introduction: in radiotherapy, methods of treatment planning are becoming increasingly more complicated. this requires verification of the doses delivered to increasingly smaller and more precise regions. radiotherapy techniques are continuously employing smaller and smaller field sizes to deliver tighter radiation doses with higher therapeutic ratios, generating interest among researchers to p...

introduction radiotherapy planning systems require many percentage depth dose (pdd) and profile measurements and there are various dosimeters that can be used to obtain these scans. as dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (efd) in these fields is of interest. the aim of this work was to investigate the ...

Purpose: To investigate the energy dependence/spectral sensitivity of silicon diodes designed for small-field dosimetry and obtain response factors (RFs) for arbitrary photon spectra using Monte Carlo (MC) simulations.   Methods: The EGSnrc user-code DOSRZnrc was used to calculate the dose deposition in water and in the active volume of a stereotactic diode f...

Introduction: In radiotherapy, methods of treatment planning are becoming increasingly more complicated. This requires verification of the doses delivered to increasingly smaller and more precise regions. Radiotherapy techniques are continuously employing smaller and smaller field sizes to deliver tighter radiation doses with higher therapeutic ratios, generating interest among researchers to p...

Background: Prediction of the absorbed dose in irradiated volume plays an important role in the outcome of radiotherapy. Application of small fields for radiotherapy of thorax makes the dose calculation process inaccurate due to the existence of electronic disequilibrium and intrinsic deficiencies in dose calculation algorithms. To study the lung absorbed dose in radiotherapy with smal...

A division ring of positive characteristic with countably many pure types is a field. Wedderburn showed in 1905 that finite fields are commutative. As for infinite fields, we know that superstable [1, Cherlin, Shelah] and supersimple [4, Pillay, Scanlon, Wagner] ones are commutative. In their proof, Cherlin and Shelah use the fact that a superstable field is algebraically closed. Wagner showed ...

Introduction: Small field dosimetry is challenging for radiotherapy dosimetry. measurement of the output factor in the air and water (Sc, Scp) is one of the input parameters for commissioning of treatment planning systems and beam modeling. The aims of this study are to measured Sc,Scp for small fields with EBT2 and Ion chamber and design a appropriate mini-phantom for small fi...