Even though nuclear medicine is comparatively a young medical specialty, the landscape of the field has changed many times over in the last 35 years. If we review our past, history will support my belief that we are in another evolutionary period. As nuclear medicine professionals, we need to embrace our strengths in imaging and treating disease using physiological principles to remain a viable and effective medical specialty.

Here's a brief review of the major technological and educational advances over the past few decades.

Technology overview

As I began my career in 1976, brain flows and scans accounted for almost half the procedures performed in the nuclear medicine department. Patients literally lined the hallways waiting for them. Then, a few short years later, the arrival of the first multi-slice computed tomography (CT) scanner significantly reduced the patient load for this procedure.

Soon after the first multi-slice CT scanner made its way into the hospital setting, whole-body nuclear medicine instrumentation became available clinically. Nuclear medicine could survey the body for infection using Gallium-67 and identify fractures and metastases with Tc-99m phosphate agents.

At approximately the same time, cardiac studies with sensitive multi-crystal gamma cameras evaluated the valves and chambers by measuring the first pass of a radiopharmaceutical through the heart to determine ejection fractions. These studies, called radionuclide angiograms, marked the beginning of nuclear cardiology.

Top: PET/MR 18F-Fluorothymidine image. Bottom: PET/CT F-18 FDG evaluating treatment for lymphoma. images/courtesy SNM

Nuclear cardiology progressed to evaluating coronary blood flow with the development of single photon emission computed tomography (SPECT) imaging using the radiopharmaceutical thallium-201. Nuclear cardiology became a subspecialty within nuclear medicine with the introduction of the Tc-99m cardiac imaging agents in the 1990s. These procedures became known as myocardial perfusion imaging.

Later in the '90s, positron emission tomography (PET) imaging moved from the research arena to the clinical environment. The usefulness of PET procedures in the staging of cancer and the evaluation of treatment was soon realized, and the discipline of nuclear medicine took another step in its evolution.

The development of computer software could fuse CT and PET images. These fused images provided the interpreting physician with physiological information, including anatomical detail.

With the advent of the first hybrid system using an external beam of X-rays to perform attenuation correction for PET imaging, the landscape of nuclear medicine changed again. This instrumentation allowed the acquisition of a CT procedure to be performed with the patient in the same anatomical position as the PET study making fusion imaging more accurate. Hybrid imaging using SPECT/CT also was introduced in the '90s and has increased the accuracy of many nuclear medicine procedures by providing anatomical detail.

Nuc med education

Similar to the evolution process of imaging equipment and computer software, education for nuclear medicine technologists (NMTs) also has changed significantly in the past 35 years. Nuclear medicine technology began as on-the-job training, but the field's leaders soon recognized the need for formal education. What was then the Society of Nuclear Medicine's (SNM) technologist's committee, which evolved into the SNM Technologist Section (SNMTS), demonstrated great insight and created a separate entity to oversee the education of NMTs.

In the 1960s, the Joint Review Committee on Educational Programs in Nuclear Medicine Technology (JRCNMT) was formed. Accreditation by the JRCNMT ultimately resulted in the newly formed technologist section, which lead to the development of the Nuclear Medicine Technology Certification Board (NMTCB). The formation of these two organizations was in direct correlation with the emerging profession of nuclear medicine technology.

The NMT educational model, as well as professional and pre-professional curriculum, also has undergone significant change since the formation of the JRCNMT and NMTCB. As the profession evolved, the requisite skills and knowledge needed to be competent as a technologist have continued to increase. As such, the SNMTS proposed in 2005 that the baccalaureate degree become the standard for entry-level NMTs by 2015.

One of the rationales behind this initiative is that 12-month programs and 60 to 70 credit-hour associate degree programs can no longer accommodate the exploding curriculum. Hybrid imaging has resulted in an increase in the knowledge base as well as specific skills needed in order to perform these studies. With the latest hybrid imaging incorporating PET with magnetic resonance (PET/MR), the knowledge and skills needed are increasing exponentially. The educational model to meet the needs of the future is becoming one that will result in multi-credentialing with either radiography or nuclear medicine as the base.

In January 2005, an SNMTS report on curriculum enhancements for emerging technologies indicated that CT, PET, and MR education are offered on a limited basis by a handful of existing educational programs. Yet, in an SNMTS survey conducted in spring 2011, most respondents have a PET/CT and/or SPECT/CT hybrid imaging system in their facility.

Effective January 2011, nuclear medicine technology educational programs are required to incorporate CT into their curriculum and the NMTCB and American Registry of Radiologic Technologists (ARRT) also have incorporated CT into the entry-level exam for NMTs. Continuing education is being provided to practicing NMTs by professional organizations in both CT and MR. And with documented clinical procedures, NMTs are eligible to sit for the specialty registry in CT and MR as administered by the ARRT.

In addition to hybrid imaging, molecular imaging and therapy are rapidly emerging as a projected part of clinical procedures. Molecular imaging involves the physiological principles of targeted biomarkers. These targeted biomarkers, which have the ability to image cellular processes coupled with emerging technologies, such as optical imaging, are paving the way to personalized medicine. The practice of molecular imaging will demand the addition of other coursework for technologists such as cellular biology and genetics--currently not part of the professional applied curriculum.

To expand the career opportunities and scope of practice for NMTs, a new pathway was created in 2005 with the introduction of the nuclear medicine advanced associate (NMAA). The NMAA is likely to have a huge role in the nuclear medicine department as the number of nuclear medicine physicians decline in some areas. This professional can assume more responsibility by providing direct care in the department by assessing, educating, and monitoring the patient during procedures at a higher level of responsibility than NMTs.

NMAAs have the potential to improve the diagnostic accuracy of nuclear medicine procedures because they will be directly involved with the patient at the procedural level and are educated on performing complete patient assessment, pharmacokinetics of drugs--including agents administered as part of the procedure, and analyzing the images.

Meeting challenges

As we look forward to the future, nuclear medicine will again evolve as new biomarkers and instrumentation are developed. The foreseeable model for educating NMTs will most likely include some form of multi-credentialing offered at the baccalaureate level.

Through the vision of George Segall, MD, president of the SNM, a Nuclear Medicine and Molecular Imaging 2020 Task Force was formed. The task force brought together a broad cross section of health care professionals to discuss the future of our profession and society and make recommendations that will serve as guiding principles to meet the challenges that lie ahead.

The 2020 Task Force consisted of the co-chairs of 10 specialized working groups representing physicians, scientists, technologists, industry, and other stakeholders. Each working group was responsible for analyzing the challenges and opportunities for nuclear medicine and analyzing the strengths and weakness of SNM as the professional leader for nuclear medicine and molecular imaging. The shared vision of the working groups demonstrated an integration of molecular and hybrid imaging into nuclear medicine, resulting in improved patient outcomes.

Kathy Hunt, MS, CNMT, is immediate past-president, SNMTS, and program chair, nuclear medicine technology, Baptist College of Health Sciences, Memphis, Tenn.