| 摘要 |
Administration of a radioisotopic compound by infusion over a period of time greater than two hours, preferably greater than twelve hours, greatly increases the maximum radioactivity that accumulates in the target cell. The efficacy of the administration of the radiolabeled compound can be increased about five times higher than prior bolus injection or short infusion methods. This method enhances the tumour to background ratio by increasing the actual radioligand accumulated inside the tumour cells. This technique works for any radiolabeled compound whose cellular uptake is limited by a cellular process of either binding to a cellular receptor or to a transport protein. Once the radiolabeled compound is bound and internalised, the ability of an unlabeled compound to compete with the radioligand is markedly decreased. The primary factor governing residence time after internalisation is the physical half-life of the radioisotope, not the biological half-life. The radioisotope used can be selected from the group consisting of 67Ga, 111In, 99mTc, 90Y, 86Y, 169Yb, 188Re, 125I, 124i, 123I, 129I, 131I and 77Br. FIG. 1 illustrates the uptake of 111In-pentetreotide as a function of time in a single patient for differing methods of administration.
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