Are MIBI/tetrofosmin heart studies a potential radiation hazard to technologists?
The number of nuclear medicine studies is increasing and they are becoming more complex and time-consuming. In particular, this is true of myocardial perfusion investigations. We use a one-day protocol for these studies, utilizing 99Tc(m)-MIBI or 99Tc(m)-tetrofosmin with tomographic rest images (250 MBq) acquired in the morning and exercise images (750 MBq) approximately 4 h later after pharmacological stress. Imaging technologists are concerned about continual exposure to 1000 MBq 99Tc(m) per study. Radiation doses were measured during rest (1.0 microSv, n = 18), exercise (2.5 microSv, n = 18) and stress administration (2.0 microSv, n = 16), giving a total dose of 5.5 microSv per combined cardiac study. We have previously shown that the average dose per radionuclide study (excluding myocardial perfusion studies) is 1.5 microSv. Although 5.5 microSv is higher, a technologist is highly unlikely to exceed current dose limits. New EC legislation, however, is expected to reduce these limits, which may lead to more classified workers. Pregnant technologists should avoid, if possible, combined cardiac studies, especially if performing other nuclear medicine duties.
Clarke
E A
EA
Department of Physics and Nuclear Medicine, City Hospital NHS Trust, Birmingham, UK.
Notghi
A
A
Harding
L K
LK
D000241:Adenosine; D000318:Adrenergic beta-Agonists; D000488:Allied Health Personnel; D004280:Dobutamine; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D009683:Nuclear Medicine; D016273:Occupational Exposure; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011247:Pregnancy; D011829:Radiation Dosage; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013312:Stress, Physiological; D017256:Technetium Tc 99m Sestamibi
D000318:Adrenergic beta-Agonists; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D004280:Dobutamine; C078700:technetium tc-99m tetrofosmin; D017256:Technetium Tc 99m Sestamibi; D000241:Adenosine