Effects in the testes after SPECT myocardial perfusion with Tl-201 or Tc-99m hexaMIBI.
Thallium-201 with a half-life of 73 hours, decays by electron capture and as a consequence emits numerous Auger electrons. When it localises in the cell nucleus it causes enhanced biological effects. Technetium-99m with a half-life of 6 hours, radiates gamma rays and the side effects are not as significant. Tl-201 and Tc-99m labelled with SESTAMIBI are used for the SPECT perfusion image of the heart. In this study the tissue of interest are the testes which, after irradiation, can develop stochastic effects: both somatic (cancer) and hereditary. The activities of the radiopharmaceuticals used in common practice (30 mCi of Tc-99m and 3 mCi of Tl-201) cause different probabilities for the induction of stochastic effects in the testes. The probabilities are about 30 times higher for Tl-201 than for Tc-99m. These results, in combination with the fact that the higher activity of Tc-99m yields better images within shorter time, must make the clinician carefully assess the choice of the radiopharmaceutical to be used for the studies of the heart, especially for patients of reproductive age.
Manetou
A
A
Medical Physics Unit, NIMTS Hospital, Athens, Greece.
Limouris
G S
GS
D006207:Half-Life; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics*; D013736:Testicular Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D013737:Testis / Q000528:radiation effects*; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi