A good, unoriginal thought.
The title of this editorial is from Ruth I:16 (King James version of the Bible), and as with Ruth and Naomi, the disciplines of diagnostic radiology (DR) and radiation oncology (RO) were inexorably linked from their inceptions through the post–World War II era. In the late 1940s, Juan del Regato, MD, one of the early proponents of RO in the United States, corresponded with the American Board of Radiology (ABR) to request a separation of the disciplines within radiology; however, it was not until more than 3 decades later, in 1982, that the ABR administered its last general radiology examination. Qualifications for that examination required a minimum of 2 years of postgraduate training in DR and 1 year in therapeutic radiology (TR) (as it was known until 1987), or vice versa. It is important to note that the ABR did offer a certificate in TR when it initiated certification in 1934, but between 1934 and 1974, fewer than 20 certificates in TR were awarded in any given year, with most years seeing fewer than 10 being awarded (1). This is in contrast to the almost 200 RO certificates currently awarded annually by the ABR.
This issue of the journal is devoted to the incredible advances in RO enabled by adoption of increasingly sophisticated diagnostic imaging modalities. Unlike the early days of the introduction of equipment such as computed tomography (CT) simulators, which were often shared by the 2 disciplines, newer devices are more typically housed within the confines of the therapy department without immediate access to diagnostic colleagues and their input. Ironically, in the era that saw the introduction of CT, magnetic resonance imaging, highly selective interventional radiography, and computerized volumetric reconstruction of 2-dimensional imaging into the diagnostic armamentarium—as well as the very early exploration of the use of these modalities for therapy—the 2 disciplines were actually growing farther apart rather than becoming closer partners in clinical care.
The practice of RO is increasingly dependent on precise delineation of target versus nontarget tissues. At the same time, anatomic variations, patients with multiple comorbidities, many with imaging implications, and changes in motion and technique can cause significant alterations in image perception. We are increasingly concerned that training in image analysis, as is currently performed in many RO programs, is insufficient for present and future excellence in the practice of RO.
Before 1993, the Accreditation Council for Graduate Medical Education (ACGME) had a single residency review committee responsible for both DR and RO. Requirements for diagnostic imaging training in the RO program requirements, as promulgated by that final joint committee, specified only “access to diagnostic radiology,” without further details regarding actual curriculum content (2). Since 1993, accreditation of training programs and specification of program requirements for RO became the responsibility of the RO review committee. Some of this committee’s requirements, such as the precise number of new patients, simulations, and pediatric patients that each trainee must see before completing accredited training and becoming eligible for initial ABR certification in RO, have been prescribed specifically. By contrast, program requirements for training in all aspects of diagnostic imaging have no such specificity, indicating only that “the program must educate resident physicians in adult medical oncology, pediatric medical oncology, oncologic pathology, and diagnostic imaging in a way that is applicable to the practice of radiation oncology,” and that “there are multiple ways to meet this requirement,” including to “provide . . . a one-month rotation in both oncologic pathology and diagnostic imaging. . . ” (3). Practicing radiation oncologists routinely rely on pathology reports and must understand the elements and nuances of these reports, but many will rarely review actual pathology specimens for patient care decision making. Alternatively, information obtained from diagnostic imaging procedures is, by definition, integral to the routine daily practice of image-guided radiation therapy and all other RO procedures, except for clinical placement of cutaneous applicators.
The ABR is progressively adding additional image-related questions to its qualifying (computer-based) examinations in clinical oncology, including definition of normal and pathologic anatomy and appropriateness of provided treatment contours. As has always been the case, the certifying (oral) examinations are case management based, with an emphasis on image evaluation for usefulness in decision making regarding extent of disease, treatment planning, and follow-up. Over many exam administration cycles, it has become apparent that poor performance in both sets of examinations is often related to a lack of adequate knowledge in interpretation of the provided images, poor understanding of the added or diminished value of additional images and/or studies, and an inability to recognize differences in how images and disease processes are visualized based on technical alterations of the images employed for decision making. This concern has been previously noted (4).
In the absence of a formal ACGME-mandated curriculum for education in imaging for RO trainees, and with a clear understanding of the essential need for this knowledge set, the ABR plans to continue to add suitable imaging content to its RO qualifying and certifying examinations and the maintenance of certification online longitudinal assessment tool currently under development, with an anticipated rollout in 2020. In effect the ABR, through changing the examination, is, of necessity, forcing a change in curriculum. That being the case, we believe it is reasonable for appropriate stakeholders to develop a basic curriculum in the imaging education and skills necessary for radiation oncologists. The additional curriculum content could be provided in a variety of ways: (1) Requirements could be met by institutionally or departmentally established conferences, rotations, and/or didactic programming that would include all elements of the curriculum. (2) Regional teaching programs that would provide elements of the curriculum less likely to be available in smaller program-sponsoring institutions could be developed through shared resources. (3) “Crash courses” or “boot camps” could be established in centralized locations to provide some or all curriculum elements. This model has been tested for RO trainees in Canada with significant success (5). A similar model has been employed in the United States since the early 1960s to train DR residents in various aspects of their specialty not always easily available in their host institutions. Initially, these courses were provided at the Armed Forces Institute of Pathology, but following a reduction in federal funding for the institute’s programs, the course venue was shifted to the American College of Radiology through the American Institute for Radiologic Pathology. More than 20,000 DR residents have received training in the pathologic-radiographic imaging aspects of their discipline in this manner (6, 7).
Any of the approaches noted above could be undertaken by individual programs or groups of programs without ACGME-accredited program implications or external approvals. Other, more innovative programming, such as a side-by-side DR/RO oncologic imaging rotation with a shared core curriculum, could also be developed for cross-fertilization in both disciplines and offered in the postgraduate year 2 or 3 years. Even more intriguing would be to consider the more distant future of our specialty and try to imagine what the needs of our patients might be in the 2030s and 40s. No clinical specialty can be frozen in time; all experience evolutionary change, enlarging, branching, or shrinking. Interventional cardiology now eclipses cardiac surgery, a formerly dominant surgical specialty. Dermatology has evolved into a cosmetic as well as a clinical medical specialty. Primary care has demonstrated a progressive decline over the past several decades. It seems likely, if not inevitable, that some degree of merging between RO and other imaging and/or oncology-based specialties will, over time, evolve. This merging will not be a “top-down” revolution led by the ACGME, ABR, or the Society of Chairs of Academic Radiation Oncology Programs but rather a “bottom-up” revolution led by larger, more flexible programs, which will develop creative pilot approaches. The less creative or impractical pilots will wither, while those that fill a real need will thrive and propagate, to be later adopted into the mainstream. These changes could begin with cross-discipline fellowships, such as brachytherapy for interventional radiologists, interventional radiology for ROs, or nuclear medicine or cross-sectional scanning for ROs. These would not bring full certification but would allow practitioners to widen their practice and “diversify their portfolios.” Prostate brachytherapists, for example, might practice better if they could insert their own fiducial markers and spacers, offer additional energy-delivery treatments such as high-intensity focused ultrasound or cryosurgery, and biopsy the glands to assess response. Cross-fellowships would represent a “blurring of the edges” between specialties and a recognition that contemporary practice takes place in disease-focused cancer centers rather than “siloed” departments.
True hybrid programs blending DR and RO training from the outset have also been proposed. RO clinical training can now be completed in 27 months, as on the Holman Research Pathway. It may thus be possible to couple this abbreviated training with perhaps 16 months of nuclear medicine, or the 3-year DR core training, the latter being “thinned out” to reduce nononcologic work. It will be for individual institutions to define the program details and make proposals, but careful coordination with the ACGME and ABR will be essential to ensure that all requirements for program accreditation by the ACGME are met and that all requirements for initial certification eligibility by the ABR are fulfilled. Overall training would, of necessity, be longer than that for nonhybrid specialists, and it is likely that initially this will be a path chosen by few but with the potential for future growth.
Many RO programs have 6 or fewer residents, and we recognize that these suggestions may represent a challenge to many departments; some might even see them as an existential threat. Additional time devoted to image-based training may, realistically, require a reduction in time commitments to other elements of the program, entail time away from RO clinical responsibilities, likely produce a need for some time away from host programs, necessitate dialogue and rapprochement with our DR colleagues, and, potentially, add some cost to host departments. In an era of reliance on image guidance for RO, how can we not accept these modest burdens? A question beyond the scope of this editorial, but of intense current discussion and consideration, is how advances in artificial intelligence might affect any of these issues, and indeed, the clinical practices of RO and DR. A recent conference sponsored by the National Academies of Sciences, Engineering, and Medicine suggested that greater collaboration would also benefit DR trainees and providers (8). As did Ruth and Naomi, we must once again walk together.
