The dosimetry specialist PTW Freiburg GmbH signed a collaboration agreement with The Netherlands Cancer Institute – Antoni van Leeuwenhoek Hospital (NKI-AVL, Amsterdam) to jointly develop an advanced EPID-based dosimetry solution for automated patient-specific quality assurance in radiotherapy. The new software module RT EPID, which will become part of PTW’s patient QA platform VERIQA, builds on the well-established back-projection algorithm of NKI-AVL for EPID-based 3D pre-treatment and in vivo dose verification.
As part of PTW’s VERIQA patient QA platform, VERIQA RT EPID will provide a fully automated, streamlined verification workflow – from measurement and analysis to approval and documentation.
The new VERIQA module will use the advanced back-projection method of NKI-AVL for dose reconstruction, offering significant clinical advantages. Unlike most EPID dosimetry solutions, VERIQA RT EPID will enable a true 3D dose verification from the acquired EPID images by reconstructing the dose in the patient anatomy and comparing it directly with the planned dose. EPID measurements can be performed both before (“pre-treatment”) and during patient treatment (“in vivo”), making it possible not only to detect clinically relevant errors unnoticed during pre-treatment verification, but also to quantitatively assess their dosimetric impact. “The EPID dose back-projection algorithm of VERIQA RT EPID will offer a double benefit,” states Igor Olaciregui-Ruiz, member of the EPID Dosimetry Group at NKI-AVL. “It will verify treatment delivery by using in vivo EPID measurements as well as increase efficiency in pre-treatment verification by using EPID images acquired “in air”, thus eliminating the need for phantom positioning and re-planning.”
As a true 3D EPID dosimetry solution, VERIQA RT EPID will also allow clinical users to calculate dose-volume histograms (DVH) both pre-treatment and in vivo. “The new VERIQA module RT EPID can be seen as a double-edged sword”, adds Anton Mans, medical physicist at the Radiation Oncology Department of NKI-AVL. “It will provide the radiotherapy treatment chain with an extra safety net while at the same time reducing the overall QA workload.”
The back-projection algorithm of VERIQA RT EPID is a clinically proven and well-established method, which has been successfully used at NKI-AVL in more than 72,000 patient treatments since 2006.
“Patient safety and workflow efficiency are key issues in any radiation oncology department today”, says Dr. Tobias Schüle, managing director of PTW. “By joining forces with NKI-AVL, we continue to deliver intelligent patient QA solutions that address these needs. Our partnership pairs PTW’s strength in the development of high-precision dosimetry technology with NKI-AVL’s long-term scientific and clinical expertise in 3D EPID dosimetry.”
The VERIQA software platform by PTW provides medical physicists and radiation oncologists with an automated, single-source solution for patient QA – from visualization and contouring through all commonly used plan verification methods to documentation. With VERIQA RT EPID clinical users will have an additional, highly efficient dose verification tool at hand, giving them the flexibility to choose the best verification method for their patient treatment plans.
For more information about PTW’s VERIQA patient QA platform, visit www.ptwveriqa.com.
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