Effective and efficient expertise
Commissioning of Linear Accelerators (Linac) and Treatment Planning Systems (TPS) can be time consuming and divert important resources away from providing direct treatment to patients. NPL has a team of radiation dosimetry and medical physics experts who can help NHS and other radiotherapy providers to address this challenge. NPL has more than 15 years’ experience, and a large database to compare your Linac data with. We offer support in the form of staff time, equipment and expertise to assist during the beam data acquisition process for your Linac and TPS commissioning. Additionally, we support Linac acceptance (CAT) and matching processes. We can provide an independent dosimetric subset of measurements for your Linac quality assurance (QA) baseline.
We understand the requirements for most of the TPS available in the market, both independent and linked to Linac manufacturers. We design the project for measurements with TPS modelling purposes, but also with model verification intentions. We work flexibly around your installation schedule and can support your local specialists by creating the fields that are not part of the standard settings in Linac consoles.
Typical set of data for X-rays and electron beams will be acquired according to the TPS measurements requirements, including:
• Profiles and depth ionisation and dose curves, electron isodose charts
• Square, rectangular and asymmetric - open and wedged fields
• Output factor measurements, including small fields
• Dose point measurements in reference and non-references conditions
• Scans of shaped fields for model verification purposes and fine tuning of beam model parameters.
We are capable of working with most 3D scanning solutions available. Regardless of the choice, NPL will create the relevant measurement queues for the tasks involved. Based upon your preference, we can work with your local measurement systems and detectors or bring our own, including 3D water phantoms and associated software. We have a set of detectors suitable for every type of measurements:
• Cylindrical and plane parallel ionisation chambers
• Small volume ionisation chambers for measurements in small fields
• Stereotactic, electron and photon diodes
• Secondary standard chamber and electrometers for relative and absolute output measurements
If you need to commission a mobile Linac or low-energy and medium-energy X-ray equipment, it will be possible to perform the beam data collection process in our laboratories in Teddington.
Bespoke service to meet your needs
We typically have one or two members of our staff on-site for two to four weeks, according to your measurement requirements. If you are having multiple installations, we provide two teams working simultaneously on two different Linacs.
Shortly after finishing the on-site work, we will provide a CD, USB or a large zip file, transferred by a secure server, with the raw and processed data we have collected. We also provide a comprehensive report with all the relevant details that will contribute towards your department commissioning portfolio. We keep you involved in the commissioning process and up to date with our progress.
As a Primary Standards Laboratory, we support your junior medical physicists, by providing an overview and some practical experience of the commissioning process. Before and after our on-site work, we are always available to respond to technical queries. Our registered clinical medical physicists can support your commissioning process on a consultancy-based agreement.
This service is available for conventional linacs and other radiotherapy devices. We also have a range of complementary services, such as photon and electron independent verification audits, as well as other clinical audits.
Find out more about NPL's Radiotherapy dosimetry audits
Find out more about NPL's Medical physics research