Gamma probe

A gamma probe is a handheld device containing a scintillation counter for intraoperative use following injection of a radionuclide to locate sentinel lymph nodes by their radioactivity.^[1] It is used primarily for sentinel lymph node mapping and parathyroid surgery. Gamma probes are also used for RSL (radioactive seed localization) to locate small and non-palpable breast lesions.^{[2][3]: 243}

Gamma probe
A gamma probe
Purpose	locate sentinel lymph nodes

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.^[4] The use of a radioactive tracer, rather than a coloured dye, was proposed in 1984.^[5][6]

Clinical use

To locate the draining lymph nodes or sentinel lymph nodes from a breast cancer tumour, a Technetium-99m based radiopharmaceutical is common. This may be a nanocolloid or sestamibi.^[7] Although imaging with a gamma camera 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 restrict the field of detection further.^[8][9]

See also

• Nuclear medicine
• Molecular Imaging