Ion transport systems in the uptake of 99Tcm-tetrofosmin, 99Tcm-MIBI and 201T1 in a tumour cell line

As, Arbab; Koizumi, Kiyoshi; Toyama, Keiji; Arai, Takao; Araki, Tsutomu

doi:10.1097/00006231-199703000-00007

Cited by 38 publications

(14 citation statements)

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“…La scintigraphie au MIBI-Tc 99m est la méthode la plus sensible pour localiser les LP [20][21]. Le MIBI, cation monovalent lipophile, est capté par diffusion passive transmembranaire et s'accumule préférentiellement dans les mitochondries [3]. La captation du MIBI par les cellules parathyroïdiennes est néanmoins variable et dépend de nombreux facteurs parmi lesquels la vascularisation, l'activité métabolique ou la richesse en mitochondries des cellules oxyphiles [4,[22][23].…”

Section: Discussionunclassified

“…L'imagerie scintigraphique (au La sensibilité de l'échographie varie selon la taille et la localisation de la glande hyperfonctionnelle (mauvaise détection des lésions ectopiques médiastinales) [1]. La sensibilité de la scintigraphie au MIBI dépend surtout de la richesse en mitochondries, de la densité en cellules oxyphiles et de la nature solide ou kystique de la glande [3][4]. Depuis quelques années, la tendance est d'opérer plus précocement les patients avec une amélioration significative de la qualité de vie [5].…”

Section: Introductionunclassified

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Tomographie sténopéïque au 99mTc-MIBI dans l’hyperparathyroïdie primaire

et al. 2007

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Amélioration de la détection des lésions par la tomographie sténopéïque au MIBI-Tc 99m dans l'hyperparathyroïdie primaire. Tc 99m -MIBI pinhole SPECT in primary hyperparathyroidism: improvement of parathyroid lesion detection.Oudoux A 1 , Carlier T 1 , Mirallié E 2 , Bodet-Milin C 1 , Seret A 3 , Defrise M 4 , Aubron F 5 , Daumy I 5 , Leux C 6 , Kraeber-Bodéré F 1 et Ansquer C 1 . Methods: Fifty one patients cured after surgery were studied. pSPECT was reconstructed with a dedicated OSEM algorithm. A diagnostic confidence score (CS) was assigned to each procedure considering intensity and extra-thyroidal location of suspected lesions and was defined as follows: 0 = negative, 1 = doubtful, 2 = moderately positive, 3 = positive.Results: Surgery revealed 55 lesions. Sensitivity of ultrasonography, planar imaging, cSPECT and pSPECT were respectively 51%, 76%, 82% and 87%. Five glands were only detected by pSPECT. Combination of ultrasonography, planar and pSPECT showed the highest sensitivity (94.5%). The mean CS of the 55 pathologic glands was significantly higher with pSPECT compared with planar imaging and cSPECT (p<0.0001). Compared with planar imaging and cSPECT, pSPECT increased CS for 42% and 53% of parathyroid lesions respectively, and contributed to markedly reduce the number of uncertain results.Nevertheless, planar imaging and ultrasonography were useful to analyze thyroid morphology and to detect some ectopic glands. Conclusion:The use of pSPECT increases sensitivity and CS of scintigraphy. Combination of ultrasonography, planar and pSPECT appears to be complementary and the optimal preoperative imaging procedure in primary hyperparathyroidism.

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Section: Discussionunclassified

Section: Introductionunclassified

Tomographie sténopéïque au 99mTc-MIBI dans l’hyperparathyroïdie primaire

et al. 2007

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“…The uptake mechanisms of 99m Tc-MIBI and 201 Tl differ [28,29,30]; consequently, the decrease in uptake of these tracers in hypoxic cells would be caused by the alteration of several cellular activities. 201 Tl uptake is related to cell membrane potential, Na + ,K + pump activity and Na + ,K + ,2Cl -co-transport [28].…”

Section: Discussionmentioning

confidence: 99%

“…201 Tl uptake is related to cell membrane potential, Na + ,K + pump activity and Na + ,K + ,2Cl -co-transport [28]. 99m Tc-MIBI uptake is mediated by the Na + ,K + pump and Na + ,H + antiport; however, passive diffusion through membranes also plays a major role [28,29]. 99m Tc-MIBI localizes inside mitochondria, whereas 201 Tl remains in the cytosolic compartment [28,29,30].…”

Section: Discussionmentioning

confidence: 99%

Hypoxia-induced alteration of tracer accumulation in cultured cancer cells and xenografts in mice: implications for pre-therapeutic prediction of treatment outcomes with 99mTc-sestamibi, 201Tl chloride and 99mTc-HL91

Kinuya

Yokoyama

et al. 2002

Eur J Nucl Med

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Weak visualization of tumours in pre-therapeutic scintigrams with technetium-99m sestamibi (MIBI) is likely a predictive sign of unfavourable tumour response to radiotherapy and chemotherapy. However, factors relating to this scintigraphic finding are not well understood. The presence of hypoxic tumour cells is one of the major reasons for therapeutic failure; consequently, we attempted to determine whether oxygenation status affects (99m)Tc-MIBI accumulation in tumour cells. LS180 human colon cancer and T24 human bladder cancer cells were incubated in air or N(2) gas at 37 degrees C. Cellular uptake of (99m)Tc-MIBI was subsequently determined at 15, 60 and 120 min. Uptake of thallium-201 chloride was also assessed. Uptake of (99m)Tc-HL91 was assessed as a hypoxic marker. Accumulation of the tracers in LS180 xenografts was observed in mice treated with 5 mg/kg hydralazine and compared with that in untreated mice. pO(2) in the medium and tumours was measured with O(2) microelectrodes. N(2) gas flow gradually reduced pO(2) in the cell suspension to 1-2 mmHg in 60 min. Cellular uptake of (99m)Tc-MIBI in LS180 cells decreased by approximately 30% in N(2) gas in comparison to that in air throughout the study. Hypoxia had a more prominent influence on (201)Tl uptake, which displayed a reduction of approximately 60% in N(2) gas at 120 min, than on (99m)Tc-MIBI uptake. On the other hand, N(2) gas induced an increase of 170% in (99m)Tc-HL91 uptake at 120 min, indicating the hypoxic condition of cells. The results of in vitro assays employing the T24 cell line were similar to those obtained with the LS180 cell line. Hydralazine treatment markedly reduced (99m)Tc-MIBI and (201)Tl accumulation in LS180 xenografts; moreover, intratumoural pO(2) decreased from 14.5 +/- 6.6 mmHg to 7.6 +/- 6.2 mmHg. (99m)Tc-HL91 accumulation in xenografts was markedly increased by hydralazine. In conclusion, hypoxia reduced accumulation of (99m)Tc-MIBI and (201)Tl in tumour cells. Accordingly, hypoxia may be an important factor in terms of the interpretation of scintigraphic findings obtained with these tracers for pre-therapeutic prediction of tumour response to treatment. Furthermore, the enhanced (99m)Tc-HL91 accumulation in hypoxic tumour cells indicates the usefulness of this tracer in this regard.

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“…7d) the accumulation rate of 99m Tc-tetrofosmin in tissue has been considered to be identical to the supply rate of this tracer into the capillary bed, and therefore should represent regional flow (26). However, 99m Tc-tetrofosmin uptake can be modified by the Na+/H+ antiporter and mitochondrial un-coupler, suggesting that the 99m Tc-tetrofosmin uptake can be influenced by the membrane potential and mitochondrial integrity (27)(28)(29)(30). It was also shown that myocardial Tl by means of the table-look-up approach.…”

Section: Figmentioning

confidence: 99%