Maz, yep if your having sentinel node mapping they will inject a radioactive dye under your nipple, then wait about 10 minutes and then try scanning you to see how far the dye has moved. You may need to massage your breast to get the dye moving. All up my mapping took about an hour and a half and some of that was waiting for the doctor to travel from another suburb (original machine I was supposed to go to broke down that day). Sounds pretty horrific but its more like a nipple cripple (pressure). I felt that the doctor was pulling my nipple up and away from my chest. Its nowhere near as bad as it sounds. And I had my bone scans done at the same time - all good! Let us know when you have your date for this. Xx Cath