Coates Allan L, Green Maria, Leung Kitty, Louca Emily, Tservistas Markus, Chan Jeffrey, Ribeiro Nancy, Charron Martin
The Lung Biology Program, Research Institute of the Hospital for Sick Children, University of Toronto, Toronto, Canada.
J Aerosol Med. 2007 Fall;20(3):320-30. doi: 10.1089/jam.2007.0620.
In quantifying aerosol delivery, the drug is often mixed with a radiolabel such as (99m)Tc-DTPA whose deposition is used as a proxy for the drug. (99m)Tc-DTPA deposited in the lung is cleared by a combination of absorption into the pulmonary circulation and mucociliary clearance. If administration is not instantaneous, the image will not include that clearance during administration, a problem raised if comparing devices with different administration times. However, if rates of clearance are measured, it will be possible to "correct" the initial image for the clearance that occurred during administration and before counting. Five adult males inhaled a 5-mL solution containing (99m)Tc-DTPA from a breath enhanced jet nebulizer (LC Plus)over the course of 10 min and a 1.25-mL solution from a vibrating membrane device (eFlow), which was delivered in 2.5 min. Quality assurance was the radioactivity count balance (RCB) defined as the difference in the total radioactivity pre-nebulization less post, divided by pre, and expressed as a percentage. Attenuation calculations used a (57)Co flood source (Macey and Marshall). The "correction" for the clearance of (99m)Tc-DTPA was 0.91 +/- 0.04 (mean +/- SD) for the LC Plus) and 0.96 +/- 0.02 for the eFlow). RCB was -0.6 +/- 3.5% for the LC Plus and -4.7 +/- 6.4% for the eFlow, implying acceptable accuracy. For the LC Plus, lung deposition was 15.9(13.4, 18.4)% (mean and 95% CI) of the charge dose, and for the eFlow it was 32.0(29.0, 35.0)%. This technique gave an acceptable level of accuracy for quantitative planar imaging and allowed the comparison of delivery from devices with very different rates of delivery.
在量化气雾剂递送时，药物通常与放射性标记物混合，如（99m）Tc-DTPA，其沉积用作药物的替代指标。沉积在肺部的（99m）Tc-DTPA通过吸收进入肺循环和黏液纤毛清除的组合来清除。如果给药不是瞬间完成的，图像将不包括给药期间的清除情况，这在比较具有不同给药时间的装置时会产生问题。然而，如果测量清除率，就有可能对给药期间和计数前发生的清除进行“校正”初始图像。五名成年男性在10分钟内从呼吸增强型喷射雾化器（LC Plus）吸入含有（99m）Tc-DTPA的5毫升溶液，并在2.5分钟内从振动膜装置（eFlow）吸入1.25毫升溶液。质量保证是放射性计数平衡（RCB），定义为雾化前总放射性与雾化后总放射性之差除以雾化前总放射性，并以百分比表示。衰减计算使用（57）Co泛源（梅西和马歇尔）。（99m）Tc-DTPA清除的“校正”对于LC Plus为0.91±0.04（平均值±标准差），对于eFlow为0.96±0.02。LC Plus的RCB为-0.6±3.5%，eFlow的RCB为-4.7±6.4%，这意味着准确性可以接受。对于LC Plus，肺部沉积为注入剂量的15.9（13.4，18.4）%（平均值和95%置信区间），对于eFlow为32.0（29.0，35.0）%。该技术为定量平面成像提供了可接受的准确度水平，并允许比较具有非常不同递送速率的装置的递送情况。
