Hello, My name is Veronica Garea. I am a Nuclear Engineer by training (ME, PhD) and a volunteer peer breastfeeding counselor in Bariloche, Argentina. I have re-subscribed to Lactnet after a two-year absence and have been a most active lurker. Tc Mebrofenin is one of the radiopharmaceuticals produced with the radioisotope Tc. Different purposes require different radiopharmaceuticals. Tc99m (the isotope used in nuclear medicine) has a half life of 6 hours. The International Radiation Protection Commission (international organization that establishes radiation protection guidelines for medicine, nuclear industry and others) states the following (see Nuclear Medicine and Pregnancy, in www.icrp.org): --begin quote--------------------- A number of radionuclides are excreted in breast milk. It is recommended that breast feeding is suspended as follows: [...] 12 h after 131I hippurate and all 99mTc compounds except as below 4 h after 99mTc red cells, DTPA, and phosphonates --end quote------------------------- Therefore, suggesting pumping for 12 hours is in accordance with ICRP guidelines. Storing milk and using after at least 12 hours is also reasonable (since half life is 6 hours, in 12 hours the Tc99m has practically dissapeared from the milk). Regards, Veronica Garea Grupo de Apoyo a la Lactancia Materna de Bariloche *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(R) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html