Nuclear medicine physicians, also called
nuclear
Nuclear may refer to:
Physics
Relating to the nucleus of the atom:
* Nuclear engineering
*Nuclear physics
*Nuclear power
*Nuclear reactor
*Nuclear weapon
*Nuclear medicine
*Radiation therapy
*Nuclear warfare
Mathematics
*Nuclear space
*Nuclear ...
radiologists
Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiatio ...
or simply nucleologists, are
medical
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practic ...
specialists that use tracers, usually
radiopharmaceuticals
Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which is ...
, for diagnosis and therapy.
Nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitting ...
procedures are the major clinical applications of
molecular imaging
Molecular imaging is a field of medical imaging that focuses on imaging molecules of medical interest within living patients. This is in contrast to conventional methods for obtaining molecular information from preserved tissue samples, such as ...
and molecular therapy. In the United States, nuclear medicine physicians are certified by the
American Board of Nuclear Medicine
The American Board of Nuclear Medicine (ABNM) certifies physicians as specialists in the practice of nuclear medicine. Diplomates of the ABNM are called nuclear medicine physicians. The ABNM is one of the 24 member boards of the American Board ...
and the
American Osteopathic Board of Nuclear Medicine.
History
In 1896,
Henri Becquerel
Antoine Henri Becquerel (; 15 December 1852 – 25 August 1908) was a French engineer, physicist, Nobel laureate, and the first person to discover evidence of radioactivity. For work in this field he, along with Marie Skłodowska-Curie and P ...
discovered
radioactivity. It was only a little over a quarter of a century (1925) until the first radioactive tracer study in animals was performed by
George de Hevesy
George Charles de Hevesy (born György Bischitz; hu, Hevesy György Károly; german: Georg Karl von Hevesy; 1 August 1885 – 5 July 1966) was a Hungarian radiochemist and Nobel Prize in Chemistry laureate, recognized in 1943 for his key role ...
, and the next year (1926) the first diagnostic tracer study in
humans
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
was performed by Herman Blumgart and Otto Yens.
Some of the earliest applications of radioisotopes were therapy of hematologic malignancies and therapy of both benign and malignant thyroid disease. In the 1950s
radioimmunoassay
A radioimmunoassay (RIA) is an immunoassay that uses radiolabeled molecules in a stepwise formation of immune complexes. A RIA is a very sensitive in vitro assay technique used to measure concentrations of substances, usually measuring antigen conc ...
was developed by
Solomon Berson
Solomon Aaron Berson (April 22, 1918 – April 11, 1972) was an American physician and scientist whose discoveries, mostly together with Rosalyn Yalow, caused major advances in clinical biochemistry.Rall JE. ''Solomon A. Berson''. In "Biographica ...
and
Rosalyn Yalow
Rosalyn Sussman Yalow (July 19, 1921 – May 30, 2011) was an American medical physicist, and a co-winner of the 1977 Nobel Prize in Physiology or Medicine (together with Roger Guillemin and Andrew Schally) for development of the radioimmunoassay ...
. Dr. Yalow was co-winner of the 1977 Nobel Prize in Physiology or Medicine (Dr. Berson had already died so was not eligible). Radioimmunoassay was used extensively in clinical medicine but more recently has been largely replaced by non-radioactive methods.
In 1950, human imaging of both
gamma
Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...
and
positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides ...
emitting
radioisotopes
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
was performed.
Benedict Cassen
Benedict may refer to:
People Names
*Benedict (given name), including a list of people with the given name
*Benedict (surname), including a list of people with the surname
Religious figures
* Pope Benedict I (died 579), head of the Catholic Chu ...
's work with a directional probe lead to the development of the first imaging with a
rectilinear scanner
A rectilinear scanner is an imaging device, used to capture emission from radiopharmaceuticals in nuclear medicine. The image is created by physically moving a radiation detector over the surface of a radioactive patient. It has become obsolete in ...
. Gordon Brownell developed the first
positron scanner. In the same decade (1954) the
Society of Nuclear Medicine (SNM) was organized in Spokane, Washington (US), and (1958)
Hal Anger
Hal Oscar Anger (May 20, 1920 – October 31, 2005) was an American electrical engineer and biophysicist at Donner Laboratory, University of California, Berkeley, known for his invention of the gamma camera.
In all, Anger held 15 patents, many of ...
developed the
gamma scintillation camera, which could image a whole region at the same time.
Initial introduction of radioisotopes into medicine required individuals to acquire of a considerable background information which was foreign to their medical training. Often a particular application drove the introduction of radioisotopes into a health care facility. As other applications developed the physician or group that had developed knowledge of and experience with radioisotopes usually provided the new service. Consequently, the radioisotope service found homes in several established specialties – commonly in radiology due to an interest in imaging, in pathology (
clinical pathology
Clinical pathology is a medical specialty that is concerned with the diagnosis of disease based on the laboratory analysis of bodily fluids, such as blood, urine, and tissue homogenates or extracts using the tools of chemistry, microbiology, ...
) due to an interest in radioimmunoassay, and in endocrinology due to the early application of
131I to thyroid disease.
Nuclear medicine became widespread and there was a need to develop a new specialty. In the United States, the
American Board of Nuclear Medicine
The American Board of Nuclear Medicine (ABNM) certifies physicians as specialists in the practice of nuclear medicine. Diplomates of the ABNM are called nuclear medicine physicians. The ABNM is one of the 24 member boards of the American Board ...
was formed in 1972. At that time, the specialty include all of the uses of radioisotopes in medicine – radioimmunoassay, diagnostic imaging, and therapy. As use of and experience with radioisotopes became more widespread in medicine, radioimmunoassay generally transferred from nuclear medicine to clinical pathology. Today, nuclear medicine is based on the use of the
tracer principle applied to diagnostic imaging and therapy.
Practice
Procedures
* Examples of the most common clinical nuclear medicine procedures are
** glucose metabolic imaging with
18F-
fluorodeoxyglucose
18F.html" ;"title="sup>18F">sup>18Fluorodeoxyglucose ( INN), or fluorodeoxyglucose F 18 (USAN and USP), also commonly called fluorodeoxyglucose and abbreviated 18F.html" ;"title="sup>18F">sup>18FDG, 2- 18F.html" ;"title="sup>18F">sup>18FDG or ...
(FDG) for cancer,
** myocardial perfusion imaging for
coronary artery disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pla ...
, and
** skeletal imaging for both benign and malignant bone disease.
* Examples of common procedures are
** brain perfusion and glucose metabolic imaging for
seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...
and
dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
,
** blood pool imaging for myocardial function and
gastrointestinal bleeding
Gastrointestinal bleeding (GI bleed), also called gastrointestinal hemorrhage (GIB), is all forms of bleeding in the gastrointestinal tract, from the mouth to the rectum. When there is significant blood loss over a short time, symptoms may incl ...
,
** gastric emptying studies for
gastroparesis
Gastroparesis (gastro- from Ancient Greek γαστήρ – gaster, "stomach"; and -paresis, πάρεσις – "partial paralysis"), also called delayed gastric emptying, is a medical disorder consisting of weak muscular contractions (peristalsis) ...
,
** hepatobiliary imaging for acute
cholecystitis
Cholecystitis is inflammation of the gallbladder. Symptoms include right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks (biliary colic) precede acute cholecystitis. The pain l ...
and gallbladder dysfunction,
** lymphoscintigraphy for
sentinel lymph node
The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasiz ...
biopsy,
** parathyroid imaging for
hyperparathyroidism
Hyperparathyroidism is an increase in parathyroid hormone (PTH) levels in the blood. This occurs from a disorder either within the parathyroid glands (primary hyperparathyroidism) or as response to external stimuli (secondary hyperparathyroidism). ...
,
** pulmonary perfusion and ventilation imaging for
pulmonary embolism
Pulmonary embolism (PE) is a blockage of an pulmonary artery, artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include dyspnea, shortness of breath, chest pain p ...
,
** renal function imaging for various
renal disorders,
** thyroid imaging for
hyperthyroidism
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism ...
,
** thyroid whole body imaging for
thyroid cancer
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck. C ...
,
** urinary tract imaging for
vesicoureteral reflux
Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into one or both ureters and then to the renal calyx or kidneys. Urine normally travels in one directi ...
, and
** white blood cell studies for infection.
* Examples of uncommon but valuable procedures are
**
octreotide
Octreotide, sold under the brand name Sandostatin among others, is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone. It was ...
(pentetreotide) or NETSPOT (gallium 68) imaging for
somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-couple ...
receptors found on the surface of many tumors,
**
meta-iodobenzylguanidine (
MIBG
Iobenguane, or MIBG, is an aralkylguanidine analog of the adrenergic neurotransmitter norepinephrine (noradrenaline), typically used as a radiopharmaceutical. It acts as a blocking agent for adrenergic neurons. When radiolabeled, it can be used ...
) imaging for
neuroendocrine tumors
Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the pancreas, lun ...
,
** heat-damaged red blood cell imaging for identifying ectopic splenic tissue, and
** gastric mucosa imaging for
Meckel's diverticulum
A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk). It is the most common malformat ...
(especially in pediatrics).
* Examples of radionuclide therapeutic procedures are
**
131I treatment of
hyperthyroidism
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism ...
,
**
131I treatment of
thyroid cancer
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck. C ...
, and
**
radioimmunotherapy
Radioimmunotherapy (RIT) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target cell. It is a form of unsealed source radiotherapy. In cancer therapy, an antibody with specificity for a tumor-associated antigen i ...
with
90Y
ibritumomab tiuxetan
Ibritumomab tiuxetan (pronounced ), sold under the trade name Zevalin, is a monoclonal antibody radioimmunotherapy treatment for non-Hodgkin's lymphoma. The drug uses the monoclonal mouse IgG1 antibody ibritumomab in conjunction with the chelator ...
(Zevalin) &
131I
tositumomab
Tositumomab is a murine monoclonal antibody which targets the CD20 antigen produced in mammalian cell. It was combined with iodine-131 to produce a radiopharmaceutical for unsealed source radiotherapy, Iodine-131 Tositumomab (branded as Bexxar), fo ...
(Bexxar) therapy of low-grade non-Hodgkin's lymphoma.
**
188Re (
Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one ...
) as Rhenium-SCT for treatment of
Non-Melanoma Skin Cancer
Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types of skin cancers: basal-cell skin cancer (BCC ...
(
basal cell carcinoma
Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raise ...
or
squamous cell carcinoma
Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the ...
)
Instrumentation
* Planar imaging
:Most radionuclides give off
gamma-ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nucleus, atomic nuclei. It consists of the shortest wavelength electromagnetic wav ...
s when they decay. A 2-dimensional image of the radionuclide distribution can be made with a
gamma camera
A gamma camera (γ-camera), also called a scintillation camera or Anger camera, is a device used to image gamma radiation emitting radioisotopes, a technique known as scintigraphy. The applications of scintigraphy include early drug development ...
, often called an Anger scintillation camera after its inventor,
Hal Anger
Hal Oscar Anger (May 20, 1920 – October 31, 2005) was an American electrical engineer and biophysicist at Donner Laboratory, University of California, Berkeley, known for his invention of the gamma camera.
In all, Anger held 15 patents, many of ...
.
*
Single photon emission computed tomography
Single-photon emission computed tomography (SPECT, or less commonly, SPET) is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera (that is, ...
(
SPECT
Single-photon emission computed tomography (SPECT, or less commonly, SPET) is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera (that is, ...
)
:Multiple planar images taken from different angles around a patient can be
reconstructed to form a stack of cross-sectional, tomographic images.
*
Positron emission tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including bl ...
(PET)
:Some isotopes emit
positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides ...
s (the anti-matter equivalent of an electron) when they decay. The positrons travel a short distance in tissue and then annihilate with an electron giving off two nearly back-to-back gamma rays. Positron emission tomography takes advantage of these back-to-back gamma rays to localize the distribution of the radioisotopes.
* Combined molecular and anatomic imaging:
SPECT/CT,
PET/CT
Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a nuclear medicine technique which combines, in a single gantry, a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner ...
, and
PET/MRI
:The advantage of nuclear medicine is that it provides molecular and physiologic information, but it is relatively poor at providing anatomic information and the resolution is relatively poor. In recent years, instruments have been developed which allow both radioisotope and anatomic imaging. Most widespread are PET/CT scanners combining PET and computed tomography. Increasingly common are SPECT/CT scanners. Instruments combining PET with magnetic resonance, PET/MRI, are starting to be used.
* Non-imaging instrumentation
:Non-imaging instruments are used for measuring
radioisotope doses, for counting samples, for measuring thyroid uptake of radioiodine, for measuring sentinel lymph node uptake during
mastectomy
Mastectomy is the medical term for the surgical removal of one or both breasts, partially or completely. A mastectomy is usually carried out to treat breast cancer. In some cases, women believed to be at high risk of breast cancer have the operat ...
procedures to and for
radiation safety
Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Expos ...
.
Training
In the United States, the
Accreditation Council for Graduate Medical Education
The Accreditation Council for Graduate Medical Education (ACGME) is the body responsible for accrediting all graduate medical training programs (i.e., internships, residencies, and fellowships, a.k.a. subspecialty programs) for physicians in the ...
(ACGME) and the
(AOABOS) accredit nuclear medicine residency programs, and the
American Board of Nuclear Medicine
The American Board of Nuclear Medicine (ABNM) certifies physicians as specialists in the practice of nuclear medicine. Diplomates of the ABNM are called nuclear medicine physicians. The ABNM is one of the 24 member boards of the American Board ...
(ABNM) and the
American Osteopathic Board of Nuclear Medicine (AOBNM) certify nuclear medicine physicians. After completing
medical school
A medical school is a tertiary educational institution, or part of such an institution, that teaches medicine, and awards a professional degree for physicians. Such medical degrees include the Bachelor of Medicine, Bachelor of Surgery (MBBS, M ...
, a post-graduate
clinical year is followed by three years of nuclear medicine
residency
Residency may refer to:
* Domicile (law), the act of establishing or maintaining a residence in a given place
** Permanent residency, indefinite residence within a country despite not having citizenship
* Residency (medicine), a stage of postgrad ...
. A common alternate path for physicians who have completed a radiology residency is a one-year residency in nuclear medicine, leading to sub-specialty certification by the American Board of Radiology. A less common path for physicians who have completed another residency is a two-year residency in nuclear medicine.
Other professionals
Nuclear medicine procedures are performed by
Nuclear Medicine Radiographers,
nuclear medicine technologists
/ref> who require extensive training both in underlying principles (physics, instrumentation) but also in the clinical applications. Nursing
Nursing is a profession within the health care sector focused on the care of individuals, families, and communities so they may attain, maintain, or recover optimal health and quality of life. Nurses may be differentiated from other health ...
support, especially in the hospital setting, is valuable, but may be shared with other services. Nuclear medicine is a technology embedded specialty depending upon a large number of non-physician professional, including medical physicists
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pr ...
, health physicists
Health, according to the World Health Organization, is "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity".World Health Organization. (2006)''Constitution of the World Health Organiza ...
, radiobiologists, radiochemists, and radiopharmacists.
Residency trained nuclear medicine physicians have the most extensive training and highest level of certification, including all aspects of diagnosis and radionuclide therapy. However, current U.S. regulations do not prohibit other physicians from interpreting nuclear medicine studies and perform radionuclide therapy. Radiologists
Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiatio ...
who are not sub-specialty trained in the specialty, nonetheless often limit their practice to practicing nuclear medicine. Some cardiologists
Cardiology () is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart d ...
, especially non-invasive cardiologists, will interpret diagnostic cardiology studies including nuclear medicine studies. Radiation oncologists
A radiation oncologist is a specialist physician who uses ionizing radiation (such as megavoltage X-rays or radionuclides) in the treatment of cancer. Radiation oncology is one of the three primary specialties, the other two being surgical and me ...
perform all forms of radiation therapy, sometimes including radionuclide therapy. Some endocrinologist
Endocrinology (from ''endocrine'' + '' -ology'') is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events ...
s treat hyperthyroidism and thyroid cancer with 131I. The mix of physicians rendering nuclear medicine services varies both between different countries and within a single country.
See also
* Radiographer
Radiographers, also known as radiologic technologists, diagnostic radiographers and medical radiation technologists are healthcare professionals who specialize in the imaging of human anatomy for the diagnosis and treatment of pathology. Radi ...
References
External links
American Board of Nuclear Medicine
American Osteopathic Board of Nuclear Medicine
American Board of Medical Specialties
International Atomic Energy Agency (IAEA), Division of Human Health, Nuclear Medicine
Society of Nuclear Medicine and Molecular Imaging
formerly the Society of Nuclear Medicine (SNM)
*
About nuclear medicine
*
List of nuclear medicine societies
{{DEFAULTSORT:Nuclear Medicine Physician
Nuclear medicine