Cooper R A, Carrington B M, Loncaster J A, Todd S M, Davidson S E, Logue J P, Luthra A D, Jones A P, Stratford I, Hunter R D, West C M
CRC Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, M20 4BX, Manchester, UK.
Radiother Oncol. 2000 Oct;57(1):53-9. doi: 10.1016/s0167-8140(00)00259-0.
The Eppendorf pO(2) histograph is the 'gold standard' method for measuring tumour oxygenation. The method is not suitable for widespread application because its use is limited to accessible tumours. A non-invasive imaging technique would be an attractive alternative. Therefore, the relationships between tumour oxygenation and dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters were investigated.
The study comprised 30 patients with carcinoma of the cervix. Tumour oxygenation was measured pre-treatment as median pO(2) and the proportion of values less than 5 mmHg (HP5) using a pO(2) histograph. Repeat measurements were obtained for nine patients following 40-45 Gy external beam radiotherapy giving a total of 39 measurements. Dynamic contrast-enhanced MRI using gadolinium was performed prior to obtaining the oxygenation data. Time/signal intensity curves were generated to obtain two standard parameters: maximum enhancement over baseline (SI-I) and the rate of enhancement (SI-I/s).
Using the 39 measurements, there was a significant correlation between SI-I and both median pO(2) (r=0.59; P<0.001) and HP5 (r=-0. 49; P=0.002). There was a weak, borderline significant correlation between SI-I/s and both median pO(2) (r=0.29; P=0.071) and HP5 (r=-0. 34; P=0.037). There was a significant relationship between tumour size and SI-I (r=0.54; P<0.001), but not SI-I/s. In 29 tumours, where data were available, there was no relationship between histological assessment of tumour angiogenesis (intra-tumour microvessel density; IMD) and either MRI parameter.
Tumour oxygenation levels measured using a pO(2) histograph correlate with dynamic contrast-enhanced MRI parameters. Therefore, non-invasive dynamic MRI may be a method for measuring hypoxia in human tumours.
Eppendorf氧分压组织图像仪是测量肿瘤氧合的“金标准”方法。但该方法不适用于广泛应用，因为其仅适用于可触及的肿瘤。一种非侵入性成像技术将是一种有吸引力的替代方法。因此，研究了肿瘤氧合与动态对比增强磁共振成像（MRI）参数之间的关系。
该研究纳入了30例宫颈癌患者。使用氧分压组织图像仪在治疗前测量肿瘤氧合，以氧分压中位数（pO₂）和低于5 mmHg的值所占比例（HP5）表示。9例患者在接受40 - 45 Gy外照射放疗后进行了重复测量，共获得39次测量数据。在获取氧合数据之前，使用钆剂进行了动态对比增强MRI检查。生成时间/信号强度曲线以获得两个标准参数：相对于基线的最大增强（SI-I）和增强速率（SI-I/s）。
利用这39次测量数据，SI-I与pO₂中位数（r = 0.59；P < 0.001）和HP5（r = -0.49；P = 0.002）均存在显著相关性。SI-I/s与pO₂中位数（r = 0.29；P = 0.071）和HP5（r = -0.34；P = 0.037）之间存在较弱的、临界显著的相关性。肿瘤大小与SI-I存在显著关系（r = 0.54；P < 0.001），但与SI-I/s无关。在29个可获取数据的肿瘤中，肿瘤血管生成的组织学评估（瘤内微血管密度；IMD）与任何一个MRI参数均无关系。
使用氧分压组织图像仪测量的肿瘤氧合水平与动态对比增强MRI参数相关。因此，非侵入性动态MRI可能是一种测量人体肿瘤缺氧情况的方法。
