By Tadao Kakizoe / Special to The Yomiuri ShimbunRadiation therapy, or radiotherapy, as part of cancer treatments has dramatically advanced since around 2000. For example, there has been remarkable progress in the field of imaging diagnosis, using such methods as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). As a result, it has become possible to determine the exact location and shape of tumors in each patient’s body.
At the same time, intensity-modulated radiation therapy (IMRT) has been developed for delivering precise radiation doses to a troubled spot in the body to kill the targeted malignant tumor based on its specific shape, while causing little damage to surrounding normal tissue.
The fusion of such high-precision radiotherapy solutions has led to a marked improvement in cancer treatments.
In Japan, as the population continues to quickly age, there has been an increase in the number of elderly patients developing cancer, increasing interest in radiation therapy that is less invasive than surgery.
Radiation therapy requires the presence of specialists called medical physicists who play an important role with their qualified knowledge about medical radiation physics in particular. They specialize in developing plans, in coordination with specialist doctors called radiation oncologists, for radiotherapy treatment to be applied in the safest and most effective manner. It is their responsibility to ensure that such plans do not have problems.
Only 22 experts per prefecture
In fiscal 2008, the medical fee reimbursement system under the nation’s public health insurance regime was revised to cover high-precision radiotherapy. Ever since then, Japanese society has had high expectations for medical physicists certified to provide and verify advanced and complex treatment plans. It should be noted that irradiation equipment used in radiotherapy is operated by medical radiology technicians.
The Japan Radiological Society (JRS) began qualifying medical physicists in 1987. Then in 2009, the JRS and two other related societies set up the Japanese Board for Medical Physicist Qualification (JBMP). Over the past three decades, a total of 1,057 medical physicists have been qualified in the country. More than three-quarters of them already had experience as medical radiology technicians, while the others had been science and engineering graduate school students.
The total is far from enough. Japan has not been able to cope adequately with the advancement of, and qualitative and quantitative improvements in, radiation therapy. Simply divided by the number of prefectures, there can be only about 22 medical physicists per prefecture. But most of them apparently prefer to work in urban areas, with regional hospitals desperately suffering from a chronic shortage of medical physicists.
For several years from around 2000, the country witnessed a rapid series of incidents in which patients undergoing radiation therapy suffered dangerous exposure because of incorrect or excessive radiation doses. This was due to the insufficient number of medical physicists. As far as publicly disclosed cases were concerned, there were more than 10 serious accidents and more than 700 victims of inaccurate radiation. Such harm inflicted on cancer patients by the absence of sufficient radiotherapy infrastructure must never be tolerated.
The series of medical errors led to the realization that the root cause was the shortage of qualified personnel in the field of radiation therapy, in general, and in particular that of medical physicists, whose presence is imperative to better control the precision of treatment.
Lagging behind U.S., Europe
Now, let’s look at the circumstances surrounding medical physicists abroad.
Physicists have been involved since the early days of U.S. and some European efforts to develop radiotherapy equipment and technology, improving precision management and enhancing the quality of treatment.
In Britain, the Hospital Physicists’ Association was founded in 1943, mostly by physicists. In the United States, the American Association of Physicists in Medicine was inaugurated in 1958. These groups came into being, reflecting the common understanding that there must be a group of specialists — medical physicists — in the radiation therapy area specializing in controlling massive doses of radiation delivered to each patient in a safe and effective manner.
In the United States, the American Board of Radiology now qualifies as medical physicists candidates who meet the following credentials: They have earned master’s degrees in science and engineering, passed the qualification examination and had two years of clinical training at accredited medical institutions. There is almost no difference between the Japanese and U.S. qualification procedures, but, nonetheless, the United States now has about 5,000 medical physicists, about five times the total in Japan.
Of the U.S. total, about 80 percent engage in radiation therapy practices. Many of them are doctorate degree holders concurrently working in clinical settings and in projects to develop new technologies in cooperation with university and corporate researchers. Undoubtedly, this is one of the reasons why the United States continues to be the world’s leader in the development of radiotherapy equipment.
New York-based Memorial Sloan Kettering Cancer Center — the world’s oldest and largest private cancer center — publicly discloses that it has 42 radiation oncologists and 28 medical physicists. The number of radiotherapy patients it treats a year surpasses the combined total of such patients treated annually at the National Cancer Center Hospital in Tokyo’s Chuo Ward and the National Cancer Center Hospital East in Kashiwa, Chiba Prefecture.
In some European countries, including Germany, a national qualification system is in place for medical physicists.
The leading cancer hospitals and university hospitals in the West carry out radiation therapy by employing a sufficient number of medical physicists, who are exclusively responsible for procedures for high-precision radiotherapy, such as irradiation plans in radiation therapy and precision management.
Cancer Control Law
In Japan, too, the importance of medical physicists has been widely recognized in recent years. The government adopted the first Basic Plan to Promote Cancer Control Programs shortly after the Cancer Control Law came into effect in April 2007. It said, “To cope with the application of advanced radiation therapy, it is desirable [for the country] to secure human resources that can draw up radiotherapy treatment plans and help improve the physical accuracy [of medical irradiation].” This means that the government had recognized the necessity of medical physicists at the national level.
Nevertheless, there have yet to be sufficient efforts to provide an environment in which Japanese medical physicists can maximize their ability to contribute to the development of radiation therapy in the country.
A survey conducted in 2011 by the Japanese Board for Medical Physicist Qualification found only 18 percent of medical physicists in the country “exclusively” assumed their primary duties such as designing treatment plans, 41 percent did so “concurrently” while working as medical radiology technicians and about 40 percent did the work of radiology technicians alone.
The findings of the survey showed that many medical physicists in Japan were too busy working as radiology technicians to do their primary duties as medical physicists, regularly forcing them to work overtime. If such overwork causes a medical error in radiotherapy, the victim will be the patient. Though I am not a radiotherapist, I have to say that such circumstances surrounding medical physicists are deplorable.
To improve the situation, I would like to offer a three-point recommendation. First, the qualification system for medical physicists should be raised to a national system instead of the undertaking of a private-sector organization. Once a national qualification system is in place, the importance of medical physicists can be recognized further across the country, thus helping establish a social status for their profession.
Second, medical institutions providing radiation therapy should be obliged to have a permanent system to assign medical physicists who will exclusively carry out their primary duties. Third, each medical institution should be required to specify a medical physicist’s job classification and position within the entity as a medical professional.
When the three proposals are realized, I expect the number of people pursuing careers as medical physicists to increase. If such a positive development occurs, the quality of radiation therapy will improve, resulting in a drastic improvement in cancer treatment. At a time when society is quickly aging with increased demand for less invasive remedies, including radiotherapy, we will be able to sufficiently secure specialists qualified to meet such demand.
Medical physicists are “unsung heroes and heroines” whose presence is usually invisible to patients in clinical settings. It is an urgent task for Japanese society to create an environment in which they will be able to maximize their ability as medical professionals.
Special to The Yomiuri Shimbun