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PURPOSE: High dose rate (HDR) brachytherapy is a treatment method that is used increasingly worldwide. The development of a sound quality assurance program for the verification of treatment deliveries can be challenging due to the high source activity utilized and the need for precise measurements of dwell positions and times. This paper describes the application of a novel phantom, based on a 2D 11 × 11 diode array detection system, named "magic phantom" (MPh), to accurately measure plan dwell positions and times, compare them directly to the treatment plan, determine errors in treatment delivery, and calculate absorbed dose. METHODS: The magic phantom system was CT scanned and a 20 catheter plan was generated to simulate a nonspecific treatment scenario. This plan was delivered to the MPh and, using a custom developed software suite, the dwell positions and times were measured and compared to the plan. The original plan was also modified, with changes not disclosed to the primary authors, and measured again using the device and software to determine the modifications. A new metric, the "position-time gamma index," was developed to quantify the quality of a treatment delivery when compared to the treatment plan. The MPh was evaluated to determine the minimum measurable dwell time and step size. The incorporation of the TG-43U1 formalism directly into the software allows for dose calculations to be made based on the measured plan. The estimated dose distributions calculated by the software were compared to the treatment plan and to calibrated EBT3 film, using the 2D gamma analysis method. RESULTS: For the original plan, the magic phantom system was capable of measuring all dwell points and dwell times and the majority were found to be within 0.93 mm and 0.25 s, respectively, from the plan. By measuring the altered plan and comparing it to the unmodified treatment plan, the use of the position-time gamma index showed that all modifications made could be readily detected. The MPh was able to measure dwell times down to 0.067 ± 0.001 s and planned dwell positions separated by 1 mm. The dose calculation carried out by the MPh software was found to be in agreement with values calculated by the treatment planning system within 0.75%. Using the 2D gamma index, the dose map of the MPh plane and measured EBT3 were found to have a pass rate of over 95% when compared to the original plan. CONCLUSIONS: The application of this magic phantom quality assurance system to HDR brachytherapy has demonstrated promising ability to perform the verification of treatment plans, based upon the measured dwell positions and times. The introduction of the quantitative position-time gamma index allows for direct comparison of measured parameters against the plan and could be used prior to patient treatment to ensure accurate delivery.

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Some treatment planning system can divide a treatment plan calculation into multiple threads and allow both local and network computing resources to perform the calculation concurrently, which significantly reduces the calculation time for a calculation-demanding planning such as Volumetric Modulated Arc Therapy (VMAT) or electron Monte Carlo (eMC). This study tested in Eclipse (Varian, V10.0.39) the impact of Distributed Calculation Framework (DCF, V10.0.0.757) settings on calculation time in a planning environment that consists of 20 workstations with 8 core processors and 16GB RAMs installed on most of them. It is found that for an arc plan increasing the control point field parallelization factor reduces the total calculation time at beginning but lengthens the total calculation time after a certain level as a result of data sending time increase. Further increasing the factor may cause a serious net work traffic or even failure of a calculation. For an eMC plan the calculation time decreases monotonously with the increase of Monte carlo field parallelization factor, and the data sending time is insignificant compared to the calculation time. Increasing the local servant numbers reduces the data sending time but raises the calculation time for arc and eMC plans. The calculation time increment is more and more significant with the increase of local servants. The optimal DCF setting for a facility depends on the total number of calculation workstations available, the hardware configuration of the workstations, and the data transfer rate of the network. No conflict of interest exists in the study.

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PURPOSE: PARETO (Pareto-Aware Radiotherapy Evolutionary Treatment Optimization) is a novel multiobjective treatment planning system that performs beam orientation and fluence optimization simultaneously using an advanced evolutionary algorithm. In order to reduce the number of parameters involved in this enormous search space, we present several methods for modeling the beam fluence. The parameterizations are compared using innovative tools that evaluate fluence complexity, solution quality, and run efficiency. METHODS: A PARETO run is performed using the basic weight (BW), linear gradient (LG), cosine transform (CT), beam group (BG), and isodose-projection (IP) methods for applying fluence modulation over the projection of the Planning Target Volume in the beam's-eye-view plane. The solutions of each run are non-dominated with respect to other trial solutions encountered during the run. However, to compare the solution quality of independent runs, each run competes against every other run in a round robin fashion. Score is assigned based on the fraction of solutions that survive when a tournament selection operator is applied to the solutions of the two competitors. To compare fluence complexity, a modulation index, fractal dimension, and image gradient entropy are calculated for the fluence maps of each optimal plan. RESULTS: We have found that the LG method results in superior solution quality for a spine phantom, lung patient, and cauda equina patient. The BG method produces solutions with the highest degree of fluence complexity. Most methods result in comparable run times. CONCLUSION: The LG method produces superior solution quality using a moderate degree of fluence modulation.

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Stereotactic body radiation therapy (SBRT) requires precise delivery of radiation to the target; intra- and inter-fraction lung tumour motion may adversely impact local tumour control. The purpose of this study was to retrospectively evaluate the impact of planning target volume (PTV) margin size on the coverage of the internal target volume (ITV) as localized in pre- and post-treatment cone-beam computed tomography (CBCT) images. Data from two patients undergoing SBRT were evaluated. For planning, free-breathing and 4DCT scans were performed, and used to contour the ITV. A 5mm margin was added to create the PTV. During treatment, 14 CBCTs were collected pre- and post-beam delivery. A data set comprising the average 4DCT intensities where available and treatment planning CT intensities for voxels that were beyond the field of view of the 4DCT was constructed. Registration of the combined planning image to each CBCT was performed using a deformable image registration algorithm. The transformations aligning the combined planning image with the CBCTs were applied to the planning ITV to obtain the treatment ITVs. For each CBCT, the fraction of treatment ITV within the PTV was determined using Boolean logic. This was repeated for various PTV margins ranging from 0 to 10 mm at 1mm intervals. The 3 and 5 mm PTV margins covered 95.1 ± 5.9% and 99.0 ± 2.0% of the ITV, respectively. Analysis of additional patients will be performed to confirm these preliminary results, which reinforce the use of a 5mm PTV margin for lung SBRT.

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PURPOSE: To use Control Point Analysis (Sun Nuclear Corporation, Melbourne, Florida, USA) to analyze and compare delivered VMAT plans for three different treatment planning complexity levels. METHODS: Nineteen patients were chosen and fully anonymized for the purpose of this study. Ten SBRT, six H&N, one breast and two prostate VMAT plans were generated on Pinnacle3 and delivered on a Varian LINAC. The delivered dose was measured using ArcCHECK™. Each plan was analyzed using SNC Patient 6 and Control Point Analysis. Gamma passing percentage was used to assess the differences between the measured and planned dose distributions and to assess the role of various control point binning scenarios. RESULTS: The prostate cases reported the highest gamma passing percentages for SNC Patient 6 (99.3%-99.5%,3%/3mm) and Control Point Analysis (99.1--99.3%,3%/3mm). The mean percentage of passing control point sectors for the prostate cases increased from 48.9±3.1% for individual control points to 69.5 ± 3.9% for 5 control points binned together to 100±0% for 10 control points binned together. Over all, there was a trend in the percentage of sectors passing gamma analysis increasing with the increase of the number of control points binned together in one sector for both passing criteria considered (48.9±3.1% for individual control points to 69.5±3.9% for 5 control points binned together in one sector to 100±0% for 10 control points binned together in one sector for the prostate). CONCLUSION: The delivery accuracy per control point depends on the MU/control point (SBRT) and the plan degree of modulation (H&N).

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The measurement of output factors for small fields is challenging and can lead to large dose errors in patient treatments if corrections for detector size and scatter from high-Z material are not applied. Due to its high spatial resolution and near tissue equivalence, GAFCHROMIC® film potentially provides a correction free measure of output factors but it can be challenging to obtain high quality dosimetric results using this film. We propose minimizing errors in the clinical determination of small field output factors by employing diode measurements with Monte-Carlo generated corrections for small fields ≤10 mm diameter and using small volume ion chambers for apertures >10 mm diameter with independent validation using radiochromic film. We performed patient specific quality assurance (QA) measurements for 9 patients using GAFCHROMIC® film and an A16 small volume ion chamber in a head-shaped phantom, employing this hybrid dual detector method for relative output factor measurements within the Multiplan treatment planning system. Our results suggest that consistent output factors can be determined using this method with experimental verification using GAFCHROMIC® film dosimetry. For the patient specific QA using film, we achieve good dosimetric agreement (<2σ) of the measured and calculated average dose for pixels within the 80% isodose line. For patient specific QA using the micro-ion chamber, we get good agreement (<3%) for cone sizes greater than 5 mm. The differences observed for the 5 mm cone plans are consistent with a 1 mm radial setup uncertainty for patient positioning using the Cyberknife system.

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In early stage prostate cancer, low dose rate (LDR) prostate brachytherapy is a favorable treatment modality, where small radioactive seeds are permanently implanted throughout the prostate. Treatment centres currently rely on a commercial optimization algorithm, IPSA, to generate seed distributions for treatment plans. However, commercial software does not allow the user access to the source code, thus reducing the flexibility for treatment planning and impeding any implementation of new and, perhaps, improved clinical techniques. An open source genetic algorithm (GA) has been encoded in MATLAB to generate seed distributions for a simplified prostate and urethra model. To assess the quality of the seed distributions created by the GA, both the GA and IPSA were used to generate seed distributions for two clinically relevant scenarios and the quality of the GA distributions relative to IPSA distributions and clinically accepted standards for seed distributions was investigated. The first clinically relevant scenario involved generating seed distributions for three different prostate volumes (19.2 cc, 32.4 cc, and 54.7 cc). The second scenario involved generating distributions for three separate seed activities (0.397 mCi, 0.455 mCi, and 0.5 mCi). Both GA and IPSA met the clinically accepted criteria for the two scenarios, where distributions produced by the GA were comparable to IPSA in terms of full coverage of the prostate by the prescribed dose, and minimized dose to the urethra, which passed straight through the prostate. Further, the GA offered improved reduction of high dose regions (i.e hot spots) within the planned target volume.

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In a previous study, the variogram fractal dimension (FD) method was found to be very accurate at identifying planned head and neck IMRT fields that are overly-modulated. In the current study, the authors used MATLAB® to develop FracMod, a graphical user interface (GUI) and variogram FD analysis tool to assess modulation complexity of dynamic IMRT fields designed for treatments of the prostate alone and prostate plus pelvic nodes. A set of 5 prostate plans (25 fields) and 5 prostate plus pelvic node plans (35 fields) were used to choose FD cut-points that ensure no false positives (100% specificity) in distinguishing between moderate field modulation (typical modulation used clinically at the authors' institution) and high modulation. Field modulation was controlled by adjusting fluence smoothing parameters in the Eclipse™ treatment planning system. The area under the curve (AUC) from receiver operating characteristic (ROC) analysis was used to quantitatively compare the ability of FD and the number of monitor units (MUs) for distinguishing between the moderate and high modulation fields. The variogram FD method gave AUCs of 0.96 (almost perfect classification) and 1.00 (perfect classification) for the prostate alone and the prostate plus pelvic node fields, respectively. The variogram FD method is an accurate metric; performing better than the number of MUs at identifying high modulation IMRT fields planned for the treatment of prostatic carcinoma. Hence, FracMod will enable Radiotherapy Physicists to easily and accurately quantify the degree of modulation of IMRT fields and adjust overly-modulated fields at the treatment planning stage.

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The aim of this study is to validate the electron Monte Carlo module implemented in XiO, a treatment planning system commercialized by Elekta CMS inc. Two types of phantoms were investigated: homogeneous water phantoms with irregular surfaces and phantoms containing slab and 3D heterogeneities. The phantoms were CT scanned, and dose to water calculations were performed in the eMC module using 2 ×2 × 2 mm2 voxels and a mean relative statistical uncertainty of 0.5%. Concurrently, Gafchromic EBT3 film measurements were performed in the same phantoms. To obtain reliable absolute dose readings from the films, a new method using triple channel dosimetry in the Film QA Pro software was developed. The accuracy of the proposed method was determined empirically and an uncertainty of ±1.5% was found over the range [75, 800] cGy. Dose comparisons between film and simulations were done using an in-house MATLAB program. XiO's eMC module provides accurate dose distributions in the presence of surface irregularities and slab heterogeneities for 12 MeV beams. In the presence of 3D heterogeneities, the percent dose difference comparisons highlighted the need to perform 3D gamma comparisons. In conclusion, the electron Monte Carlo module offered in the XiO treatment planning system is promising and could greatly improve the accuracy of clinical dose calculations. The validation of the software is ongoing, notably concerning more complex phantom geometries. Small field calculations, oblique incidences and cutout factors will also be investigated.

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Modulated electron radiotherapy (MERT) takes advantage of the low distal dose of electrons to reduce dose to healthy tissue. The dosimetric advantage of MERT is clear when compared against single-field electron irradiation where MERT demonstrates superior target homogeneity and sparing; however the dosimetric advantage is unclear when comparing MERT with photon intensity-modulated radiotherapy (IMRT) where MERT techniques struggle to match the IMRT target homogeneity but with less total energy delivered to healthy tissues. In an effort to improve dosimetric benefits of MERT, this study investigated an inverse planning technique for the creation of hybrid MERT-IMRT mixed beam radiotherapy (MBRT) plans. The optimization process decouples the photon and electron beamlets for combined modality optimization. The input to the optimization algorithm was a series of patient-specific 3D dose distributions for the corresponding electron and photon beamlets, while the output was a list of weights that satisfied the optimization constraints. A photon IMRT Eclipse (Varian, Palo Alto, CA) plan and a MERT plan were created for a patient-specific sarcoma irradiation. The MERT plan was competitive in its ability to reduce dose to organs at risk and total-body dose; however, the plan suffered from poorer target conformity compared with the IMRT plan. The MBRT plan was created by adding two photon fields, divided into beamlets, to the electron beamlets of the MERT plan for reoptimization. The MBRT plan improved MERT target coverage with only minimal cost to healthy tissue dose. The MBRT plan provided clear dosimetric advantages over the IMRT and MERT plan.

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Stereotactic Body Radiation Therapy (SBRT) is an option for early stage non-small cell lung cancer treatment. In SBRT treatment, high biological effective dose is delivered to the patient within a small number of fractions. High level of confidence in accuracy is required in the entire treatment procedure, from patient setup, tumour delineation, treatment simulation and planning, to the final dose delivery. SBRT lung treatment utilizes small fields that are incident on large tissue inhomogeneities within the patient. It is difficult for commercially available treatment planning systems (TPS) to model the lack of charged particle equilibrium and the dose near tissue-lung interfaces accurately. The Monte Carlo (MC) technique calculates the dose distribution from the first principles thereby providing a feasible tool for verifying the dose distribution computed from TPS. In this study, we compared the SBRT dose distribution between Eclipse 8.9 and BEAMnrc/DOSXYZnrc for both conformal and RapidArc plans. Calculation results for five clinical SBRT conformal lung plans were compared. Eclipse and MC results for each plan showed good agreement in dose received by organs at risk. MC simulation predicted uniformly hotter or similar PTV coverage for three cases with tumor either small or attached to the chest wall. When tumor is inside lung and at relatively medium to larger size for SBRT, MC predicted lower PTV coverage. The variation in dose coverage may depend on the tumour size and its position within the lung. Dose comparison for RapidArc plans shows similar dependence.

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Innovation/Impact: We describe the web-based QA infrastructure under development and in use within our paperless radiation oncology clinic. Our framework comprises a centralized web-server that facilitates simultaneous and seamless access to multiple databases within the clinic. All activities, including treatment planning, patient appointments and machine quality control/maintenance, are accessible via a single internal webpage with various software tools and metrics employed for QA and monitoring. We believe that our framework is representative of the direction in which modern radiation oncology departments are moving; namely paperless operation with centralized data access for patient-specific QA and statistical process control.

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DICOM format is the de facto standard for communications between therapeutic and diagnostic modalities. A plan generated by a treatment planning system (TPS) is often exported to DICOM format. BEAMnrc/DOSXYZnrc is a widely used Monte Carlo (MC) package for beam and dose simulations in radiotherapy. It has its own definition for beam orientation, which is not in compliance with the one defined in DICOM standard. Dose simulations using TPS generated plans require transformation of beam orientations to DOSXYZnrc coordinate system (c.s.) after extracting the necessary parameters from DICOM RP files. The transformation is nontrivial. There have been two studies for the coordinate transformations. The transformation equation sets derived have been helpful to BEAMnrc/DOSXYZnrc users. However, both the transformation equation sets are complex mathematically and not easy to program. In this study, we derive a new set of transformation equations, which are more compact, better understandable, and easier for computational implementation. The derivation of polar angle θ and azimuthal angle φ is similar to the existing studies by applying a series of rotations to a vector in DICOM patient c.s. The derivation of beam rotation Φcol for DOSXYZnrc, however, is different. It is obtained by a direct combination of the actual collimator rotation with the projection of the couch rotation to the collimator rotating plane. Verification of the transformation has been performed using clinical plans created with Eclipse. The comparison between Eclipse and MC results show exact geometrical agreement for field placements, together with good agreement in dose distributions.

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PURPOSE: To present an institutional experience with MRI-based intracavitary brachytherapy planning for cervix cancer treatments using the EMBRACE protocol and to evaluate maximum HR-CTV doses that can be achieved when OAR (bladder, rectum, and sigmoid) doses are allowed to equal GECESTRO recommended thresholds. METHOD: Dose metrics from treatment plans for 20 patients created using MR images (for contouring HR-CTV and OARs) fused with CT images (for applicator reconstruction) are presented. Starting with a standard Manchester loading, plans were manually optimized (MO) by adjusting dwell positions and times to obtain the desired HR-CTV D90 target coverage of 35 Gy while limiting OAR doses to below recommended tolerances. In addition, retrospective planning was done using: (i) volume optimization (VO) to compare differences with MO in obtaining the desired target coverage; and (ii) MO and VO techniques to get the highest possible HR-CTV coverage by allowing OAR doses to equal tolerance values. The latter plans are referred to as MAX plans. RESULTS AND CONCLUSIONS: 3D MRI-guided treatment planning for cervix brachytherapy was shown to improve dose-volume coverage of the target and OARs. MO could conform HR-CTV D90 to the prescribed dose similar to the VO technique. Sigmoid was often the dose limiting structure. With respect to the prescribed HR-CTV D90 dose of 35 Gy, MAX plans could increase the prescribed dose by about 22% and 30% for MO and VO plans, respectively, without exceeding OAR thresholds. Consequently, dose escalation for MRI-guided cervix brachytherapy appears feasible should clinical circumstances warrant.

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The treatment planning software SharePlan is designed to convert dose distributions generated by the TomoTherapy planning station into step-and-shoot IMRT plans deliverable on a c-arm linear accelerator. Five anal canal patients who were planned for TomoTherapy treatments were exported into a SharePlan system and plans were generated for delivery on an Elekta Synergy unit. A total of 80 plans were generated for those five patients, with either seven, nine, eleven or twenty-one gantry angles and different priorities between focusing on matching either the target doses or healthy tissue sparing of the TomoTherapy plan. The plans generated by SharePlan, while often not matching target coverage at prescription, matched well the TomoTherapy coverage at 95% and 105% of the prescription dose. Organ at risk dose, when heavily emphazied in the SharePlan calculations matched or bettered the TomoTherapy dose due to the placement of the beams and the sharper sup-inf fall off of the dose distribution on a linac. For one of the patients, it was possible to produce a better DVH with SharePlan than the original TomoTherapy plan for those reasons. The TomoTherapy plans boasted significantly shorter delivery times than the plans generated with SharePlan.

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125 I brachytherapy used in conjunction with sublobar resection to treat stage I non-small cell lung cancer has been reported to improve disease-free and overall survival rates compared with resection alone. Treatments are planned intra-operatively using seed spacing nomograms or tables to achieve a prescription dose defined 5 mm above the implant plane. Dose distributions for patients treated with this technique at the Mayo Clinic Rochester were reanalyzed using a Monte Carlo (MC) calculation; significant differences were observed between the standard TG-43 dose calculations and the actual dose delivered as determined by MC. This work investigates differences between TG-43 calculated prescription doses and those calculated in more accurate models. Monte Carlo calculations are performed using the EGSnrc user-code BrachyDose with a number of lung tissue phantom models including patient CT-derived phantoms. Seed spacing nomograms using these models are recalculated by determining the dose to the prescription point using the activities per seed required to produce a prescription dose of 100 Gy with the TG-43 point source formalism. Models using nominal density lung or CT-derived density lung tissue result in a significant increase in dose to the prescription point (up to approximately 25%) compared to TG-43 calculated doses. The differences observed suggest that patients routinely receive significantly higher doses than planned using TG-43 derived nomograms. Additionally, deviation from TG-43 increases as seed spacing increases. Media heterogeneities significantly affect dose distributions and prescription doses for 125 I lung brachytherapy, underlining the importance of using model-based dose calculation algorithms to plan and analyze these treatments.

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PURPOSE: The aim of this study was to evaluate and analytically compare different calculation algorithms applied in our country radiotherapy centers base on the methodology developed by IAEA for treatment planning systems (TPS) commissioning (IAEA TEC-DOC 1583). MATERIAL & METHODS: Thorax anthropomorphic phantom (002LFC CIRS inc.), was used to measure 7 tests that simulate the whole chain of external beam TPS. The dose were measured with ion chambers and the deviation between measured and TPS calculated dose was reported. This methodology, which employs the same phantom and the same setup test cases, was tested in 4 different hospitals which were using 5 different algorithms/ inhomogeneity correction methods implemented in different TPS. The algorithms in this study were divided into two groups including correction based and model based algorithms. RESULTS: A total of 84 clinical test case datasets for different energies and calculation algorithms were produced, which amounts of differences in inhomogeneity points with low density (lung) and high density (bone) was decreased meaningfully with advanced algorithms. The number of deviations outside agreement criteria was increased with the beam energy and decreased with advancement of the TPS calculation algorithm. CONCLUSION: Large deviations were seen in some correction based algorithms, so sophisticated algorithms, would be preferred in clinical practices, especially for calculation in inhomogeneous media. Use of model based algorithms with lateral transport calculation, is recommended. Some systematic errors which were revealed during this study, is showing necessity of performing periodic audits on TPS in radiotherapy centers.

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When performed daily, cone beam CT (CBCT) images can accumulate radiation dose to non-negligible levels. Because kV x-rays have a larger relative biological effectiveness (RBE) than its MV x-rays, the accumulated absorbed dose needs to be multiplied by an appropriate RBE to better evaluate the impact of CBCT dose in a treatment planning context. We investigated this question using PENLEOPE simulations to look in detail at the electron energy spectra produced by kV x-rays and Co-60 γ-rays in biologically motivated geometries. The electron spectra were input into the published Monte Carlo Damage Simulation (MCDS) and used to estimate the average number of double strand breaks (DSBs) per Gy per cell. Our results suggest an approximately 10% increase in the RBE for DSB induction. For the majority of treatment planning scenarios where imaging dose is only a small fraction of the total delivered dose to target volumes and organs at risk, the increase in RBE is not critical to be factored in, however for it may play a significant role in predicting the induction of secondary cancers.

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The most recent reviews of accuracy requirements in radiation oncology were published in the 1990s, primarily in an era that was transitioning from 2-D to 3-D conformal radiation therapy (CRT). Since then, the technology associated with radiation oncology has changed dramatically. The combination of various forms of imaging for radiation therapy planning, treatment planning software, dose delivery technology including 4-D considerations as well as in-room daily image guidance has resulted in new perspectives on accuracy considerations. The underlying hypothesis for the use of these advanced technologies is that loco-regional control of cancer remains a significant barrier to cancer cure for many common cancers and that better dose distributions will translate into better outcomes. However, further clinical gain using these new technologies may be limited by single or compounded uncertainties associated with the entire treatment process. Thus, it is important to understand what factors should be considered in determining accuracy requirements as well as the realistic expectations of uncertainties that exist within the total treatment process. The need for accuracy is based on clinical requirements such as the steepness of dose-response curves, inherent heterogeneity in patient response to treatment, and the level of accuracy that is practically achievable. Statements on accuracy are dependent on the technology used and the reality of what is practically achievable and necessary. This review highlights some of the major differences between accuracy requirements as determined in the 2-D RT and 3-D CRT era versus the modern era of intensity modulated, image-guided, 4-D radiation therapy.

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A set of tests were designed to verify an electron algorithm effectively and quickly during a treatment planning system upgrade. Based on TG-53 report's suggestion and the assumption that the algorithm is well commissioned before the upgrade, the tests spot-check the output factors, depth doses, off-axis doses and treatment field sizes. The field sizes of 4×4, 6×6, 10×10, 15×15, 20×20 and 25×25 are to be tested. Four test plans are created for each field size, i.e., for open field, for extended SSD, for shaped field, and for bolus field. Fixed MU setting is recommended to avoid a possible plan normalization issue. The parameters to be recorded and compared include doses at dmax , R50 and Rp along central axis, which contain output and depth dose information, doses at four off-axis points in dmax plane, which contain off-axis dose and beam symmetry information, and FWHMs at dmax . For the plans other than open field only doses at dmax are checked. The tests were performed successfully during a planning system upgrade. The whole test can be completed in approximately 12 hours if the workload is distributed into multiple task carriers. It was found that most of the data agree very well between the old and the new version of the algorithm while some of the Rp or R50 doses deviated more than other data, which prompted a depth dose check. PDD comparisons were performed for the involved fields and it was found there were less than 0.5 mm PDD shifts occurred.