Treatment techniques

During hypofractionation higher doses are delivered to the target within a treatment, than during normal radiation therapy. Accuracy of these treatments are therefore essential. RadCalc’s 3D Monte Carlo module employs the most established Monte Carlo dose engine available (BEAMnrc) and also utilizes proprietary machine modelling acquired from McGill University. Dose volumes verified with RadCalc thus increase patient safety and plan quality by enhancing your ability to more accurately verify complicated treatment plans. Studies have shown the verification dose to be within ± 3 % of the treatment plan dose providing very high accuracy.

Radiation therapy continues to grow in complexity, consequently the task of Quality Assurance has become more time consuming. RadCalc was developed by a ABR board certified physicist to make the task of performing independent dosimetric validation calculations much faster, easier and more accurate. RadCalc’s dosimetric calculations provide a fully automated process for your QA routine which can be seamlessly integrated into adaptive radiation therapy workflows.

RadCalc provides Monte Carlo and Collapsed Cone Convolution Superposition based algorithm modules that deliver fast, easy, and accurate 3D Dose Volume verification. Utilizing a patient’s planning CT for calculations, RadCalc’s 3D functionality offers verification for 3D, IMRT, VMAT, and SRS/SBRT plans. Dose throughout the treatment volume is verified with RadCalc thus increasing patient safety and plan quality by enhancing your ability to more accurately verify complicated SRT/SBRT treatment plans.

RadCalc’s 3D functionality includes RadCalcAIR (Automated Import & Reporting) providing a fully automated process with Percent difference, DVH, Gamma, Distance to Agreement analysis tools. RadCalc’s automated process alerts you to plans that fail to pass your pre-set Gamma Analysis acceptance criteria. Additionally, RadCalc automatically checks whether DVH objectives are met for critical structures using both the TPS and RadCalc’s 3D dose.

RadCalc performs independent MU or point dose calculation for step-and -shoot and sliding window IMRT treatment plans. The IMRT computation is performed utilizing a modified Clarkson scatter integration along with a head scatter algorithm to improve accuracy.

The algorithm utilized by RadCalc was published in an article in the October 2000 issue of the Medical Physics Journal. Since publication of this article, the algorithm utilized has been updated to further improve accuracy. The MLC leaf sequence patterns can be imported into RadCalc through various mechanisms. The MLC patterns can be changed and exported to a R&V system.

A regions of interest module is part of RadCalc's photon calculations for performing second check calculations for VMAT. ROI structures are exported with the plan file from the VMAT calculation to the RadCalc software. Average densities for the various structures can be either imported or manually entered. RadCalc computes an independent depth and effective depth value for each individual control point as well as the dose comparison for all imported calculation points. Additionally, an average depth and effective depth are determined. Users can also utilize the Volume Average Dose Tool to analyze the variation in dose (at a given distance) around the primary calculation point. This tool is very effective for analysing the dose distribution when the calculation point is in a high dose gradient or the planning system is using a large dose grid.

RadCalc follows the TG-43 protocol to perform 3D dose volume and point dose verification for HDR (incl. Xoft), LDR and for Permanent Implant treatments. The TPS and RadCalc dose can be compared side by side in either 2D or 3D views. Isodose levels can be displayed, Dose Volume analysis can be performed using Percent Difference DTA or Gamma analysis and DVH protocols can be used. RadCalc can compute the dose and DVH based on translated and/or rotated sources for an individual treatment. Comparing the isodoses, DVH with the optimal source position the clinical impact of a source mislocation can be evaluated.

Prior to actual patient treatment users of RadCalc can perform independent MU and dose calculation of individual points or 3D volumes. The pre-treatment verification activities can be extended with Fluence and Dose Map image analysis. RadCalc’s calculated Dose Map can be compared with a measured Dose Map. Additionally, calculated fluence can be compared with TPS fluence or the calculated fluence from the linac log files. These pre-treatment checks can be performed with data from RadCalc Dose, Pinnacle Dose, Dicom Dose, DICOM Image, Pinnacle ODM, RadCalc Fluence, imported Fluence, MapCHECK dose map or IBA MatriXX dose map.

Treatment delivery data acquired during the treatment can be used for machine performance analysis. The intended plan can be compared to the delivery reconstructed from Dynalog or TrajectoryLog files, as well as RadCalc LINAC Log created from iCom data transfer for Elekta LINACs. The available analysis methods allow the calculation of the percentage dose difference, distance to agreement value and the gamma values. The statistical results are shown on a histogram, and the comparison results can be visualised along any arbitrary line in a 2D plane or as a 3D dose volume analysis.
 

RadCalc can perform in-vivo diode or TLD calculations for photon and electron beams by computing an expected reading or range, based on the Dmax dose. Correction factors for photon beams may include: SSD, field size, attenuation factors, wedge factors and off-axis factors. Cone correction factors may be used for electron beams. In-vivo verification results can be collected through the whole course of treatments and can be stored together with the secondary dose verification calculations. By exporting the results to the R&V System it can be part of the complete patient documentation in one system.