A cutting edge medical imaging technique that provides for ‘in-room images’ during a patient’s cancer treatment process and which contributes to more accurate targeted radiotherapy treatment, helping to minimising radiation exposure to healthy tissues, is the focus of an IAEA publication issued last week.
Titled “Introduction of Image Guided Radiotherapy (IGRT) into Clinical Practice”, this is the first publication by the IAEA on this topic. It covers a number of areas related to this specific type of advanced imaging for cancer treatment, providing guidelines, methods and procedures to be followed by health personnel in radiotherapy departments, and the preparatory steps to be taken during the entire imaging process in the treatment room from start to end.
“One of the main advantages of IGRT is that it allows the radiation oncologist to reduce the amount of surrounding healthy tissue receiving the high dose of radiation intended for the tumour,” said May Abdel-Wahab, Director of the IAEA’s Division of Human Health. “If we know exactly where the tumour is every day of treatment, we can reduce the margin surrounding the treatment volume.”
Radiotherapy is one of the crucial techniques used in the treatment of cancer patients, either alone or in combination with surgery or chemotherapy. IGRT enhances the radiotherapy services offered and includes the use of scans and X rays to ensure that the patient is in the correct position before the commencent of treatment.
While the scan illustrates the size, shape, and location of the cancer and surrounding tissues and bones, the X ray provides the boney image of the treatment area for the radiation therapist to ensure that the patient is placed in the accurate position on the radiotherapy couch. If it is found that the position is even slightly incorrect based on the comparison of the scans and X rays, the couch can be adjusted to ensure precise treatment to be delivered. For example, the scans and X ray equipment can be fixed onto linear accelerators for the required imaging to be conducted and to verify the correct position of the patient, said Brendan Healy, a medical physicist at the IAEA’s Division of Human Health, who was the Scientific Secretary for this publication.
“Over the treatment course, IGRT information helps to monitor and adapt to changes that may occur during the course of radiation treatment and this in turn contributes to refining the treatment techniques and to improving the accuracy of the radiation field placement,” Healy added.
The publication provides a comprehensive overview of the required radiotherapy infrastructure and processes for a broad spectrum of radiotherapy services that would be of help to those professionals and administrators involved in the development, implementation and management of radiotherapy programmes, to further increase and achieve accuracy in delivering cancer treatment.
The publication includes the following information:
- A brief overview of the clinical evidence for IGRT;
- IGRT technology and treatment correction;
- How an IGRT programme can be established, and the equipment and protocols required;
- The roles and responsibilities of IGRT staff and the necessary training; and
- How IGRT is used in clinical practice, including an outline of the milestones and a description of quality assurance, uncertainties, planning margins, and justification and optimization.
There is also a self-evaluation questionnaire to determine an institution’s state of readiness to transition to IGRT, and well documented evidence on the improvements in accuracy and precision achieved with IGRT based on patient studies.
“Cancer cells or tumours can shift during treatment phases and having a record of scans and X rays helps to identify the correct patient position for radiation treatment,” Healy said. “The data generated through frequent imaging also constitutes an important learning opportunity for health professionals in this field to gain a wider understanding on how IGRT works and contributes to effective cancer treatment.”
The IAEA has received requests from its Member States for guidance on how to upgrade their radiotherapy facilities to IGRT. Support is provided through workshops and the trainings include theoretical and practical recommendations on identified steps on how to integrate IGRT into national radiotherapy services. There is also an IGRT e-learning module.
“The introduction of IGRT is a complex process,” said Abdel-Wahab. “The planning and implementing requires advance preparation, and this publication has indepth detail on each step, highlights the milestones to be reached by radiotherapy departments. These guidelines and milestones facilitate the process and represent the continuation of the work being undertaken by the IAEA to provide access to safer and higher quality treatment for the steadily increasing number of cancer patients in countries.”
The upcoming 2019 annual IAEA Scientific Forum in September will focus on cancer and will include topics relating to radiotherapy and medical imaging.