Hagan P L, Taylor A, Chauncey D M, Schelbert H
Nuklearmedizin. 1977 Apr;16(2):76-8.
Previous studies have shown that radiolabeled tetracyclines tend to accumulate in infarcts and necrotic tumors. These results suggested that radiolabeled tetracyclines might also accumulate in necrotic abscesses or areas of inflammation. In order to develop a better abscess scanning agent, we compared the efficiency of 131I-tetracycline with 67Ga-citrate in labeling experimentally induced staphylococcal aureus abscesses in rats 24 and 72 hours after injection. In addition to evaluating 131I-tetracycline as an abscess scanning agent, we hoped to obtain data which might clarify the controversy regarding early versus late gallium scanning in suspected infection. 131I-tetracycline was chosen over 99mTc-tetracycline because the longer half-life of 131I would allow 72 hour imaging. Absolute concentrations of gallium in the abscess contents and in the surrounding areas of inflammation were significantly greater than the concentration of 131I-tetracycline at both 24 and 72 hours. With the exception of blood, muscle, and bone, the abscess-to-tissue activity ratios for gallium and 131I-tetracycline were similar; however, the ratio of gallium activity in the inflammed tissue to other tissues was greater than that of 131I-tetracycline for every tissue examined at both time periods. The data suggest that 131I-tetracycline has little potential as a general abscess scanning agent. The gallium tissue concentrations and tissue ratios suggest that abscesses which can be imaged at 72 hours can probably be imaged at 24 hours, thus allowing earlier initiation of appropriate therapy. Because of the higher lesion-to-blood ratio at 72 hours, a 72-hour scan would appear to be indicated before a scan is interpreted as normal.
先前的研究表明，放射性标记的四环素往往会在梗死灶和坏死肿瘤中蓄积。这些结果提示，放射性标记的四环素可能也会在坏死性脓肿或炎症区域蓄积。为了开发一种更好的脓肿扫描剂，我们比较了131I-四环素与枸橼酸镓在标记大鼠实验性诱导的金黄色葡萄球菌脓肿方面的效率，分别于注射后24小时和72小时进行观察。除了评估131I-四环素作为脓肿扫描剂外，我们还希望获得一些数据，以澄清在疑似感染中早期与晚期镓扫描的争议。选择131I-四环素而非99mTc-四环素，是因为131I较长的半衰期可实现72小时成像。在24小时和72小时时，脓肿内容物及周围炎症区域中镓的绝对浓度均显著高于131I-四环素的浓度。除血液、肌肉和骨骼外，镓和131I-四环素的脓肿与组织活性比相似；然而，在两个时间段对每个检测组织而言，炎症组织中镓活性与其他组织的比值均高于131I-四环素。数据表明，131I-四环素作为一种通用的脓肿扫描剂潜力不大。镓的组织浓度和组织比值表明，72小时时能够成像的脓肿在24小时时可能也能成像，从而能够更早地开始适当治疗。由于72小时时病变与血液的比值更高，在扫描结果判定为正常之前似乎应进行72小时扫描。
