Comparison of the radiotoxicity of the 99mTc-labeled compounds 99mTc-pertechnetate, 99mTc-HMPAO and 99mTc-MIBI.
Int J Radiat Biol
; 92(11): 698-706, 2016 11.
Article
em En
| MEDLINE
| ID: mdl-27117205
ABSTRACT
PURPOSE:
In addition to gamma radiation, 99mTc emits low-energy Auger electrons with path-lengths of nanometers to micrometers that cannot be utilized for diagnostic procedures; however, they have frequently been discussed for therapeutic applications. We compared radiotoxicity of three 99mTc-labeled radiopharmaceuticals with differences in the subcellular distribution. MATERIALS ANDMETHODS:
The intracellular radionuclide uptake and subcellular distribution of [99mTc]-pertechnetate (99mTc-pertechnetate), [99mTc]Tc-hexamethyl-propylene-aminoxime (99mTc-HMPAO) and [99mTc]Tc-hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) were quantified in rat thyroid FRTL-5 cells. Radiotoxicity was compared using late phosphorylated histone H2AX (γH2AX) foci as a marker for unrepaired DNA double-strand breaks (DNA-DSB) and clonogenic cell survival.RESULTS:
99mTc-HMPAO showed a substantially higher uptake into the nucleus and the membrane/organelles than 99mTc-pertechnetate or 99mTc-MIBI. The colony-forming assay showed that 99mTc-pertechnetate and 99mTc-HMPAO caused a similar reduction in cell survival. 99mTc-MIBI is less radiotoxic in terms of the estimated nucleus dose and induced the fewest number of γH2AX foci compared with the other 99mTc-tracers, and 99mTc-HMPAO induced a fewer number of γH2AX foci than 99mTc-pertechnetate.CONCLUSIONS:
Our findings reveal that clonogenic cellular survival is not solely determined by the DNA-DSB response. This finding may suggest the involvement of extra-nuclear radiosensitive targets in cell inactivation. For example, the mitochondria or the cell membrane could be affected by 99mTc-HMPAO.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Glândula Tireoide
/
Compostos de Tecnécio
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article