99mTc internal contaminations measurements among nuclear medicine medical personnel during ventilation - perfusion SPECT lung scans

This paper presents results of measurements of ^99mTc activity concentration in air and nuclear medical personnel blood during ventilation-perfusion SPECT lung scans. ^99mTc activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow. Technicians and nurses who perform examinations were equipped with personal aspirators enabling air sampling to determine the radiation exposure at their workplaces. Measurements allowed to evaluate the concentration of ^99mTc in 14 air samples and it ranged from 7800 ± 600 to 10,000 ± 1000 Bq m^-3 for air samples collected by technicians and from 390 ± 30 to 600 ± 40 Bq m^-3 for air samples collected by nurses. In addition ^99mTc concentrations in blood of medical personnel were determined in 24 samples. For technicians the maximum ^99mTc blood concentration levels reached 920 ± 70 Bq L^-1 and 1300 ± 100 Bq L^-1. In the case of nurses, the maximum estimated activity concentrations were about ten times lower, namely 71 ± 7 Bq L^-1 and 39 ± 3 Bq L^-1. Although the intakes appear to be relatively high, the resulting annual effective doses are about 34 µSv for technicians and only 2 µSv for nurses.

Radiochemical separation of no-carrier-added 177Lu as produced via the 176Yb(n,gamma)177Yb-->177Lu process

The 176Yb(n,gamma)177Yb-beta(-)-->177Lu process was investigated to provide no-carrier-added (nca) 177Lu. The radiochemical separation of the 177Lu from the macro-amounts of the ytterbium target based on the cementation process, i.e. the selective extraction of Yb by Na(Hg) amalgam from Cl-/CH3COO- electrolytes, followed by a final cation exchange purification. The cementation separation process provides a decontamination factor of Yb(III) of 10(4), the cation exchange purification adding a decontamination factor of > 10(2). The nca 177Lu is available in radiochemically pure form despite the chemical similarity of the lanthanides with 75 +/- 5% overall separation yield within 4-5 h. It can be used to synthesise nca 177Lu labelled radiotherapeuticals.