Superficial tumours can be treated with megavoltage electron beams. The underlying tissue can be spared through the steep dose fall-off gradients over a range of a few centimetres. An accurate Monte Carlo model for an Elekta Precise was determined and dose distribution was simulated. Dosimetric parameters were calculated to set guidelines for tumour irradiation. Elekta Precise multi-leaf collimators (MLC), which shaped electron fields were investigated using a benchmarked Monte Carlo model. BEAMnrc modelled the Elekta Precise and results were benchmarked against measurements. Percentage depth dose and beam profile data were simulated within 2% / 2 mm accuracy of the measured data. The DOSXYZnrc code simulated the 3-D dose data in water between 4 and 15 MeV. The relative (P80-20) penumbra, percentage depth dose (PDD), range to 90% of dose maximum (R90), dose fall-off range R80-20 (DFR), and the percentage bremsstrahlung dose (BSD), were extracted from the simulated data. The relative penumbra ranged from 90% to 10% at 6 MeV and 15 MeV, respectively. R90 values ranged between 0. 8 cm at 4 MeV and 4. 5 cm at 15 MeV. The DFR ranged between 0. 8 cm at 4 MeV and 3. 5 cm at 15 MeV. The BSD was the highest for low beam energies and small fields. Developed guidelines indicated that intermediate-sized MLC fields are most suited for therapy since they have lower BSD, longer R90, shorter DFR but larger P80-20. The DFR increases and R90 decreases for small fields at higher beam energies and more distal tissue will receive doses > 20%.

Background: The purpose of this study was to inves gate the various gantry angle and SSD dependencies of TLD and MOSFET dosimeters. Materials and Methods: LiF (Mg) TLD and MOSFET were used in this study. Dosimeter systems were calibrated and then irradiated at various gantry angle and SSD by applying 6 MV photon energy. Results: Based on the results, MOSFET changes were found to be in 2% range between ± 50º gantry angles and the rate of dose change was found to be increasing as gantry angle was at the extremes of graph. This increase was especially obvious in tail end of the asymmetric axes. Change in the gantry angle dependency of TLD was-2%  ll ± 60º gantry angle and-5% between 60º to 90º . Dependency of SSD was ± 1% for TLD and MOSFET. Conclusion: Results indicate that proper es of dosimeters must be well known by users for accurate determina on of the en re doses on the pa ent. These observa ons may lead to be4er treatment quality and preven on of probable dose errors.

Introduction: Numerous studies have indicated the role of unexpressed emotions in Somatic Symptoms Disorder (SSD). There are also many studies demonstrating a high prevalence rate of SSD in Iran. Literature suggests that due to cultural issues in Iran, it is difficult directly expressing emotions. Therefore, the issue of emotion expression contributes to a high prevalence of SSD in Iran. To address this issue, the aim of this study was to discover cultural obstacles in emotional expression among patients with SSD in an Iranian sample. Method: A qualitative conventional content analysis was conducted on the data collected from 17 individual in depth interviews with SSD patients, and mental health professionals who were recruited throughout a purposive and theoretical sampling. The sample was derived from the statistical population of SSD patients who were referred to mental health professionals at therapeutic centers in Tehran, Iran. Results: Three themes were emerged as the obstacles of emotion expression in SSD patients in the context of the Iranian culture: 1) Overgenderizing emotions 2) Internalized ban of expressing emotions towards parents and other authorities 3) Difficulties with expressing positive emotions. Conclusion: It seems that SSD patients in Iran have difficulties directly expressing their emotions, regarding the four aforementioned cultural barriers identified in this study.