Hunjan S, Mason R P, Constantinescu A, Peschke P, Hahn E W, Antich P P
Department of Radiology, UT Southwestern Medical Center, Dallas, TX 75235-9058, USA.
Int J Radiat Oncol Biol Phys. 1998 Apr 1;41(1):161-71. doi: 10.1016/s0360-3016(98)00020-0.
An accurate method for monitoring oxygen tension (pO2) of individual tumors could be valuable for optimizing treatment plans. We have recently shown that 19F nuclear magnetic resonance (NMR) spin-lattice relaxometry of hexafluorobenzene (HFB) provides a highly sensitive indicator of tumor oxygenation. We have now refined the methodology to provide enhanced precision, and applied the method to investigate dynamic changes in tumor oxygenation.
Dunning prostate adenocarcinoma R3327-AT1 was grown in the form of pedicles on the foreback of male Copenhagen rats. When the tumors reached approximately equal to 1 cm diameter, HFB (20 microl) was administered, either centrally or peripherally, by direct intratumoral (i.T) injection. Local pO2 was determined using pulse-burst saturation recovery (PBSR) 19F NMR spectroscopy on the basis of the spin-lattice relaxation rate, R1.
Interrogation of the central region of tumors provided typical values in the range pO2 = 1.4-6.4 mmHg, with a typical stability of +/-2 mmHg over a period of 20 min, when rats breathed 33% O2. Altering the inhaled gas to oxygen or carbogen (95% O2/5% CO2) produced no significant change. In contrast, interrogation of tumor periphery indicated baseline pO2 in the range 7.9-78.9 mmHg. Altering inspired gas produced significant changes (p < 0.0001) with O2 or carbogen, although the change was generally greater with carbogen. In each case, pO2 returned to baseline within 16 min of returning the inhaled gas to baseline.
We believe this method provides a valuable new approach with the requisite precision and accuracy to investigate tumor pO2.
一种准确监测个体肿瘤氧分压（pO2）的方法对于优化治疗方案可能具有重要价值。我们最近表明，六氟苯（HFB）的19F核磁共振（NMR）自旋晶格弛豫测量法可提供肿瘤氧合的高灵敏度指标。我们现在对该方法进行了改进以提高精度，并应用该方法研究肿瘤氧合的动态变化。
将邓宁前列腺腺癌R3327-AT1以蒂状形式种植在雄性哥本哈根大鼠的背部。当肿瘤直径达到约1 cm时，通过直接瘤内（i.T）注射将HFB（20微升）中央或周边给药。基于自旋晶格弛豫率R1，使用脉冲猝发饱和恢复（PBSR）19F NMR光谱法测定局部pO2。
当大鼠呼吸33% O2时，对肿瘤中央区域进行检测得到的典型值范围为pO2 = 1.4 - 6.4 mmHg，在20分钟内典型稳定性为±2 mmHg。将吸入气体改为氧气或卡波金（95% O2/5% CO2）未产生显著变化。相比之下，对肿瘤周边进行检测表明基线pO2范围为7.9 - 78.9 mmHg。改变吸入气体时，使用氧气或卡波金会产生显著变化（p < 0.0001），尽管使用卡波金时变化通常更大。在每种情况下，将吸入气体恢复到基线后，pO2在16分钟内恢复到基线。
我们认为该方法提供了一种有价值的新方法，具有研究肿瘤pO2所需的精度和准确性。
