Radiation therapy methods (IMRT, IGRT, RapidArc)

Over the past 20 years, there has been a significant breakthrough in improving the methods of radiation therapy and its role in the treatment of cancer. Radiation therapy can be used in the treatment of 95% of cases of all types of malignant neoplasms. At EMC, we provide radiation therapy for all cancers except leukemia, regardless of the stage and prevalence of the process. Radiation therapy can also be used for palliative purposes to relieve the symptoms of the disease.

To provide the highest quality and modern treatment, we have assembled a team of leading professionals from Israel, Europe and the USA. The EMC Radiation Therapy Center is equipped with the latest generation of linear accelerators, including Varian EDGE, Russia's only system for radiation therapy and radiosurgery, which allows for the treatment of tumors with an accuracy of fractions of a millimeter, avoiding exposure to healthy tissues. Thus, the maximum possible effectiveness of treatment and a significant reduction in side effects are achieved.

Compared with some alternative methods in which the patient is forced to lie still for a long time (1 hour or more) during treatment, we are able to treat patients with the same accuracy and effectiveness in short sessions (3-5 minutes) for several weeks. Our specialists will always choose the best individual treatment option for each patient.

The EMC Radiation Therapy Center consists of world experts, state-of-the-art equipment, international treatment protocols and an individual approach.

What are the methods of radiation therapy?

• Rotational volume-modulated irradiation VMAT/RapidArc
• HyperArc technology
• Radiation therapy with modulated intensity IMRT
• Rotational radiation therapy with respiratory control Gated VMAT
• Radiation therapy under visual control (regularly obtained images of the tumor) IGRT
• iCBCT - iterative computed tomography (CT) in a conical beam
4D CBCT – CT in a conical beam with visualization of tissue movement during respiration (CT film) during a treatment session.
• Gated CBCT
• stereotactic radiosurgery SRS
• stereotactic radiation therapy SBRT/SABR

VMAT or RapidArc

VMAT technology is an advanced method of radiation therapy and one of the most modern methods of radiation treatment of malignant neoplasms. In EMC, the VMAT method is implemented on Varian EDGE and TRUEBEAM linear accelerators.

Before starting treatment, doctors use various imaging techniques (MRI, CT, or PET) to obtain images of the tumor and surrounding tissues. The contouring of the target organ and healthy surrounding tissues is performed manually by a radiotherapist, which allows taking into account the structural features of each patient. Based on the information received, medical physicists and radiotherapists create an individual radiation plan using special software.

Using VMAT, the radiation dose affects the tumor by continuously rotating the Gantry accelerator up to 360°. During the session, the thinnest metal plates (multi-petalled collimator - HD MLC) continuously move in the accelerator, according to a preset program, which protect healthy tissues. The direction of the beam beams and the positions of the collimator lobes are monitored throughout the procedure by the attending physician and medical technician.

The dose distribution is precisely shaped according to the shape and size of the tumor. Sessions may include one or more treatment arcs. The advantage of the method is not only in delivering high doses of radiation directly to the tumor and speeding up the treatment procedure, but also in minimizing the impact on surrounding healthy tissues, which in turn reduces side effects to zero and preserves organ functions. VMAT/RapidArc technology can deliver a radiation dose to the entire tumor in just one revolution in less than two minutes. This significantly reduces the exposure of healthy tissues and reduces the total procedure time to a few minutes.

IMRT

The widespread IMRT technology, or intensity modulated radiation therapy, uses spatial 3D scanning of the body to direct radiation beams at different angles to the tumor. At each of these angles, the radiation intensity is varied (modulated) using a multipole collimator (HD MLC), and the shape of the beam is changed to match the shape of the tumor. These adjustments make it possible to deliver the right dose of radiation to each part of the tumor.

HyperArc

Many patients with newly diagnosed cancer develop brain metastases. HyperArc technology has been developed precisely to make possible the rapid targeting and removal of isolated metastases in the brain, as well as to eliminate complications from irradiation of the entire brain. HyperArc uses all degrees of freedom to ensure the dynamic movement of the accelerator and couch for optimal utilization of the accelerator's non-planar beams. HyperArc technology is designed to replace the outdated SRS radiation technique (stereotactic radiosurgery), used, for example, in Gamma knife or CyberKnife treatment. HyperArc algorithms offer new ways to monitor multiple targets simultaneously, so that multiple metastases can be treated with a single radiation plan with increased dose accuracy. Thus, HyperArc is a time saver for the patient: there is no need to treat each head metastasis separately. Compared to the SRS technique, using HyperArc technology, the dose is delivered even more concentrated into the tumor (the dose gradient/decrease increases), which means even more healthy tissues are not exposed to radiation, and HyperArc plans demonstrate improved dose distribution between nearby targets.

Other innovative technologies for improving patient safety and treatment effectiveness are integrated into the workflow when using HyperArc. For example, in some cases, it is necessary to spend a valuable time resource during or before treatment to simulate treatment without delivering a dose in order to detect the risk of a collision. HyperArc solves this problem with a set of advanced visualization tools that display the treatment during treatment planning, eliminating the need for a trial run, which also saves valuable time and completely eliminates the risk of a collision with the patient.

EMC is already successfully conducting treatment using HyperArc technology. Only in our clinic, with the help of this technology, after all the necessary verifications have been completed, our highly qualified doctors and medical physicists can target DOZENS of brain metastases in one radiation session.

IGRT

IGRT technology, or radiation therapy with visual control, involves obtaining two-dimensional and three-dimensional CT images during the radiation therapy procedure, which greatly increases the accuracy of radiation delivery to the tumor. Unlike many medical cents, the team of doctors, X-ray technicians and medical physicists at the EMC uses the capabilities of the EDGE and TRUEBEAM imaging systems to clarify the correct positioning of the patient during each treatment session. Radiation therapy for some types of tumors, mostly small ones, and metastases can be performed in one session, in other cases, treatment is carried out in several short-term sessions.

Gated VMAT/RapidArc

The Gated RapidArc technique allows you to track the patient's breathing and take into account the movement of the tumor, quickly delivering a dose of radiation during continuous rotation of the radiator around the patient. This development is used to treat motile tumors with greater precision due to the ability to turn the beam on and off according to the movement of the tumor. Thanks to the use of a breathing tracking system, the patient can breathe naturally and calmly during treatment. Gated VMAT/RapidArc allows the use of high-precision treatment methods for many types of tumors, including lung tumors that move with each inhalation and exhalation.

4D CBCT

4D CBCT technology – CT in a conical beam with visualization of tissue movement during respiration (CT film). It is performed immediately before treatment on a linear accelerator to combine the therapeutic and planned isocenters with a stacking accuracy of up to 1 mm, taking into account the mobility of internal organs. With this tool, the doctor will be able to evaluate the accuracy of dose delivery right on the treatment table (assessing how the irradiated volume actually moves in comparison with the planned one), and, if necessary, make adjustments to the treatment process.

iCBCT

iCBCT technology performs iterative computed tomography (CT) in a conical beam. Advanced iCBCT algorithms developed using artificial intelligence reduce the noise and artifacts of CT images, providing them with higher quality than was possible using earlier standard CBCT approaches. The improved image quality, compared with a standard CT scan, provides more information about anatomical structures and helps to better visualize the location of the tumor and adjacent tissues, which means it is more accurate to adjust the required dose. In addition, improved soft tissue imaging reduces the time spent on patient positioning and eliminates the need for multiple scans, which again leads to more accurate dose delivery.

Thus, iCBCT reduces both the dose applied and saves time.

Gated CBCT

CBCT, which is performed only in certain phases of the respiratory cycle selected by the doctor, is an indispensable tool in the treatment using Gating technology. Previously, we could not see the "behavior" of the treatment volume at the desired phase depending on respiration, but now the doctor will be able to examine it in detail, assessing the accuracy of dose delivery, and, if necessary, make adjustments to the treatment process. In addition, due to the fact that Gated CBCT is performed at a certain phase of the respiratory cycle, there are no motion artifacts in the reconstructed images, which allows the doctor to examine the details of the treatment area. All this together significantly increases the accuracy of the administered dose and improves the quality of treatment.