The physical basis and future of radiation therapy

Abstract

ABSTRACT. The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued ''fuelling'' of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more ''professionalism'' in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.

Effect of irradiation on cytokine secretion and nitric oxide production by inflammatory macrophages

“…High-dose radiation is reported to suppress the immune system. Low-dose radiation enhances biological responses involving the immune system, enzymatic repair, physiological functions, and repair of DNA and protein damage (Bortfeld and Jeraj 2011;Hou et al 2014). Furthermore, low-dose radiation is used in a variety of clinical situations such as acceleration of wound healing for chronic diabetic ulcers and reduction of inflammation in chronic arthritic joint diseases (Bjordal et al 2003(Bjordal et al , 2006Schindl et al 1999).…”

Radiotherapy physics research in the UK: challenges and proposed solutions

“…There are a number of steps from the design of a potential development to clinical treatment, and the inclusion of the physicist in the multidisciplinary team is seen as crucial. Close interaction between the research physicist and the clinic is essential [5].…”

“…The answer is probably that both models can be effective. As proposed by Bortfeld and Jeraj [5], typically there will be a small number of posts at the ab initio end of radiotherapy research where research is best conducted by dedicated research staff in an academic programme, but there are several aspects of transitional research best conducted by physicists with clinical and research skills. The final step of rolling out a well-developed technique into all centres across the UK still requires local R&D skills and a national infrastructure in which the larger technique-developing centres support the smaller centres, which may have fewer staff.…”

“…Several factors have an adverse impact on the ability of radiotherapy physicists to carry out research, including a lack of research infrastructure, difficulties identifying an entry route into training, a lack of career pathways and the perception that radiotherapy is not a priority for research funding. Many of these problems are familiar ones in other countries and have been eloquently reviewed by Bortfeld and Jeraj [5]. These authors highlighted that a poorly structured and resourced medical physics community will result in considerable delays in the implementation of new technologies and techniques into clinical practice, with obvious negative consequences for patients.…”

What is the degree of innovation routinely implemented in Dutch radiotherapy centres? A multicentre cross-sectional study

“…4,5 Technological advances allow radiation oncologists to deliver radiation more precisely, increasing the dose to tumour targets and reducing the dose to normal tissues and critical structures. 5–7 Successful examples include stereotactic RT of intracranial and extracranial primary tumours and metastases and the incorporation of molecular imaging in treatment planning. 4,8,9 Organizational innovations, such as adopting the lean philosophy and introducing lean tools, can also help to decrease waiting times and increase safety and cost-effectiveness.…”