Mason R P, Rodbumrung W, Antich P P
Advanced Radiological Sciences, U.T. Southwestern Medical Center, Dallas, TX 75235-9058, USA.
NMR Biomed. 1996 May;9(3):125-34. doi: 10.1002/(SICI)1099-1492(199605)9:3<125::AID-NBM405>3.0.CO;2-F.
We have surveyed the sensitivity of the spin lattice relaxation rates of the 19F resonances of several perfluorocarbons to changes in oxygen tension and temperature. Hexafluorobenzene was found to exhibit exceptional sensitivity to changes in oxygen tension, and we have exploited this phenomenon to measure tumor oxygen tension following intratumoral injection. When 20 microliters hexaflourobenzene were injected they remained localized and the biodistribution was readily assessed on the basis of combined 1H and 19F three-dimensional MRI. Relaxation measurements indicated a typical baseline oxygen tension of 4.0 +/- 1.5 torr in the central region of a Dunning prostate R3327-AT1 tumor when the rat breathed 66% oxygen. Altering the inspired oxygen concentration to 100% produced a modest increase in pO2 (5.6 +/- 0.7 torr; p < 0.1). Significantly, the precision of these measurements should facilitate NMR investigations of radiobiological hypoxia. Intra-tumoral injection allowed measurements from regions not normally accessible to infused perfluorocarbons and provides an additional approach to measuring tumor oxygenation.
我们已经研究了几种全氟碳化合物的19F共振的自旋晶格弛豫率对氧张力和温度变化的敏感性。发现六氟苯对氧张力变化表现出异常的敏感性，并且我们利用这一现象在瘤内注射后测量肿瘤氧张力。当注射20微升六氟苯时，它们会保持在局部位置，并且基于1H和19F联合三维磁共振成像（MRI）可以很容易地评估其生物分布。弛豫测量表明，当大鼠呼吸66%氧气时，邓宁前列腺R3327-AT1肿瘤中心区域的典型基线氧张力为4.0±1.5托。将吸入氧浓度改变为100%会使pO2适度增加（5.6±0.7托；p<0.1）。重要的是，这些测量的精度应有助于对放射生物学缺氧的核磁共振研究。瘤内注射允许从通常无法接触注入的全氟碳化合物的区域进行测量，并提供了一种测量肿瘤氧合的额外方法。
