Report No.34 from SFPM: QualiFormeD helps you!

Report No. 34 from the French Society of Medical Physics (SFPM) "Quality Assurance in Rotational Intensity Modulation Radiation Therapy (VMAT)" was released last November.

This report shows issues for which the software solutions developed by QUALIFORMED bring many solutions:

• QUALIMAGIQ^CE software platform for automatic analysis of Quality Control (QC) measurements carried out as part of the QC of radiotherapy and medical imaging devices;
• LINACWATCH^{CE & FDA510k} software for continuous and real-time QC of Linacs performance through the analysis of the log files generated;
• And last QUALINAX, software platform for complete and paperless management of QC and maintenance tasks on radiotherapy and medical imaging devices.

QUALIMAGIQ proposes ISO modules that, in addition to providing the position and size of all radiation isocenters of the device using the "Winston & Lutz" test extended to on-board imaging, with the same images as those acquired for this test and a method patented by QUALIFORMED, enables accurate measurement of the gantry collimator and the treatment couch angles. Moreover, QUALIMAGIQ measures the radiative angles rather than the mechanical angles; reflecting the actual reality of the treatment.

QUALIMAGIQ also of course proposes a MLC-dyn module dedicated, to the CQ of Multi-leaf Collimator (MLC) used to modulate beam intensity with or without simultaneous gantry rotation. This module supports "Picket Fence" tests with static and rotating gantry, with and without intended errors, the "Sliding windows" test, the test of leaf speed and dose rate gating, of the arc length and/or gantry speed and dose rate gating, and finally the "Snooker cue" test developed by Ann VAN ESCH. This is the only solution on the market that eliminates portal imager sagging and gantry flex during these tests, by applying a unique method. Then this is the only solution on the market that will enable you to set relevant tolerances on your "Picket Fence" tests, ie from 0.2 to 0.6 mm on the position and on the width of the "Picket slits". Without taking these two artifacts into consideration, the tests consist more in measuring portal imager sagging and gantry flex than in truly evaluating MLC performance because the intensities of these movement artifacts are at a least 0.5 mm, more than twice the minimum tolerance on MLC tests. Replacing the films with the portal imager to perform these tests is much more convenient, but it is essential, in this case to overcome artifacts of movement of the portal imager relative to the radiation source.

QUALIMAGIQ offers the TOMOT module dedicated to TOMOTHERAPY^® devices. This module automatically checks the quality of the images originating from the device thanks to 2 dedicated inserts that are positioned in the "Cheese" phantom. This is largely incomplete relative to the QCs to be performed on this type of device however QUALIFORMED is of course highly motivated to develop partnerships to increase its range of automated QC on TOMOTHERAPY devices.

Although the SFPM report does not deal with CYBERKNIFE^® devices that are classified as radiosurgery devices, it is important to note that QUALIMAGIQ also has many solutions to automate QC performance and analysis for this type of installation:

• A high-energy portable imager (CK-IMAGER) to acquire QC images of all collimation systems (cones, iris and MLC);
• A module CK-PILOT which operates the image acquisition with the CK-IMAGER;
• Two modules for automatic analysis of these images, CK-COLLI and CK-MLC;
• A module EPID-KV+ which automatically analyses the QC images done to evaluate performances of the two KV imagers integrated on the device;
• A DOSE-R module for automatic analysis of the profiles and the depth dose curves carried out with a water tank scanning system and/or a matrix of detectors.

LINACWATCH checks continuously and in real-time that every single beam delivered on the Linac complies with the medical prescription.

Before the pre-treatment QA: LINACWATCH checks if a treatment is compliant with its class (notion introduced in § III.2.1 p 94 of the SFPM report) by calculation of the MCS ("Modulation Complexity Score") which highlights the treatment complexity and therefore the ability of the treatment device to achieve it. This control consists in verifying that the prescription RTplan file matches with what is usually prescribed for this class. LINACWATCH introduced this notion of treatment class 2 years ago. LINACWATCH also tests the number of Control Points included in the RTplan file, and the maximum number of Monitor Units.

During Pre-treatment QA: This SFPM report describes the difficulties encountered in performing pre-treatment QAs with traditional methods using a phantom or portal imager. By using LINACWATCH as well, starting with the pre-treatment QA, we can pinpoint failures that lead to incorrect pre-treatment QAs. In addition, using LINACWATCH from the start of pre-treatment QA, the correct transfer of dosimetry information to the Linac is analysed.

During treatments: LINACWATCH is basically the ideal complement to pre-treatment QA because it is a continuous and autonomous Linac QC system that is fully integrated into patient workflow with relevant sensitivity and exceptional accuracy. LINACWATCH operates continuously (and running in the background) with no human intervention. It warns you by audible alarms and/or emails if the tolerances you have set by treatment class are exceeded. Thus you have the IGRT which ensures the automatic repositioning of the patient at each session, restraining systems that immobilize the patient during treatment and finally LINACWATCH which effortlessly checks that the beam was properly delivered. If the patient is OK and the beam is OK, the treatment is necessarily OK.

QUALINAX is a complete and paperless management solution for ALL Quality Control (QC) and maintenance tasks. Fulfilling its several functions, it is:

• A solution that can support any type of QC including "in-house" QCs that you perform with MS-Excel spreadsheets;
• A database that centralizes all your QC measurements and associated analyses, analyses performed by QUALIMAGIQ or any other competitor’s solution;
• Software that assists you with each QC task by providing you with all the multimedia documentation describing each QC steps;
• Software that plans all your QCs and verifies that they are performed in accordance with the planned schedule.

In maintenance, it is a computerised notebook including all the maintenance tasks and tracing in 1 click the solutions that you had already implemented to solve a breakdown. Since November 2018 QUALINAX not only manages Linacs but also manages all types of devices, for example an MRI, scanner, TPS, brachytherapy device...

Since we have concentrated on only this for the past 14 years, QUALIFORMED has gained solid expertise in Quality Control in Radiotherapy and Medical Imaging which it offers up to its customers, who do not have only QC software to think about all day long!