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Introduction: This study aimed to calculate the photon and neutron doses received to the contralateral breast (CB) during breast cancer radiotherapy for various field sizes in the presence of a physical wedge. Materials and Methods: Varian 2100 C/D linear accelerator was simulated using a MCNP4C Monte Carlo code. Then, a phantom of real female chest was simulated and the treatment planning was carried out on tumoral breast (left breast). Finally, the received photon and neutron doses to CB (right breast) were calculated in the presence of a physical wedge for 18 MV photon beam energy. These calculations were performed for different field sizes including 11 cm × 13 cm, 11 cm × 17 cm, and 11 cm × 21 cm. Results: The findings showed that the received doses (both of the photon and neutron) to CB in the presence of a physical wedge for 11 cm × 13 cm, 11 cm × 17 cm, and 11 cm × 21 cm field sizes were 9.87%, 12.91%, and 27.37% of the prescribed dose, respectively. In addition, the results showed that the received photon and neutron doses to CB increased with increment in the field size. Conclusion: From the results of this study, it is concluded that the received photon and neutron doses to CB in the presence of a physical wedge is relatively more, and therefore, they should be reduced to as low as possible. Therefore, using a dynamic wedge instead of a physical wedge or field-in-field technique is suggested
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Aim: The aim was to measure doses of eyes and lenses in the presence and absence of shield during whole brain irradiation (WBI). In addition, the dose calculations accuracy of radiation therapy dose plan treatment planning system (TPS) in dose calculation of the eyes and lenses in WBI was evaluated. Materials and Methods: To measure the eyes and lenses doses during WBI, an inhomogeneous phantom of human head was used. Then, the eyes and lenses doses in the presence and absence of shield were measured by EBT3 film. Results: In single fraction with 200 cGy to reference point, average doses received by the left and right eyes in the absence of shield were 20 ± 1.5 and 22 ± 1.0 cGy, respectively, and for the left and right eyes in the presence of shield were 18 ± 2.2 and 21 ± 2 cGy, respectively. In addition, the average dose received by the left and right lenses in the absence of shield were 19.5 ± 0.5 and 18.5 ± 0.5 cGy, respectively, and for the left and right lenses in the presence of shield were 20.5 ± 1.5 and 19.5 ± 1.5 cGy, respectively. The results showed the TPS compared to the film underestimates doses for the eyes and lenses. Conclusion: The average dose received by the eyes and lenses during WBI were estimated around 9–11% of prescribed dose. According to the results, there is probability of radiation-induced cataractogenesis during WBI. By investigating the effect of shield on the lenses and eyes doses, using shield during WBI is not recommended. In addition, the results showed dose calculation accuracy of the TPS for the estimation of doses received by the eyes and lenses during WBI is not acceptable
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Objective: Date palm seed extract (DPSE) has various compounds revealing antioxidant features. This study aimed to evaluate the radioprotective effect of DPSE in total body gamma irradiation. Materials and Methods: At first, chemical characteristics of DPSE were analyzed by ultraviolet, visible and Fourier transform infrared spectroscopy. Then, the toxicity of DPSE was assessed. For this purpose, 60 mice were divided into five groups, and each of the groups were injected by the doses of 100, 200, 300, 400, and 500 mg/kg, respectively. At the termination of the experiment, mortality rate and weight loss of all mice were evaluated over a period of 30 days. Finally, the radioprotective effect of DPSE was evaluated by dividing 36 mice into three groups: control, test, and placebo and then were irradiated by Cobalt-60. Results: According to the findings, there was no mortality due to DPSE. Furthermore, for the maximum dose of 500 mg/kg, the number of mice surviving at the termination of the experiment with and without injection of DPSE was reported as 83% and 41%, respectively. In addition, a significant difference was obtained between radiated mice with and without DPSE injection (P = 0.035). Conclusion: The findings showed that DPSE injected into mice before irradiation has no toxicity and could protect mice from lethal effects of total body irradiation. The use of DPSE as a new radioprotector agent in the human needs further studies, particularly clinical trials