We present self-consistent calculations of the electronic density of states of disordered copper-palladium and silver-palladium alloys using the polymorphous coherent-potential approximation and the Korringa-Kohn-Rostoker coherent-potential approximation. We find that the agreement between the theoretical partial density of states of palladium d bands in copper-rich copper-palladium alloys and experiment is significantly improved when the polymorphous coherent-potential approximation is used. The densities of states of silver-palladium alloys calculated with the two versions of the coherent-potential approximation are identical and agree with experiment. This indicates that the improved treatment of Coulomb effects in the polymorphous coherentpotential approximation is necessary only for alloys such as copper palladium that have considerable charge transfer.

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Purpose: To evaluate to treatment consistency over the total number of fractions when treatment what HDR brachytherapy using the ML cylinders. At the same time the dosimetric impact on the critical organs is monitored over the total number of fractions. Methods: A retrospective analysis of 10 patients treated with Cylinder applicators, from 2015–2016 were considered for this study. The CT scans of these patients, taken before each treatment were separately imported in to the treatment planning system and paired with the initial CT scan after completing the contouring. Two sets of CT images were fused together with respective to the applicator, using landmark registration. The doses of each plan were imported as well and a cumulative dosimetric analysis was made for bladder, bowels, and rectum and PTV. Results: No contour of any of the OAR was exactly similar when CT images were fused on each other. The PTV volumes vary from fraction to fraction. There was always a difference between the doses received by the OARs between treatments. The maximum dose varied between 5% and 30% in rectum and bladder. The minimum dose varied between 5% and 8% in rectum and bladder. The average dose varied between 15% and 20% in rectum and bladder. Deviation in placement were noticed between fractions. Conclusion: The variation in volumes of OARs and isodoses near the OARs, indicate that the estimated doses to OARs on the planning system may not be the same dose delivered to the patient in all the fractions. There are no major differences between the prescribed dose and the delivered dose over the total number of fractions. In some cases the critical organs will benefit if the consecutive plans will made after the CT scans will be registered with the initial scan and then planned.

This compendium of detailed instructions on commissioning a linear accelerator will provide good uidance to every physicist who will be involved with the installation and bringing into safe use for treatment of a new linear accelerator.

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Purpose: This study will try to find optimal procedures to collect small fields beam data for commissioning in treatment planning systems (TPS), and to provide a protocol to collect output factors for very small field sizes: 0.5 cm × 0.5 cm to 4.0 cm × 4.0 cm. This will help in determining the correct beam configuration methods in TPS planning intensity modulated radiation therapy (IMRT), and stereotactic radiosurgery SRS using mini multileaf collimation (mMLC). Methods: Data has been collected for a mMLC linear accelerator (linac) Novalis from 0.5 cm × 0.5 cm to 10 cm × 10 cm (its maximum field size). The TPS chosen is BrainLab, Eclipse & Cyberknife. The beam data collected was modeled and imported in the TPS. Verification plans were generated in solid water to confirm the goodness of the data. 3D and IMRT plans on regular CT scans were generated and verified using Mapcheck. All 3D plans with field sizes above 4 cm × 4 cm verified excellent using a distance to agreement of 2 mm and a 2% tolerance. IMRT plans gave an error of ‐8%. New scans with new detectors have been taken, new field sizes were introduced, and focus has been applied on determining the dosimetric leaf gap. Results: Although this is still a work in progress, this study brings several issues to light: the importance of the correct technique in beam data collection from the correct watertank to the correct detectors. Readings for rectangular fields have to be taken especially for fields which one side is under 4 cm. Conclusion: The use of equivalent square fields will not provide correct readings for the fields with large differences between the length and the width.

Purpose: The purpose of this study is to compare the dose‐volumetric results of intensity modulated radiation therapy (IMRT) with RapidArc (RA Varian Medical Systems, Palo Alto, CA) for whole breast irradiation. Methods: 25 whole left breast patient's plans (either RapidArc plan or IMRT) previously treated were the subjects of this study. Eclipse v 11.0.47 was used to create the alternative plans for each case using the same CT images, contours, energy, Linac and normalization. The prescription dose to the planning target volume was 50 Gy in 25 fractions. All plans were normalized such that 100% of the dose covered 95% of planning target volume (PTV). Results: V10, V20 and Dmean Gy of left lung differ significantly between the two plans (p‐value <0.0001, =0.0473 and <0.0001 respectively). However, V30 Gy does not (p‐value 0.463). V25, D33 and Dmean Gy of heart differ significantly between the two plans (p‐value =0.034, <0.0001 and 0.01 respectively). However V10 Gy does not (p‐value 0.058). V5 of both right breast and right lung differs significantly between the two plans (p‐value <0.0007 and =0.0112, respectively). Dmean of both right breast and right lung differs significantly between the two plans (p‐value <0.0001 for both). The mean conformity index did not differ significantly, p‐value 0.142. There was a significant difference between the mean MUs of the two plans as well, p‐value <0.0001. Conclusion: Mean doses to left lung, heart, right lung and right breast were significantly different in RapidArc than IMRT plans. IMRT treatment delivery was faster than RapidArc in terms of the total monitor units used (mean of 382 vs 707 respectively). In fact, since it was observed that both plans have the same mean of conformity index, IMRT is not only faster but also safer regarding not irradiating the organs at risk.