Radioactive seed localisation

Mr Paul SamsonBreast and General Surgeon

NZIMRT National Training Day, InvercargillAugust 2014

Problems with Wires

Scheduling conflicts between radiology

and surgery due to need for multiple

procedures on day of surgery

Inability to use wire localization for first

theatre case in the morning

Wire displacement or transection

Wire entry site and wire tip often well

removed from target lesion -> non-uniform

specimen results

Surgeon often unable to confirm exact site

of lesion

Radioactive 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

radiation

Technicium-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 needle

USA protocols have seed placed within 5 days of surgery

Seed is introduced under USS or MMG guidance.

Angle of radiologists approach not limited.

Radioactive 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 lesion

Gamma probe to guide resection with

margin and confirm excision of lesion plus

seed

Specimen radiograph taken (optional)

Seed removed by pathology and returned

to nuclear medicine

Radioactive seed localisation

Mayo Clinic technique

Better cosmesis, no wire dislodgement worries, more comfortable for patient, easier scheduling of surgery

Rapid learning curve, improved cosmesis

No large multicentre trial, billing issues, radioactive substance regulations

Radioactive seed localisation.

The end of Hookwires?

MSKCC 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.