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..Measurements for PMMA, nylon and polystyrene sleeves of various thicknesses have also been carried out and show excellent agreement with Monte Carlo calculations...

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..To this end, measured depth ionization curves require depth-dependent correction factors...

..This means that the B factors for water may be directly used to convert the 'in-air' water kerma to surface kerma for human soft tissues...

..To demonstrate the potential of MERT for target dose coverage and normal tissue sparing for treatment of superficial targets, treatment plans for a hypothetical treatment were compared using photon beams and MERT...

..Treatment sites showing the largest dose differences were for head and neck, lung, and breast cases...

..This paper summarizes work over the past two decades on Monte Carlo simulation of clinical electron beams from medical accelerators...

..These results suggest that heterogeneity correction should be used in dose calculation for prostate cancer with non-coplanar beam arrangements...

..The differences between them were within 2%. The new algorithm was about 13 times faster than the GEANT3 Monte Carlo code for a uniform phantom geometry and over 700 times faster for a heterogeneous phantom geometry...

..Using the point-by-point method, the geometrical distortion after the GDC were reduced to <3 mm for external contour determination and the effective FOV was expanded from 36 cm to 42 cm...

..We provide practical guidelines for the clinical implementation of Monte Carlo treatment planning and show realistic examples of Monte Carlo based IMRT and MERT plans...

..It is shown that the two-layer shielding design with 10-12 cm thick polyethylene and 4 cm thick lead can effectively absorb the unwanted particles to meet the shielding requirements...

..The IMRT technique has been proven practical for breast treatment clinically. The results showed that tangential IMRT improved the dose homogeneity in the breast and reduced the dose to the lung and heart...

..The Monte Carlo calculated dose distributions were compared with measured data. Our results showed good agreement (less than 2% or 2 mm) for 6, 10 and 18 MV photon beams...

..Significant improvement in target dose uniformity and normal tissue sparing as well as in reduction of whole body dose can be achieved by IMPT with appropriate optimization and beam setup...

..We conclude that our in-house MC treatment planning system is capable of performing treatment planning and accurate dose calculations for MERT using the pMLC to deliver radiation therapy to the intact breast...

..It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost electron field...

..Knowing the dose received at the surface of the patient can lead to prediction of skin reactions helping with the design of new treatment techniques and alternative dose fractionation schemes...

..The difference in the target dose between CT- and MRI-based plans using homogeneous geometry was within 2.5%. Our results suggest that MRI-based treatment planning is suitable for radiotherapy of prostate cancer...

..It is shown that for a two-beam arrangement (parallel-opposed) it is possible to achieve both superior target coverage with 5% dose inhomogeneity within the target and excellent sparing of surrounding tissue...

..The calculations presented in this article show that the dose rate that the selection system can yield is on the order of D=260 Gy/min for a field size of 1 x 1 cm2...

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..The agreement was within 1.0%. Our results demonstrate that MCDOSE is accurate and efficient for routine dose calculation in radiotherapy treatment planning, with or without beam modifiers...

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..This preliminary study has shown the capability of the commissioning approach for handling large variation in the electron incident energy. The possibility of making the approach more versatile is also discussed...

..A homogeneous model target and a 2D breast plan are presented. The potential use of this tool in clinical planning is discussed...

..This ray tracing calculation can be applied to the problem of verifying dynamic MLC leaf sequences as part of a patient-specific quality assurance process for IMRT...

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..The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ...

..The proposed approach makes it possible to carry out a real-time comparison of the dose distribution in a transverse plane between the measurement and the reference when we do an IMRT dose verification...

..This demonstrated that for the Varian Clinac 2100C linear accelerator, electron beam dose calculations in homogeneous water phantoms can be performed accurately at the 2% level using Monte Carlo simulations...

..The algorithm is demonstrated to be applicable to both the 'step-and-shoot' and 'dynamic' type of beam delivery. The graphical interpretation and numerical implementation scheme of the algorithm is illustrated using a simplified example...

..We have implemented this method in the electron beam commissioning procedure for Monte Carlo electron beam dose calculations...

..The QA phantom has been integrated as a routine QA procedure for the patient's IMRT dose verification at Stanford since 1999...

..This technique directly translates to a decreased MSF(mod) allowing for decreased leakage dose to the patient, a decreased risk of exceeding secondary shielding limits in pre-existing vaults, and shorter treatment times...

..On the other hand, for lower alpha/beta ratios, the beta term also plays a more important role in cell-killing and therefore the patient variation parameter sigmabeta must be considered when designing a new dose fractionation scheme...

..The proposed approach is expected to be useful in removing the blurring effect on a quickly calculated Monte Carlo DVH when performing the iterative forward treatment planning...

..The impact of image noise on the performance of the algorithm has been tested. The results show that the algorithm accurately adjusts for target positional changes even with Gaussian noise levels as high as 20% inserted...

..The model will be particularly useful for IMRT dose calculations because it accurately predicts beam output and penumbra dose...

..This study aims to develop an EPID-guided 4D patient dose reconstruction framework and to investigate its feasibility for lung SBRT treatment validation...

..7 ± 4.0 cGy min⁻¹...

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..Experimental verification of the dose delivered by plans computed with the methodology demonstrated an agreement of better than 4% between the dose model and measurements...

..6% when using the SMLC delivery technique and our measured modulation scaling factors. This compares with a previously published value of 1.6% for routine 3D CRT delivery on the Varian accelerator...

..The Clarkson model overestimates the dose in lung by a maximum of 10% compared to BEAM. Dose comparisons suggest turning-off the effective path length inhomogeneity correction in the Clarkson model for lung treatments...

..The purpose of this study was to investigate the potential of MR-guided pulsed focused ultrasound (pFUS) for the enhancement of drug uptake in prostate tumors in vivo using doxorubicin (Dox)...

..5% of the Monte Carlo derived values for all the detector materials studied...

..Nonetheless, for the concern of patient care and safety, a patient specific QA should be performed as usual for IMRT plans for high dose rate deliveries...

..The impact of the number of beam angles on the relationship between V20 and the beam margin was assessed. Quantitative information about optimal beam margins for lung-cancer SBRT was obtained for clinical applications...

..It is also used for absolute dose calculations using Monte Carlo simulations for treatment verification, which has become part of our comprehensive IMRT quality assurance programme...

..These improvements were also seen in isodose curves when a complex field shape was simulated. It is thus concluded that an MLC specific for electron beam collimation is required for MERT...

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..The final dose distribution is reconstructed from the dose data at different breathing phases based on patient's breathing pattern associated with chest wall movements...

..Because of the broad energy and angular spectra of the protons, a compact particle selection and beam collimation system will be needed to generate small beams of polyenergetic protons for intensity modulated proton therapy...

..As a result, the elevated radio biological effectiveness of the proton cluster may take place and conditions for its experimental observation are presented...

..We demonstrated that it was effective to use the material's electron-density ratio to account for the dosimetric impact of the dental implant...

..The end goal is to enable the design of image guidance regimens that are as effective and efficient as possible...

..It is currently in the process of being implemented by various treatment planning vendors and will be available for clinical use in the immediate future...

..The aim of this study was to evaluate the feasibility of treating the pelvic lymphatic regions during prostate intensity-modulated radiotherapy (IMRT) with respect to our routine acceptance criteria...

..Our data showed increased (³H-docetaxel concentration in the tumor in the MRgFUS-treated group (1079 ± 132 cmp/75 mg) versus those without MRgFUS treatment (524 ± 201 cmp/75 mg) with P = 0.037...