeff ~ 20 keV at a multiplicity of weakening k = 10 lead glass brand TF-5 thickness 2.0 mm equivalent 0.8 mm Pb, etc. For the possible use of other additives in the window shows the curves of the attenuation of photon radiation radionuclide 241Am (20–60 keV) filters from 9Be, 26Al, 56Fe, 64Cu, 99Mo, 112Cd, 184W, 207Pb Conclusion: Possible introduction of new dose limits for the lens of the eye can be successful only in case of both existing and newly developed PPE. To reduce the impact of domestic lead glass radiation can be used for staff in the form of screens and glasses.

CONTACT RADIATION THERAPY (BRACHYTHERAPY): CLINICAL CONCEPT OF DIRECT DOSIMETRY [IN VIVO] AND QUALITY ASSURANCE OF RADIATION THERAPY

Contact radiation therapy (brachytherapy): the clinical concept of direct dosimetry [in vivo] and quality assurance of radiation therapy the issues of organizing the brachytherapy process with the possibility of confirming the calculated doses obtained on planning systems by direct dosimetry with scintillation small-size dosimeters with the technology of their placement, fixation and visualization are Considered. The coincidence of the calculation data with the measurement results helps to improve quality assurance, especially when using the fractionation mode of a single focal dose of more than 5-6 Gr.

CLINICAL PROBLEMS OF DIRECT DOSIMETRY (IN VIVO) IN CONTACT RADIATION THERAPY

The use of multicomponent methods of special treatment (surgery, polychemotherapy, radiation therapy, laser photodynamic therapy) in oncology requires the control of doses in the tumor and healthy organs with high accuracy. A method of direct dosimetry using fiber-optic scintillation dosimeter MCD-4 is proposed. The dosimeter is fixed on endostats and is visualized on CT/MRI. The coordinates are entered into the anatomical units and dosimetry calculations, the data are mapped, the doses are adjusted on medical grounds. The developed technique of direct dosimetry allows monitoring of the contact radiation therapy (CRT) procedure in real time and making the necessary changes and corrections during the treatment. The refinement of the absorbed dose values using calculations and direct dosimetry minimizes the risk of complications and ensures the possibility of effective use of other treatment methods, including photodynamic therapy, after CRT.

Brachytherapy is a Promising Treatment for Prostate Cancer

– prostate Cancer is one of the most common cancers among men. Incidence is second only to tumors of the broncho- pulmonary system. In recent years significantly increased the interest in contact radiation methods of treatment of this disease (brachytherapy). In the treatment of prostate cancer there is experience of application of different source of dose-rate used sources of low dose (isotopes of iodine (125I), palladium (103Pd) and cesium (131Cs) and sources used for high dose rate (iridium Ir192 or cobalt 60 Co). In Russia the greatest popularity is the use of isotope Ir192 andI125 for brachytherapy. Given indentichnost the indications for treatment, equivalent figures cancerspecifically and relapse-free survival, the question of the choice of treatment is very important. A brief review of the literature on the use of brachytherapy for prostate cancer sources of different dose. Presents comparative characteristics of treatment results, complications, early and late toxic reactions when used brachytherapy isotopes different dose.