Medical physicists have long had an integral role in radiotherapy. In recent decades, medical physicists have slowly but surely stepped back from direct clinical responsibilities in planning radiotherapy treatments while medical dosimetrists have assumed more responsibility. In this article, I argue against this gradual withdrawal from routine therapy planning. It is essential that physicists be involved, at least to some extent, in treatment planning and clinical dosimetry for each and every patient; otherwise, physicists can no longer be considered clinical specialists. More importantly, this withdrawal could negatively impact treatment quality and patient safety. Medical physicists must have a sound understanding of human anatomy and physiology in order to be competent partners to radiation oncologists. In addition, they must possess a thorough knowledge of the physics of radiation as it interacts with body tissues, and also understand the limitations of the algorithms used in radiotherapy. Medical physicists should also take the lead in evaluating emerging challenges in quality and safety of radiotherapy. In this sense, the input of physicists in clinical audits and risk assessment is crucial.

In recent decades, medical physicists have slowly become further removed from direct clinical responsibilities in planning radiotherapy treatments. This change has been more prominent in countries in Western and Northern Europe, somewhat less evident in Southern Europe, and only marginal in Eastern Europe.

Previously, physicists handled all aspects of the treatment planning from start to finish. Over time, however, this model has steadily given way to a new structure in which other specialists and technicians have assumed many of these responsibilities. While the reasons for this transformation are many and varied, medical physicists themselves are undoubtedly at least partly responsible.

Not everyone agrees with the notion that medical physicists have become too distanced from clinical work. Bortfeld and Jeraj argue that the real problem in medical physics is not insufficient clinical involvement, but rather that the research and academic aspects of the profession are weakening. Despite these arguments, I contend that there has indeed been a shift in the responsibilities of medical physicists.

One of the primary reasons that medical physics has become ever more distanced from its original, clinical role—in which the physicist was closely involved in treating patients—is the emergence of advanced technologies and the challenges that these technologies present. The work of medical physicists in the clinical setting has become increasingly less clinical. This is particularly evident in radiotherapy, where physicists were once responsible for developing treatment plans for all patients, but now have a more supervisory role in treatment planning. This change has altered how physicists are perceived by other members of the clinical staff, and it might even have a negative impact on the job positioning of physicists in the hospital, where the most important responsibilities are considered those that directly relate to patient care and treatment.

The discipline of radiation oncology has changed tremendously since the discovery of the therapeutic value of X-rays around the turn of the 20th century. While contributions to the advance of radiotherapy have come from experts from a variety of fields—including clinicians and biologists—it seems safe to say that the innovations of physicists have been essential.

From the very beginning, physics has had an important role in radiotherapy.4 The early discoveries of the value of ionizing radiation in the treatment of cancer were made by eminent physicists such as Wilhelm Roentgen, and Marie and Pierre Curie. As a result, physicists were closely involved in developing radiotherapy treatments and protocols. The typical job titles of these early physicists—e.g., radiation physicist, clinical physicist, and medical physicist in radiotherapy—underscore their importance. The physicist was a key member of the treatment team and, more importantly, was involved in every case without exception.

Until the advent of computerized treatment planning and the sophisticated imaging methods made possible by computers, these early physicists performed most of their planning tasks manually. Consequently, developing an individualized treatment plan was not only time-consuming (early sources, such as kilo-voltage X-ray units, were not automated and required that the physicist perform frequent dosimetry and output dose checks), but also highly challenging. In order to create an effective treatment plan, it was necessary for the physicist to have an adequate understanding of both biology and anatomy, in addition to the ability to visualize patient anatomy in three dimensions. Medical physics has a long and storied tradition in radiotherapy, and it is important that the clinical team not lose sight of that fact. Sophisticated treatment planning systems make it easy to forget that the people who designed the algorithms and truly understand these systems are mainly medical physicists. It is essential that physicists continue to be involved in performing treatment planning and clinical dosimetry. Such an approach is not intended to exclude radiotherapy technicians, especially those with advanced training .It is clear that technicians have an important role to play. However, it is imperative that certain clinical key responsibilities be performed by the profession of medical physics.

As physicists, we must possess a thorough understanding of human anatomy and physiology in order to be competent and equal partners to our clinical colleagues, the radiation oncologists. However, unlike our physician colleagues, we must also have a comprehensive knowledge of the physics of radiation as it interacts with body tissues and understand the limitations of the algorithms used in radiotherapy. Without such knowledge, we cannot hope to be treated as equals and to fully participate in clinical treatment planning. We must be confident in our knowledge, competence, and skills and be able to defend and sustain our opinions when discussing the best technological approach to each particular clinical situation.

Medical physicists should also take the lead in evaluating emerging challenges associated with radiotherapy quality and safety. They must be involved in clinical audits and risk assessment. Education has a crucial role in medical physics. Physicists need proper and consistent education before joining a medical physics department, and thereafter both postgraduate education and life-long continuous education are essential as well.

Regards,

Eliza Miller

Managing Editor

Journal of Medical Physics and Applied Science