Kotzerke J, Fenchel S, Guhlmann A, Stabin M, Rentschler M, Knapp F F, Reske S N
Nuklearmedizin (Radiologie III), Universität Ulm, Germany.
Nucl Med Commun. 1998 Aug;19(8):795-801. doi: 10.1097/00006231-199808000-00011.
Radioactive wires and other linear sources are currently being used in clinical trials as endovascular brachytherapy to prevent restenosis after percutaneous transluminal coronary angioplasty. A new concept is the use of a liquid-filled balloon containing a beta-emitting radioisotope. A major advantage is optimal delivery of the radioactivity to the vessel wall. Rhenium-188 (188Re) is a high-energy beta-emitter that is routinely available from a 188W/188Re generator in liquid form. Since 188Re-perrhenate could be released in the unlikely event of balloon rupture, we investigated whether, in analogy to pertechnetate, subsequent use of perchlorate can reduce the uptake of perrhenate in the thyroid. We performed static (n = 9) and dynamic (n = 11) thyroid scintigraphy with 99Tcm-pertechnetate to estimate the overall reduction in activity within 30 min and the washout from the thyroid after oral administration of 600 mg perchlorate (T1/2). In two patients, 188Re was injected to estimate the whole-body distribution and the discharge of thyroid activity after perchlorate use. Based on MIRD Dose Estimate Report No. 8 (valid for 99Tcm-pertechnetate), the radiation burden was calculated for intravenous administration of 188Re and competitive blocking with perchlorate. In 20 patients, 99Tcm uptake by the thyroid was reduced by 85% within 30 min by perchlorate. The mean (+/- S.D.) washout rate (T1/2) was 8 +/- 2 min in 11 patients. Perrhenate showed a whole-body distribution similar to that of pertechnetate and the thyroid activity could be displaced (T1/2 = 6.3 and 9.3 min, respectively) by oral administration of perchlorate, with reductions in uptake of 83% and 75% within 30 min, respectively. Whole-body scanning demonstrated no regional accumulation of 188Re-perrhenate with excretion by urine. Dose estimates gave an effective dose equivalent of 0.42 mSv MBq-1, which decreased to 0.16 mSv MBq-1 after perchlorate blocking. 188Re has favourable properties for endovascular brachytherapy via a balloon catheter and, in the unlikely event of balloon rupture, whole-body radiation can be reduced to 38% by subsequent oral administration of perchlorate.
放射性金属丝和其他线性源目前正在临床试验中用作血管内近距离放射疗法，以预防经皮腔内冠状动脉成形术后的再狭窄。一个新的概念是使用装有发射β射线的放射性同位素的充液球囊。一个主要优点是能将放射性物质最佳地输送到血管壁。铼-188（188Re）是一种高能β射线发射体，通常可从188W/188Re发生器以液体形式获得。由于在球囊破裂这种不太可能发生的情况下188Re-高铼酸盐可能会释放出来，我们研究了与高锝酸盐类似，随后使用高氯酸盐是否能减少甲状腺对高铼酸盐的摄取。我们用99Tcm-高锝酸盐进行了静态（n = 9）和动态（n = 11）甲状腺闪烁显像，以估计口服600mg高氯酸盐（T1/2）后30分钟内甲状腺内放射性活度的总体降低情况以及从甲状腺的清除情况。在两名患者中，注射了188Re以估计高氯酸盐使用后188Re的全身分布和甲状腺放射性活度的排出情况。根据MIRD剂量估计报告第8号（适用于99Tcm-高锝酸盐），计算了静脉注射188Re并用高氯酸盐进行竞争性阻断时的辐射剂量负担。在20名患者中，高氯酸盐在30分钟内使甲状腺对99Tcm的摄取减少了85%。11名患者的平均（±标准差）清除率（T1/2）为8±2分钟。高铼酸盐的全身分布与高锝酸盐相似，口服高氯酸盐可使甲状腺放射性活度移位（T1/2分别为6.3分钟和9.3分钟），30分钟内摄取量分别减少83%和75%。全身扫描显示没有188Re-高铼酸盐的局部蓄积，其通过尿液排泄。剂量估计得出有效剂量当量为0.42mSv MBq-1，高氯酸盐阻断后降至0.16mSv MBq-1。188Re对于通过球囊导管进行血管内近距离放射疗法具有良好的特性，并且在球囊破裂这种不太可能发生的情况下，随后口服高氯酸盐可将全身辐射降低至38%。
