In the first presentation, James Borgstede from the University of Colorado, examined a medical physicist's role within diagnostic imaging. "Medical physicists are an integral part of a radiology department," he told the audience. As well as being responsible for areas such as quality, safety and equipment selection, medical physicists have contributed to dose reduction for both patients and staff.

Borgstede emphasized that "the importance of fundamental physics is not going away". But looking ahead, he noted that diagnostic radiology is shifting from an anatomic to a physiological speciality – and that diagnostic physicists must move with it. In addition, increasing research collaboration is expected between radiation oncology and diagnostic radiology.

Opportunities for such collaborations include innovative adaptations of mature technologies, for instance the use of MRI techniques such as diffusion weighted imaging, spectroscopy and tractography for tissue analysis. Other examples include MR and ultrasound elastography, contrast-enhanced image analysis, dual-energy CT and fusion of multiple modalities.

"Often, it is the medical physicists who perform the basic science research that's then translated into the clinic, and this will continue," Borgstede noted. He pointed out that in a recent issue of the journal Radiology, 13 of 29 articles (that were not obviously physics-focused) had a physicist as an author.

He described some traditional physics-radiology collaborations that will continue to be important, such as nuclear medicine, where development of new radiopharmaceuticals for imaging and therapy provides an opportunity for collaboration on motion reduction, dosimetry and attenuation correction. Functional MRI and MR tractography are also rich environments for future collaborations, he noted.

Borgstede suggested that the next new modality to be introduced into the clinic is in fact "quality". "Medical physicists ensure quality – they have in the past and will do in the future," he explained. Physicists can also contribute to advances in data analysis and management, as well as developing artificial intelligence and machine learning techniques.

There are some challenges, however, including the fact that most medical physicists currently work in radiation oncology, with only about 25% in diagnostic imaging. In addition, for medical physicists to continue to ensure quality and safety, they must have adequate access to the clinical equipment.

Looking ahead, Borgstede emphasized that diagnostic medical physicists must be an integral part of the clinical team. "In future, we have to put a face on the medical physicist and the value that all of you bring to diagnostic care," he concluded.

The marriage of imaging and treatment
Next up, ASTRO president Brian Kavanagh from University of Colorado shared his thoughts on the medical physicist's role in radiation oncology, with an emphasis on breaking down the silos between therapy and imaging. Kavanagh surprised the audience by asking their thoughts on what was the wedding of the twentieth century – perhaps that of Prince Charles and Lady Diana Spencer? The delegates appeared unconvinced. "No, the wedding of the twentieth century was the marriage of imaging and treatment in radiation oncology," he said. "There is no single more important event in terms of combining those two sides of medical physics."

He went on to describe the emergence of image-guided radiotherapy (IGRT) and how techniques such as kilovoltage imaging of fiducials and cone-beam CT have developed to provide near real-time visualization during treatment. "The field of radiation oncology would be stuck in a two-dimensional 1970s rut without the wonderfully synergistic collaboration between imaging and therapy physics," Kavanagh added.

But it's not just a case of imaging techniques enhancing radiotherapy. Kavanagh also described how radiation oncology methods are being exploited to advance imaging. Examples include the use of 4DCT scanning to characterize pulmonary nodules during lung screening, or for ventilation assessment prior to surgery.

Noting that his presentation title also mentioned "value" – often defined as quality divided by cost – Kavanagh rounded up by sharing his personal opinions on how medical physicists can add value to the process of care in radiation oncology.

"To improve quality, problems should be identified first and then possible solutions tested," he explained, noting that often we can end up with a solution searching for a problem. "Sometimes, the implementation of new technology has moved forward at a pace that exceeds its support by clinical evidence that meaningful clinical benefit has been achieved."

"On the front-line clinical side, some new technologies can potentially help reduce operational costs rather than add expense, but it will take some courage and leadership to find the best path forward in that direction," Kavanagh added.

What is a medical physicist?
The final speaker, Paul Naine from Elekta, discussed the role of the medical physicist within industry. He began by looking at existing relationships between medical physicists working in research, industrial and clinical environments.

Highlighting physicists' collaboration, Naine described the same values but different focus areas that medical physicists have across the field. Medical physicists within research tend to focus on concepts rather than products, he explained, and then feed these concepts into industry. Here, the medical physicists are more product-focused and turn these ideas into devices and systems for the clinical environment. Clinical physicists, meanwhile, are more patient focused, concentrating on how to treat in the most effective and safe manner.

"The same values make a physicist a physicist regardless of their job title," Naine noted. "We should not just focus on what we do, but how we do it."

Naine introduced the idea of "complex adaptive systems", in which a large group of agents who aren't formally organized work together as one. As an example of such behaviour, he cited the emergence of CT-based image guidance in radiotherapy. "Someone had the idea, the vendors made the products, but who was 'in charge' and decided that it would become the de-facto standard of care?" he asked.

So how do physicists fit into this model of a complex adaptive system? The average physicist, Naine said, will have high intellectual and analytical capability, lower emotional intelligence and high levels of innovation. What's important is to recognise and maximize these attributes, to communicate, teach and share a unified vision.

To determine the nature of this shared vision, Naine examined the vision statements of AAPM, RSNA and ASTRO, noting that all mentioned education. He then looked at the statements from commercial companies, clinics and other professional societies, and saw common themes in all.

Next, Naine applied physics to the problem. He created a word map from all of the vision statements and sent it to 30 physicists, asking them to use this map to create a mission statement for physicists in industry. The top three replies were: "promote and educate in radiation oncology"; "promote patient healthcare"; and "promote education and research in cancer care".

To broaden the input into this statement further, Naine conducted a live poll of the audience, asking them to pick between the three. Of 323 audience members who voted, 41% picked the third option, and 50% voted for the second: to promote patient healthcare. "We can use this information to drive us forward as a complex adaptive system," he said.

"So what is the value of the medical physicist in industry? The same as the value of a medical physicist anywhere else," he concluded.

Related stories

• AAPM: showcasing the 'Best in physics'
• Medical physics: past, present and future
• Women in medical physics: the current status
• The expanding roles of medical physicists