Presentation on theme: "Radioactive seed localisation"— Presentation transcript:
1Radioactive seed localisation Mr Paul SamsonBreast and General SurgeonNZIMRT National Training Day, InvercargillAugust 2014
2Problems with WiresScheduling conflicts between radiology and surgery due to need for multiple procedures on day of surgeryInability to use wire localization for first theatre case in the morningWire displacement or transectionWire entry site and wire tip often well removed from target lesion -> non-uniform specimen resultsSurgeon often unable to confirm exact site of lesion
3Radioactive seed-localized lumpectomy Titanium seed containing 3.7 to 10.7 MBq 125I which has half life of 60 days and emits 27 keV of gamma radiationTechnicium-99 has shorter half-life (6 hours) but stronger gamma emission of 140 keV.Tip of 18G needle occluded with bone wax, seed is loaded, and a stilette loosely placed into the needleUSA protocols have seed placed within 5 days of surgerySeed is introduced under USS or MMG guidance. Angle of radiologists approach not limited.
6Radioactive seed-localized lumpectomy Standard intra-op handheld gamma probe to localize the seed (settings 125I for seed or 99Tc for sentinel node)Incise directly over the lesionGamma probe to guide resection with margin and confirm excision of lesion plus seedSpecimen radiograph taken (optional)Seed removed by pathology and returned to nuclear medicine
11MSKCC Breast Seed Localization The items you touch, people you encounter, and clothes that you wear will not become radioactive.People who are in close physical contact with you may be exposed to very small amounts of radiation. While there is no evidence that this exposure causes harm, there are things you can do to minimize radiation exposure to others:Distance. The amount of radiation emitted from your body is very small. It decreases significantly at a distance of 1 foot from the implant site. There is almost no radiation reaching a distance of 3 feet away.Time. Radiation exposure to others depends on how long you remain in close contact with them. You will not harm anyone by hugging, kissing, or shaking hands. You should avoid placing an infant, child, or young animal on your chest for any longer than 30 minutes per day for the next month (30 days) or until the seed is removed during surgery.