A gamma probe is a handheld device containing a
scintillation counter
A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillating material, and detecting the resultant light pulses.
It consists of a scintillator w ...
, for
intraoperative use following
injection
Injection or injected may refer to:
Science and technology
* Injective function, a mathematical function mapping distinct arguments to distinct values
* Injection (medicine), insertion of liquid into the body with a syringe
* Injection, in broadca ...
of a
radionuclide
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; transfer ...
, to locate
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 ...
s by their radioactivity. It is used primarily for sentinel lymph node mapping and
parathyroid
Parathyroid glands are small endocrine glands in the neck of humans and other tetrapods. Humans usually have four parathyroid glands, located on the back of the thyroid gland in variable locations. The parathyroid gland produces and secretes par ...
surgery. Gamma probes are also used for RSL (radioactive seed localization), to locate small and non-
palpable
Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...
breast
lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals.
Types
There is no designated classifi ...
s.
History
The sentinel node market experienced high growth in the early and mid 1990s starting with melanoma sentinel node surgical search and breast cancer sentinel node staging; both are currently considered standards of care. The use of a radioactive tracer, rather than a coloured dye, was proposed in 1984.
Clinical use
To locate the draining lymph nodes or sentinel lymph node from a breast cancer tumour a
Technetium-99m
Technetium-99m (99mTc) is a metastable nuclear isomer of technetium-99 (itself an isotope of technetium), symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical ra ...
based
radiopharmaceutical
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 ...
is common. This may be a nanocolloid or
sestamibi
Technetium (99mTc) sestamibi (INN) (commonly sestamibi; USP: technetium Tc 99m sestamibi; trade name Cardiolite) is a pharmaceutical agent used in nuclear medicine imaging. The drug is a coordination complex consisting of the radioisotope techn ...
. Although imaging 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 ...
may also take place, the idea of a small gamma probe is that it can be used to identify lymph nodes (or other sites) with uptake at a much higher resolution, during an operation. The probe may be collimated to further restrict the field of detection.
See also
*
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 ...
*
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 h ...
References
External links
Video on SLNVideo on Sentinel Node Mapping in Melanoma
{{DEFAULTSORT:Gamma Probe
Nuclear medicine
Image sensors
Medical physics
American inventions