Fujitsu Laboratories, Ltd. Today, in collaboration with researchers from the University of Toronto (U of T), announced the development of a technology to drastically streamline the creation of radiation treatment plans for gamma knife radiosurgery using Fujitsu’s quantum-inspired computing technology Digital Annealer, which quickly solves combinatorial optimization problems .
Gamma knife radiation therapies are used to treat diseases such as brain tumors and arteriovenous malformations. Creating treatment plans using traditional methods is often tedious and time-consuming, and doctors must spend time making careful and detailed adjustments to determine how much radiation to deliver to a target while minimizing the dose to surrounding tissue.
However, with the newly developed technology, clinicians can create treatment plans in about a minute, maintaining the accuracy of traditional methods while calculating a large number of possible combination patterns of where and how much dose to deliver with the Digital Annealer.
By relieving healthcare professionals from creating faster, more accurate treatment plans, they can invest more time and energy ensuring that patients receive the most effective and humane care possible. In the future, researchers at Fujitsu Laboratories and U of T will continue to test the effectiveness of this technology based on additional patient data and ultimately develop technologies that actively contribute to the improvement of medical science and society at large.
background
Gamma knife surgery is used to treat brain tumors and other diseases because it is non-invasive and provides a highly precise method of delivering radiation. By using 192 different sources of gamma radiation aimed at different points, the dose for the affected area can be maximized while the dose for the surrounding healthy organs is kept very low.
Parameters such as position, shape and radiation dose must be taken into account in order to achieve an optimal dosage for the affected area. The number of possible combination patterns is enormous, however, and in current medical practice doctors create treatment plans by manually repeating parameter adjustments based on their previous experience. This process can take anywhere from 1.5 to 3 hours to create a plan that will suit the individual needs of the patient and place a heavy burden on healthcare professionals.
While the doctor prepares the treatment plan, the patient may also have to wait, often with a frame attached to the head to restrict movement, which can lead to physical discomfort. It is also necessary to secure medical personnel to prepare patients for treatment and to ensure that the frame stays in place.
In recent years, new tools have been developed to simplify this process – for example software that automates the creation of treatment plans. In the field, however, it often remains the case that the generated plan still requires doctors to manually change and adjust the plans.
Since 2017, Fujitsu and U of T have been working together in a strategic partnership that focuses on research in the field of quantum computers. With this latest initiative, the parties have worked together to develop technology to support the use of the Digital Annealer to create treatment plans for gamma knife therapies. Researchers at U of T and its medical facilities studied and developed methods to translate Gamma Knife optimization into combinatorial optimization, a format that is understandable with the digital annealer technology developed by Fujitsu.
About the newly developed technology
U of T researchers, through their methodology and the use of Fujitsu’s Digital Annealer technology, have developed the following technology to create treatment plans at high speed while maintaining the same level of accuracy as treatment plans made by experienced clinicians.
1. Using the physical properties of the human body (dose profile), the shot shape is modeled during the gamma irradiation.
In the past, it was believed that shots (concentrated area of gamma rays) formed by multiple gamma rays are perfectly spherical during the shot positioning process. However, it has been found that the sphere is not necessarily perfect due to the influence of moisture in the human body. The newly developed technology determines the position of recordings using shot shapes that reflect the physical properties of gamma rays in the human body. This can help create more accurate treatment plans.
2. Optimization of the radiation parameters with the digital annealer
In the past, during the process of determining the shot position, a plurality of gamma ray irradiation positions (position of the shot) were successively determined; The position of the first shot was determined and the position of the second shot was then determined to include the remaining part of the affected tissue as much as possible. However, this may not result in the optimal number of shots or positions.
In contrast, the Digital Annealer allows users to search for the locations of all recordings simultaneously at the beginning, resulting in a more accurate, overall optimized treatment plan. It is also possible to obtain an optimized solution for the parameters of the beam shape, which allows the rapid creation of a treatment plan that optimizes the dosage for each patient.
In a study of 49 cases of auditory nerve tumors, U of T researchers compared the newly developed technology with the conventional method. Referring to an index of the accuracy of the radiation output, the technology developed was found to be as accurate as the manual planning. While the manual creation of a plan took 1.5 to 3 hours, this could be reduced to around 2 minutes with the newly developed technology.
By supporting the preparation of the plan with the newly developed technology, the time required for treatment with gamma knives and the stress on patients and medical professionals can be drastically reduced. A reduction in personnel costs for hospitals can also be expected.
future plans
Going forward, researchers at Fujitsu Laboratories and U of T will continue to validate the effectiveness of this technology with data from more patients and continue to develop technologies that have the potential to contribute to medical science and society at large. Future potential projects include shortening the time it takes for Gamma Knife treatment processes themselves in lieu of treatment plans, or applying this technology to other radiation therapy methods.
Source:
Fujitsu Laboratories, Ltd.
