Hunjan S, Zhao D, Constantinescu A, Hahn E W, Antich P P, Mason R P
Advanced Radiological Sciences, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9058, USA.
Int J Radiat Oncol Biol Phys. 2001 Mar 15;49(4):1097-108. doi: 10.1016/s0360-3016(00)01460-7.
We have developed an enhanced approach to measuring regional oxygen tension (pO(2)) dynamics in tumors. The technique is demonstrated in a group of 8 Dunning prostate rat tumors (R3327-AT1) with respect to respiratory challenge.
Hexafluorobenzene was injected directly into the tumors of anesthetized rats. (19)F nuclear magnetic resonance echo planar imaging relaxometry was performed to obtain maps of regional tumor oxygenation under baseline conditions and when the inhaled gas was changed to oxygen or carbogen.
Sequential pO(2) maps required 8 min, with a typical precision of 1-3 torr at 30-100 individual regions across a tumor. When rats breathed 33% oxygen, distinct heterogeneity was observed for baseline oxygenation in each tumor with pO(2) values ranging from hypoxic to greater than 100 torr. Larger tumors showed significantly lower baseline pO(2). Respiratory challenge with oxygen or carbogen produced significant increases in tumor oxygenation with a close correlation between the response to each gas at individual locations. Regions of both small and large tumors responded to respiratory challenge, but the rate was generally much faster in initially well-oxygenated regions.
Regional pO(2) was assessed quantitatively and the response of multiple individual tumor regions observed simultaneously with respect to interventions.
我们开发了一种增强的方法来测量肿瘤区域的氧张力（pO₂）动态变化。该技术在一组8只患有邓宁前列腺大鼠肿瘤（R3327 - AT1）的大鼠中针对呼吸刺激进行了演示。
将六氟苯直接注射到麻醉大鼠的肿瘤中。采用¹⁹F核磁共振回波平面成像弛豫测量法，在基线条件下以及当吸入气体改为氧气或卡波金时，获取肿瘤区域氧合图。
连续的pO₂图绘制需要8分钟，在肿瘤内30 - 100个单独区域，典型精度为1 - 3托。当大鼠呼吸33%的氧气时，观察到每个肿瘤的基线氧合存在明显的异质性，pO₂值范围从缺氧到大于100托。较大的肿瘤显示出明显较低的基线pO₂。用氧气或卡波金进行呼吸刺激会使肿瘤氧合显著增加，在各个位置对每种气体的反应之间存在密切相关性。大小肿瘤的区域对呼吸刺激均有反应，但在最初氧合良好的区域反应速度通常要快得多。
对区域pO₂进行了定量评估，并观察到多个单个肿瘤区域对干预措施的反应。
