Important step towards MR Linac radiotherapy for lung cancer

MR Linac scanner with Ross Lydall inside

Ross Lydall, Health Editor of the London Evening Standard (pictured above), becoming the first healthy volunteer to be scanned by the MR Linac.

Researchers working with the MR Linac – a pioneering radiotherapy machine – have successfully developed treatment plans for patients with an advanced form of lung cancer.

The plans suggest that treating patients with locally advanced non-small cell lung cancer using the MR Linac system would be at least as effective as using conventional linac radiotherapy.

The study represents a key step towards bringing MR Linac radiotherapy to these patients in the clinic.

How it works

MR Linac systems use magnetic resonance imaging (MRI) to tailor the shape of the radiotherapy beam in real time, and can accurately deliver doses of radiation even to moving tumours.

However, the addition of the magnetic field can affect the way the beam works, so traditional treatment plans – which detail the areas to be targeted by the beam – need to be adapted accordingly.

Using patient MRIs and computer modelling, the researchers found that in every case it was possible to design an MR Linac treatment plan that gave an adequate dose of radiation to the tumour tissue, while avoiding giving too much to the surrounding organs.

The research was supported by Cancer Research UK and NHS funding to the NIHR Biomedical Research Centre at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust.

Research at the ICR is underpinned by generous contributions from our supporters. Find out more about how you can contribute to our mission to make the discoveries to defeat cancer.

Accurate targeting

Writing in the journal Radiotherapy and Oncology, the researchers from the ICR and The Royal Marsden explained how they prepared the treatment plans.

By analysing MRI scans of 10 patients currently undergoing radiotherapy on conventional linac systems – which deliver pre-planned shapes and volumes of X-rays to areas of the body – the researchers first calculated the volume of the tumours, and included a margin for where the disease may have spread at the microscopic level.

The researchers then added a further margin to allow for patient movement during treatment, simulated for treatment with both linac and MR Linac systems. In standard treatment planning, this margin is usually 7 millimetres.

For the conventional radiotherapy calculation, they used a 7mm plan, but for the MR Linac, they created two plans – one with 7 mm margins and another with estimated 3 mm margins – to allow for the system’s ability to adapt to movement in real time.

For each of the three scenarios, the researchers were able to design a plan to give a high enough dose to the tumour – but using the narrower margin on the MR Linac led to significantly lower doses of radiation affecting the surrounding tissues.

Tailored approach

The research team also designed a second set of treatment plans for an approach called isotoxic intensity modulated radiotherapy (IMRT).

Rather than give every patient a standard dose of radiation, isotoxic IMRT irradiates tumours until one of the surrounding organs reaches an exposure limit. This means that some patients can be given higher doses than they are currently, which can improve their prognosis.

By developing narrow-margin IMRT treatment plans for the MR Linac, the researchers established that it should be possible to target these patients’ tumours with higher doses of radiation than is currently possible, while avoiding more tissue from the surrounding organs.

Study co-leader Professor Uwe Oelfke, Head of the Joint Department of Physics at the ICR and The Royal Marsden, said:

“Current survival rates for patients with locally advanced non-small cell lung cancer are poor, making improvements in disease control essential.

“Our research shows that it is possible to develop treatment plans for these patients using MRI-guided radiotherapy machines, such as our new MR Linac.

“This state-of-the-art technology should enable us to deliver more personalised treatments to patients – increasing the dose to the tumour, while reducing the effect on surrounding tissues.”

Original Source: https://www.icr.ac.uk/news-archive/important-step-towards-mr-linac-radiotherapy-for-lung-cancer

Original Date: Dec 18 2017

Theraview TBI (Total Body Irradiation) Image Guided RadioTherapy System

Bring new confidence, reliability and safety on-line with TheraView®, the cost effective, low-dose, high resolution IGRT digital portal imaging and workstation software solution.

Acceletronics is North America’s full service and sales dealer for Cablon Medical’s latest TheraView Technology IGRT solutions.

The TheraView TargetCheck® IGRT workstation, which connects to your existing OEM portal imaging system, is delivered web-enabled to allow remote access for review and has image management networkoptions available that bring the full functionality of TargetCheck®, TheraView’s powerful beam alignment verification software, to remote workstations thru-out the department.

TBI_IGRT_PT

The TheraView TBI (Total Body Irradiation) Image Guided RadioTherapy System can help you significantly improve TBI treatment procedures and outcomes. This flexible, mobile stand-alone imager is part of the integrated TheraView imaging product suite and the only commercially available TBI product of its kind today. Faster results, fewer errors. Instead of simply producing a single image, our solution relies on Intrafraction Monitoring in the form of live video capture to provide high quality megavoltage (MV) images. Video captures can be stopped and restarted to accomodate for changes in the patient’s position – so there’s no risk of needing to repeat the entire patient setup procedure. This will deliver significantly greater efficiency, faster results and improved treatment quality.

The TheraView Couch Setup Assist (TCSA), is an optional hardware/software solution that enables a faster, more accurate positioning of your patient. With TCSA, you can enhance patient care by reducing time spent on the treatment table and the number of trips in and out of the room by the Therapist. TCSA helps position the patient quickly with precision, reducing setup misalignments during patient setup. TCSA integrates with most all treatment couches and all movements are retraceable from the main application.

For the department that needs an EPID installed on their existing Linac, the TheraView EPID for IGRT uses high reliability, less costly, radiation hardened, cooled C3D digital X-Ray camera technology for excellent, reliable and stable image quality, with a fiber-optic digital image transmission path to the workstation providing a virtually noise free image. TheraView mounts on any non-beam-stopper linear accelerator and provides superb real-time portal imaging. TheraView is DICOM-RT compatible with all popular image management systems and has motorized digitally controlled movements for accurate and easy set-up, use and stowage.

Continual development by the experts at TheraView consistently deliver advanced timely solutions with changing treatment protocols. With the Theraview TargetCheck® IGRT workstation, TBI Image Guided RadioTherapy System or Theraview EPID, manufactured by Cablon Medical (www.theraview.com) you can deliver the current and future technology treatments with accuracy, verification and safety. Please contact us to discuss your MV imaging needs and schedule an online demonstration, we can be reached via email at info@acceletronics.com or call us at 800-543-5144.

More information can be found on our website: http://www.acceletronics.com/medical/theraview-igrt-portal-imaging-system.php

and on YouTube Video: https://www.youtube.com/watch?v=R9_UAk8DMt4

December Specials 2017

First-in-human data validate MRI-linac

In May of this year, a research team at the University Medical Center Utrecht performed the first patient treatment using Elekta’s Unity, an MRI-guided radiotherapy system that integrates a diagnostic quality 1.5 T MR scanner with an advanced linear accelerator. Now the team has published details of the first four patient treatments, demonstrating the feasibility and clinical utility of the Unity MRI-linac (Phys. Med. Biol. 62 L41).

The Utrecht team treated four patients with lumbar spinal bone metastases, with a single fraction of 8 Gy prescribed to the target volume while minimizing dose to the spinal cord and the rest of the body. The treatments demonstrated the system’s ability to deliver precisely targeted radiation doses while simultaneously capturing the high-quality MR images that will allow clinicians to visualize tumours at any time, and adapt the treatment accordingly.

The MRI-linac at the University Medical Center Utrecht

The patients were treated with a 3- or 5-beam step-and shoot intensity-modulated radiotherapy (IMRT) plan. Plans were created while the patient was on the treatment table and based on the online 1.5T MR images, with the pre-treatment CT deformably registered to the online MRI to obtain Hounsfield values.

“These study results are very promising and we look forward to further advancing the clinical development of this transformative system, which has the potential to revolutionize the treatment of cancer,” said Bas Raaymakers, professor of experimental physics at UMCU. “These first clinical treatments show an outstanding level of dosimetric and geometric accuracy of the online IMRT planning and the radiation delivery based on the 1.5 T MRI guidance. This approach enables the optimization of dose to the tumour while reducing exposure of healthy tissue. To date, achieving this optimization has been the key challenge in radiation therapy.”

The team chose bone metastases as the first treatment site as these tumours can be clearly visualized on MRI while the surrounding spine bone can be detected on the integrated portal imager. In this way, portal images can be used to independently verify the MRI-based guidance and quantify the precision of radiation delivery.

They validated the geometric accuracy of online MRI guidance by comparing portal images of the IMRT segments with the MRI-based calculated projections. This revealed an average beam alignment of 0.3 mm with the target as defined on the online MRI, demonstrating the stereotactic geometric system accuracy. For each patient, the team performed the same quality assurance procedures for both the pre-treatment plan and the delivered plan, finding a mean difference of 0.4% of the calculated dose.

“These preliminary results are exciting and support the tremendous potential of Elekta’s MR-linac to address some of the historic challenges to improving the safety and efficacy of radiation therapy,” commented Kevin Brown, global vice-president of scientific research at Elekta. “The exceptional dosimetric and geometric accuracy reported in this study support the system as a transformative approach to radiation therapy that may allow more patients to receive optimum cancer care.”

Original Source: http://medicalphysicsweb.org/cws/article/research/70464

Original Date: Nov 15 2017

Original Author: Tami Freeman

Factors That Influence the Service and Maintenance of Radiation Equipment

There are several considerations to take into account when you’re servicing linear accelerators and maintaining radiation equipment. Linear accelerators and radiation equipment are critical and essential in any radiation oncology department but they are also quite expensive and complicated.

One of the biggest decisions to take into account is whether to rely on the Original Equipment Manufacturer (OEM) or to work with a servicing company whose main focus is servicing linear accelerators and maintaining radiation equipment.

While it may seem at first that the best cause of action would be to go with the OEM, there are several factors to consider alternative options such as:

Cost

Cost is a major factor to take into account and due to the complexity of servicing linear accelerators and maintaining radiation equipment; OEMs typically tend to charge a higher premium for service and maintenance.

Servicing companies on the other hand are able to offer a bundle of plans for you to choose from which can help to reduce costs, mitigate risk, or eliminate risk and protect your practice from unforeseen costs.

Focus of Service

The main business of OEMs is the manufacture and sale of equipment and equipment parts thus service and maintenance may not be the core of their business. With a servicing company whose main focus is servicing linear accelerators and maintaining radiation equipment, this facilitates greater efficiency and improved uptime.

Response time

The importance of medical equipment which underlies any medical facility is the optimal functioning of the equipment. Unforeseen machine breakdown can paralyze the operations of a practice. The speed at which medical equipment is returned to normal operating capacity is therefore critical.

For servicing companies, response times to servicing linear accelerators and maintaining radiation equipment is typically higher than OEMs since their services are structured to be available 24/7 with quick turnaround time for onsite responses.

Larger scope of operation

Most servicing companies have employed specialists and experts of different types of devices and brands so as to ensure effective servicing linear accelerators and maintaining radiation equipment. The service engineers are typically trained directly by the OEM manufacturers.

In addition, for practices that use different brands of oncology equipment, a servicing company is able to take care of the different requirements and specifications involved with servicing linear accelerators and maintaining radiation equipment in-house without involving different OEMS.

Flexible service contracts

Servicing companies are able to offer flexible service contracts which ensure comprehensive service for your oncology devices while controlling the service costs. Servicing companies are responsible for maintaining optimal uptime of the devices, carrying out scheduled maintenance and emergency repair service during the contract period.

The benefits of these flexible service contracts for servicing linear accelerators and maintaining radiation equipment include no charges for parts, effective cost control, scheduled preventive maintenance, no travel or call out charges, access to 24/7 support and optimal uptime guarantee for qualified devices. These flexible service contracts are therefore customized to meet the unique specifications and financial needs of your practice.

Learn more about Radparts and the variety of services and parts they offer to repair medical equipment including: linear accelerators parts, CT scanners parts, linac parts, and radiation oncology equipment at www.radparts.com. To contact one of our medical equipment repair specialists for parts or service call toll free 877.704.3838 for 24/7/365 support.

Tips When Purchasing Linear Accelerator Parts

There are several considerations to take into account when you are purchasing parts for radiation equipment including linear accelerators. Radiation equipment is critical and essential in running an oncology department and it is also quite costly and complicated.

One of the major decisions that you will need to make is whether to buy new or refurbished parts to repair and maintain your radiation department’s equipment. Refurbished linear accelerator parts are suited for both repairs and maintenance. The costs of replacement parts for radiation equipment are lower when purchasing refurbished parts. Refurbished equipment is ideal for medical companies that are starting out, purchasing additional pieces, research companies, veterinarians, and industrial purposes.

Advantages of Refurbished

Some of the reasons for buying refurbished linear accelerators and refurbished parts for radiation equipment include:

To Grow a Practice: Refurbished linear accelerator and refurbished parts free up resources and minimize costs as you upgrade your practice whether that involves opening a new center, a new treatment room, or spare equipment to have on hand.
Manage Expenses: Refurbished linear accelerators and refurbished parts help manage the risk of investing in costly new equipment during turbulent periods and help you stay afloat in times of financial constraints.
Flexibility: Refurbished linear accelerators and refurbished parts provide you the flexibility of having a backup system that you can fall back on when your existing system develops a problem.

What To Think about when Purchasing

There are many factors to consider when buying radiation equipment and parts for linear accelerators, CT scanners and other oncology equipment.

Proper Planning – There are several factors that go into the planning aspect as you make your buying decision. You need to identify and understand what your clinical goals are and what type of technology you will require delivering quality service. Factors to consider include whether you plan on going fully digital to the type of defined treatment field you want to achieve.

Site planning requirements is another factor to consider because installation of linear accelerator parts for radiation equipment requires important considerations such as room dimensions, power, local permits, water supply and future equipment technology.

The timeline for completing your project is critical for planning and executing milestones such as installation dates, equipment acceptance testing dates and going live with the linear accelerator parts. It is important to factor in some level of flexibility in your project timeline so as to account for unforeseen developments and challenges.

Your budget will determine the technology, manufacturer, and age of your equipment acquisition. A limited budget can influence you to go for refurbished linear accelerator parts for your radiation equipment. This also ensures available resources to effectively carry out other essential operations of your practice.

An Experienced Team – The successful implementation of linear accelerator parts requires good cohesion with various experts ranging from the equipment provider to the physics support team to the IT integration team to the clinical implementation team.

Have A Professional Do Install

It is important to ensure that the experts who are handling this implementation are specialists in their own field and have the requisite experience and expertise to execute. Perform due diligence background on the equipment provider for your linear accelerator parts for the radiation equipment to ensure maximum reliability and vendor accountability. Invest in an equipment provider that not only sells you the equipment but also provides post-installation support.

The building where Linac will be installed K Shijith

KOCHI: Cancer treatment in the city is gaining momentum. With the linear accelerator (Linac) going functional in a couple of months, cancer patients, who are undergoing radiation treatment, can hope for the best. Linac will reduce the duration of the treatment since it is more powerful than the machines like Cobalt which is used now. It delivers high-energy X-rays or electrons right at a tumour and shrinks it.

The thick wall will prevent the X-rays
from going out of the building  K Shijith

“More than 70 per cent of cancer patients require radiation therapy. Innovation on this front is very important. When we go for comprehensive cancer care for people, it is important to have the latest technologies in hand,” said K T Thomas Kannampallil, radiation physicist and RSO, General Hospital, Kochi.

The Linac machine, which will be installed in the General Hospital, has provisions that help it to apply radiation according to the size and shape of a tumour. A machine called multileaf collimator (MLC) is used for this purpose.

“After the machine is installed, which will take at least three weeks, we will begin the tests. The machine will be patient-ready after many tests and retests are conducted. These will span over two months. During this period the clinical approval for the treatment process has to be obtained from the Atomic Energy Regulatory Board,” said K T Thomas.A team of radiographers, radiation physicists and radiation oncologists will be operating the Linac.

Patient Benefits
Patients will get minimal exposure to radiation in the areas where they are not afflicted. Almost 70 cancer patients can be treated using the machine every day. The intensity of the radiation is gradually decreased over the period of treatment for the patients. Currently, over 1,300 patients routinely undergo radiation at the General Hospital. Apart from this, the patients looking for pain relief (Palliative) also undergo radiation therapy at the hospital. Once the machine is installed, it will come as a big relief to the patients belonging to the middle and lower middle-class from Central Kerala.

GST Issue
The machine, which is worth Rs 7.4 crore was brought to Kochi a few months back. However, a GST of Rs 1.46 crore was charged and this caused a delay in its installation. The issue has been sorted out with the hospital using its hospital development society’s fund to offload the machine from the Kochi port. The government has promised a reimbursement. The installation process began on Wednesday and all the pending permissions have been acquired. The total expense incurred for the installation of the machine is Rs 16 crore. This includes the cost of the machine, installation, supporting equipment and the building where it is being installed.

Linac lasts longer
The cobalt machine, which is being currently used, is radioactive and degenerates with time. Whereas the Linac machines use X-rays. It emits radiation only when the controller pushes the button. Operated from outside the room, only the patient will be exposed to the X-rays. Cobalt machines were also vulnerable to leakage. Linac doesn’t have those issues. The speed of radiation of the cobalt machine reduces with time.

“The machine will be placed in a building with walls made of concrete that are 2.4 m in thickness. If not the X-rays can penetrate the walls and reach the exterior of the building,” said Sajeesh, radiation physicist, General Hospital. Actually designed for nuclear tests, Linac is now helping cure cancer all over the world. The building has been built near the old RMO quarters in the vicinity of General hospital.

How does the equipment work?
The linear accelerator uses microwave technology (similar to that used for radar) to accelerate electrons in a part of the accelerator called the “wave guide,” then allows these electrons to collide with a heavy metal target to produce high-energy x-rays. These high energy x-rays are shaped as they exit the machine to conform to the shape of the patient’s tumor and the customized beam is directed to the patient’s tumor. The beam is usually shaped by a multileaf collimator that is incorporated into the head of the machine. The patient lies on a moveable treatment couch and lasers are used to make sure the patient is in the proper position. The treatment couch can move in many directions.

Original Source: http://www.newindianexpress.com/cities/kochi/2017/nov/01/zapping-tumours-precisely-1689510.html

Original Author: Gopika I S

Original Date: Nov 1 2017

November Specials 2017

Proper Maintenance for Linear Accelerators and Oncology Medical Equipment

Proper maintenance of medical equipment is extremely important if you want to get optimal results. The most important thing to keep in mind is that linear accelerator maintenance and oncology medical equipment maintenance requires a very specialized procedure and you should always consider the most reliable teams to get this done.

Medical Equipment Maintenance

The process of giving maintenance to this kind of equipment is quite complex. This is why you can’t simply give this task to any regular maintenance provider. Choosing one that is qualified and also capable of getting the job done for an affordable cost is going to be important.

If you are looking for a good linear accelerator maintenance provider and oncology medical equipment maintenance services, you need to take the time to search for the best possible results. This is going to require that you take your time and evaluate your options in your area.

The Search for Medical Equipment Service Technicians

A good way to get started with this search is to look at the online information they have available. Not finding a website or social media is always a red flag. Any business that is considered professional in modern times should have a website of their own or at the very least a social media page with all of their information.

Another good way to find out how good they are is to give them a call. Ask about their services and what the procedure is like. You should call at least a couple of different providers in order to get the best possible results. This is going to give you enough information to decide.

Any kind of equipment that is used for medical purposes needs to be handled very carefully. This is going to be the best way for you to maintain the most reliable results when you are looking to get your expensive equipment analyzed and checked for any problems.

Final Thoughts on Maintaining LINAC Systems and CT Scanners

Once you find a good team to give maintenance to your equipment, make sure that you can come up with a good deal that is going to be beneficial to both parties in the long term. This is going to be the best way for you to get maintenance done without having to worry about the hassles of hiring someone new all the time. This is going to be very important to make your equipment last longer.

Evaluating skin dose from the MRI-Linac

External-beam radiotherapy systems that that employ real-time or near real-time MRI guidance show much promise as a new technique to treat cancer. Prototype hybrid MRI-Linac systems are being evaluated as modalities to deliver high precision ablative radiotherapy.

Researchers at Sunnybrook Health Sciences Centre in Toronto are investigating the feasibility of using an MRI-Linac to treat breast cancer patients, using hypofractionated partial breast irradiation (HPBI). Sunnybrook’s Odette Cancer Centre is evaluating a clinical prototype of Elekta’s MRI-Linac. Its clinical staff believe that the system’s online visualization and tumour contouring capabilities, combined with the ability to reduce internal motion margins using multileaf collimator tracking or exception gating from real-time MR images, will be advantageous for treating intact breast tumours.

However, one concern is that treatment with an MRI-Linac can cause elevated radiation doses to the skin. The ever-present magnetic field can create electron return effects (ERE), in which electrons liberated at tissue–air and tissue–lung interfaces curl back on themselves and deposit larger radiation doses in tissue at these interfaces.

Sunnybrook’s Anthony Kim and colleagues

Medical physicist Anthony Kim and colleagues conducted a simulation study to determine the impact of the magnetic field on HPBI dose distributions. After evaluating a tangential beam arrangement (TAN), 5-beam intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), the researchers confirmed their hypothesis that the magnetic field increases the skin dose. The magnetic field had clinically negligible effects on radiation dose to the heart and the lung (J. Appl. Clin. Med. Phys. doi: 10.1002/acm2.12182).

Impact of the magnetic field

The researchers developed treatment plans for five patients who did not have surgery due to metastatic disease or severe medical comorbidities. They analysed a total of seven tumours close to the skin, with planning target volumes (PTV) of between 37.3 cc and 341.1 cc. For each tumour, treatment plans for the three beam geometries were optimized with and without a 1.5 T magnetic field, using the same PTV isocoverage for all six plans.

The authors used the same patient image data and target contours as used clinically. They evaluated two skin depths, 3 and 5 mm, to determine whether magnetic dose effects were more prevalent closer to the patient’s external surface.

All plans had acceptable PTV coverage. The authors reported that with the magnetic field on, the skin dose was considerably higher for the TAN plan compared with the IMRT plan, which in turn delivered a higher dose to the skin than the VMAT plan.

The skin dose correlated with the number of beam angles used. Specifically, skin dose can be reduced by increasing the number of beam entry angles. Hence, in the presence of a magnetic field, VMAT spared the skin more than IMRT, which in turn spared more than the TAN beam arrangement. Also, the researchers found that the ERE due to the magnetic field was greatest very near the surface of the skin.

The authors explain these phenomena by the fact that the ERE tends to have much less impact at the entry points compared with the beam exit points. Only the beam angles near the tumour created a higher magnetic field dose. The ERE had a much larger impact with TAN radiation delivery compared with IMRT or VMAT delivery when the beam angles were spread far more apart.

Based on their analyses, the authors stated, “The number of beam angles matter, and it is likely that beam arrangement also matters… Skin dose is significantly impacted not only by the magnetic field, but also varies with depth and when increasing the number of beam angles.”

The MRI-Linac is currently being installed at Odette Cancer Centre. “The installation will be completed soon, and in the early part of 2018 we will be conducting basic physics research and volunteer MR imaging, to evolve our understanding of this device ahead of treating patients,” Kim told medicalphysicsweb. “We have been able to do some basic groundwork with respect to how to best optimize these plans without adverse effects. This groundwork has been possible because of our access to the radiation treatment planning system (Elekta’s Monaco) that can simulate the MRI-Linac beam on actual patient data.”

Original Source: medicalphysicsweb.org/cws/article/research/70214

Original Author: Cynthia E Keen

Original Date: Oct 17 2017