{"entity":{"id":"gamma-probes-dose-calibrators","kind":"technology","name":"Gamma probes, handheld gamma cameras and dose calibrators","aka":[],"tldr":"The small radiation detectors that make nuclear medicine and sentinel node surgery work: a pen-sized probe that clicks when the surgeon nears the radioactive lymph node, and the well counter in the hot lab that checks every dose before it is injected.","summary":"Sentinel lymph node biopsy replaced full node clearance in breast cancer and melanoma because the surgeon can find the node with a handheld gamma probe: a collimated scintillation or semiconductor detector that counts the technetium-99m nanocolloid injected around the tumour, guiding the incision and confirming when the hot nodes are out. Devicor's Neoprobe (now under Mammotome), Eurorad's Europrobe, Crystal Photonics' CrystalProbe and drop-in probes for robotic surgery from Lightpoint Medical are the main devices; small handheld gamma cameras such as Sentinella and Crystal Cam image the node field, and PET-emitting tracers such as gallium-68 PSMA are detected with high-energy probes in radioguided prostate surgery. Magnetic tracers detected by Endomag's Sentimag (also now part of Mammotome) offer the same localisation without radioactivity. In the radiopharmacy and hot lab, dose calibrators, ionisation well chambers such as Capintec's CRC series (Mirion) and Comecer's, measure the activity of every syringe of diagnostic tracer or therapeutic radioligand against the prescription, and survey meters and contamination monitors protect staff.\n\nThe probe technique needs a nuclear medicine department to inject and image the tracer, a supply of technetium-99m from molybdenum generators, and radiation-protection handling of specimens; magnetic and fluorescent alternatives remove the isotope but have their own artefacts. Dose calibrators are inexpensive but require regular constancy, linearity and geometry checks and isotope-specific calibration factors, especially for the new alpha and beta therapy isotopes.","status":"standard-of-care","asOf":"2026-09-17","links":[{"label":"Wikipedia: sentinel lymph node","url":"https://en.wikipedia.org/wiki/Sentinel_lymph_node"},{"label":"Mammotome: Neoprobe gamma detection system","url":"https://www.mammotome.com/"},{"label":"IAEA: quality assurance for radioactivity measurement in nuclear medicine (Technical Reports Series 454)","url":"https://www.iaea.org/publications/7451/quality-assurance-for-radioactivity-measurement-in-nuclear-medicine"}],"tags":["machines-wave2"],"related":["intraoperative-fluorescence-imaging-systems","medical-cyclotrons-synthesis-modules","radioligand-dosimetry"],"cancers":["breast-cancer","melanoma","prostate","merkel-cell-carcinoma","vulvar","head-and-neck","endometrial"],"sections":["surgery","radiopharma","devices"],"technologies":["sentinel-node","spect-ct","radioligand-therapy","psma-pet","radiopharmacy-network"],"targets":[],"drugs":[],"companies":["mammotome","lightpoint-medical","sun-nuclear","comecer"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Collimated scintillation or cadmium zinc telluride detectors count gamma photons from a tracer in the sentinel node to guide surgical localisation; pressurised ionisation well chambers measure the activity of radiopharmaceutical doses by ionisation current with isotope-specific calibration factors.","strengths":["Enables sentinel node surgery and radioguided resection","Every dose measured before injection","Cheap and widely available"],"limitations":["Depends on isotope supply and a nuclear medicine department","Radiation protection of theatre and pathology staff","Calibration factors needed for new therapy isotopes"],"since":1990},"route":"/technologies/gamma-probes-dose-calibrators/","neighbours":{"technology":[{"id":"intraoperative-fluorescence-imaging-systems","kind":"technology","name":"Intraoperative fluorescence and Cerenkov imaging systems (SPY, Firefly, LumiSystem, LightPath)","route":"/technologies/intraoperative-fluorescence-imaging-systems/"},{"id":"medical-cyclotrons-synthesis-modules","kind":"technology","name":"Medical cyclotrons, hot cells, and synthesis modules","route":"/technologies/medical-cyclotrons-synthesis-modules/"},{"id":"psma-pet","kind":"technology","name":"PSMA PET","route":"/technologies/psma-pet/"},{"id":"radioligand-dosimetry","kind":"technology","name":"Radioligand dosimetry","route":"/technologies/radioligand-dosimetry/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"},{"id":"radiopharmacy-network","kind":"technology","name":"Radiopharmacy and cyclotron networks","route":"/technologies/radiopharmacy-network/"},{"id":"sentinel-node","kind":"technology","name":"Sentinel lymph node biopsy","route":"/technologies/sentinel-node/"},{"id":"spect-ct","kind":"technology","name":"SPECT/CT","route":"/technologies/spect-ct/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"endometrial","kind":"cancer","name":"Endometrial cancer","route":"/cancers/endometrial/"},{"id":"head-and-neck","kind":"cancer","name":"Head and neck squamous cell carcinoma","route":"/cancers/head-and-neck/"},{"id":"melanoma","kind":"cancer","name":"Melanoma","route":"/cancers/melanoma/"},{"id":"merkel-cell-carcinoma","kind":"cancer","name":"Merkel cell carcinoma","route":"/cancers/merkel-cell-carcinoma/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"vulvar","kind":"cancer","name":"Vulvar cancer","route":"/cancers/vulvar/"}],"section":[{"id":"devices","kind":"section","name":"Devices & Physical Therapies","route":"/fronts/devices/"},{"id":"radiopharma","kind":"section","name":"Radiopharmaceuticals & Theranostics","route":"/fronts/radiopharma/"},{"id":"surgery","kind":"section","name":"Surgery & Interventional","route":"/fronts/surgery/"}],"company":[{"id":"comecer","kind":"company","name":"Comecer (ATS)","route":"/companies/comecer/"},{"id":"lightpoint-medical","kind":"company","name":"Lightpoint Medical","route":"/companies/lightpoint-medical/"},{"id":"mammotome","kind":"company","name":"Mammotome (Danaher)","route":"/companies/mammotome/"},{"id":"sun-nuclear","kind":"company","name":"Sun Nuclear (Mirion)","route":"/companies/sun-nuclear/"}]}}