Life style and risk of development of dental caries in a population of adolescents

Introduction. Oxygen is an essential element for sustaining the life of aerobes; however, in certain conditions it may be toxic for these organisms. This is due to so-called reactive oxygen species – ROS. Factors which cause the production of free radicals include ionizing radiation, UV radiation, high temperature, and hazardous substances, such as phenols, carbon monoxide, e.g. in smokers, also air pollution and drugs. Objective. The objective of the study was analysis of the total antioxidant status (TAS) in stimulated and unstimulated saliva, according to the number of active carious lesions in generally healthy non-smokers aged 15–17. Materials and method. The study covered 113 adolescents aged 15–17 in whom the state of dentition was evaluated using the DMFT (Decayed-Missing-Filled) index, and oral hygiene assessed based on the OHI-S (Oral Hygiene Index-Simplified) index. TAS in saliva was determined by means of a Randox Labolatories Ltd. test kit, by the spectrophotometric method. Results. Based on the results of the study, it was found that in the population examined an increase in the number of carious lesions was accompanied by a significant decrease in the TAS, both in stimulated and unstimulated saliva. Conclusions. A health-promoting life style, maintenance of basic principles of oral hygiene and care of general health through the elimination of harmful habits decrease the risk of dental caries

Ultra-Hypofractionated Proton Therapy in Localized Prostate Cancer: Passive Scattering versus Intensity-Modulated Proton Therapy

Few studies have directly compared passive scattering (PS) to intensity-modulated proton therapy (IMPT) in the delivery of ultra-hypofractionated proton beams to the localized prostate cancer (PCa). In this preliminary study involving five patients previously treated with CyberKnife, treatment plans were created for PS and IMPT (36.25 CGE in five fractions with two opposing fields) to compare the dosimetric parameters to the planning target volume (PTV) and organs-at-risk (OAR: rectum, bladder, femoral heads). Both plans met the acceptance criteria. Significant differences were observed in the minimum and maximum doses to the PTV. The mean dose to the PTV was lower for PS (35.62 ± 0.26 vs. 37.18 ± 0.14; p = 0.002). Target coverage (D98%) was better for IMPT (96.79% vs. 99.10%; p = 0.004). IMPT resulted in significantly lower mean doses to the rectum (16.75 CGE vs. 6.88 CGE; p = 0.004) and bladder (17.69 CGE vs. 5.98 CGE p = 0.002). High dose to the rectum (V36.25 CGE) were lower with PS, but not significantly opposite to high dose to the bladder. No significant differences were observed in mean conformity index values, with a non-significant trend towards higher mean homogeneity index values for PS. Non-significant differences in the gamma index for both fields were observed. These findings suggest that both PS and IMPT ultra-hypofractionated proton therapy for PCa are highly precise, offering good target coverage and sparing of normal tissues and OARs

Wax boluses and accuracy of EBT and RTQA radiochromic film detectors in radiotherapy with the JINR Phasotron proton beam

AimTo present the results obtained using radiochromic films EBT and RTQA 1010P for the reconstruction the dose distributions for targets irradiated by proton beam and modified by wax boluses.BackgroundIn Medico-Technical Complex at the Joint Institute for Nuclear Research in Dubna implemented technology of wax boluses.Materials and methodsWax boluses are easier to make and they give better dose distributions than boluses made from modeling clay previously used at our center. We irradiated two imaginary targets, one shaped as a cylinder and the other one as two cuboids. The evaluated calibration curve was used for calculation of the dose distributions measured by the EBT and RTQA radiochromic film. In both cases, the measured dose distributions were compared to the dose distributions calculated by the treatment planning system (TPS). We also compared dose distributions using three different conformity indices at a 95% isodose.ResultsBetter target coverage and better compliance of measurements (semiconductor detectors and radiochromic films) with calculated doses was obtained for cylindrical target than for cuboidal target. The 95% isodose covered well the tumor for both target shapes, while for cuboidal target larger volume around the target received therapeutic dose, due to the complicated target shape. The use wax boluses provided to be effective tool in modifying proton beam to achieve appropriate shape of isodose distribution.ConclusionEBT film yielded the best visual matching. Both EBT and RTQA films confirmed good conformity between calculated and measured doses, thus confirming that wax boluses used to modify the proton beam resulted in good dose distributions

Ultra-Hypofractionated Proton Therapy in Localized Prostate Cancer: Passive Scattering versus Intensity-Modulated Proton Therapy

Few studies have directly compared passive scattering (PS) to intensity-modulated proton therapy (IMPT) in the delivery of ultra-hypofractionated proton beams to the localized prostate cancer (PCa). In this preliminary study involving five patients previously treated with CyberKnife, treatment plans were created for PS and IMPT (36.25 CGE in five fractions with two opposing fields) to compare the dosimetric parameters to the planning target volume (PTV) and organs-at-risk (OAR: rectum, bladder, femoral heads). Both plans met the acceptance criteria. Significant differences were observed in the minimum and maximum doses to the PTV. The mean dose to the PTV was lower for PS (35.62 ± 0.26 vs. 37.18 ± 0.14; p = 0.002). Target coverage (D98%) was better for IMPT (96.79% vs. 99.10%; p = 0.004). IMPT resulted in significantly lower mean doses to the rectum (16.75 CGE vs. 6.88 CGE; p = 0.004) and bladder (17.69 CGE vs. 5.98 CGE p = 0.002). High dose to the rectum (V36.25 CGE) were lower with PS, but not significantly opposite to high dose to the bladder. No significant differences were observed in mean conformity index values, with a non-significant trend towards higher mean homogeneity index values for PS. Non-significant differences in the gamma index for both fields were observed. These findings suggest that both PS and IMPT ultra-hypofractionated proton therapy for PCa are highly precise, offering good target coverage and sparing of normal tissues and OARs