technetium-tc-99m-exametazime and thallium-chloride

Sequential thallium-201-chloride and technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) images were obtained in a patient with extracranial metastatic glioblastoma multiforme. Thallium-201 uptake was high (three times the scalp background) in all pathologically confirmed extracranial metastases and moderate (1.6 times scalp background) intracranially, where most biopsy specimens showed gliosis with scattered atypical astrocytes. Technetium-99m-HMPAO uptake was decreased intracranially in the right frontal and parietal lobes which had been irradiated. It was also decreased in one well-encapsulated scalp lesion and high in another scalp mass with less defined borders. Possible mechanisms of tumor uptake of these agents are reviewed.

Topics: Adult; Brain Neoplasms; Female; Glioblastoma; Humans; Organotechnetium Compounds; Oximes; Scalp; Skin Neoplasms; Technetium Tc 99m Exametazime; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon

The uptake, retention and uptake antagonism of 201Tl-DDC, 201Tl-Cl, 123I-IMP, 99mTc-HMPAO and 99mTc-O4- were compared in rat neocortex cultures. 201Tl-DDC and 123I-IMP revealed the highest uptake of radioactivity in the cultures. 99mTc-HMPAO and 123I-IMP showed the highest retention of radioactivity within the tissue in washout experiments. Blocking of bioelectric activity by tetrodotoxin did not significantly affect the uptake of the radiopharmaceuticals (RPHA). Inhibition of Na-K-ATPase by ouabain inhibited the uptake of 201Tl-Cl (77%) and 201Tl-DDC (27%). Imipramine showed a significantly stronger inhibitory effect on 123I-IMP uptake in comparison with the effect on other RPHA. 99mTc-O4- was not concentrated within the cultured tissue. Under the in vitro conditions used in this study, the various RPHA were characterised by distinct differences in their interaction with cortical brain tissue.

Topics: Amphetamines; Animals; Cerebral Cortex; Ditiocarb; Imipramine; In Vitro Techniques; Iodine Radioisotopes; Iofetamine; Organometallic Compounds; Ouabain; Oximes; Rats; Rats, Inbred Strains; Sodium Pertechnetate Tc 99m; Technetium; Technetium Tc 99m Exametazime; Tetrodotoxin; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed