Radiation doses deriving from patients undergoing 111In-DTPA-D-phe-1-octreotide scintigraphy

The purpose of this study was to estimate the radiation doses to nursing staff, other patients, accompanying persons and family members deriving from patients undergoing 111In-DTPA-d-Phe-1-octreotide (111In-OCT) scintigraphy. Dose rates were measured from 16 patients who had received an intravenous injection of 140+/-40 MBq 111In-OCT. The measurements were performed at three different distances (0.5, 1 and 2 m) at 10-20 min, 5-7 h and 24 h (and in some cases, up to 48 h) after administration of 111In-OCT. The effective half-lives of the biexponential decrease of the dose rates were estimated to be 2.94+/-0.27 h (T1) and 65.17+/-0. 58 h (T2). The calculated maximum dose to other persons in the waiting area was 27.2 microSv, to family members 61.5 microSv, to nursing staff in a ward 24.1 microSv and to neighbouring patients in the ward 69.5 microSv. Our results clearly demonstrate that the calculated maximum radiation exposure to accompanying persons, personnel, family members and other patients is well below the maximum annual dose limit for non-professionally exposed persons.