Gabalski E C, Adam M, Pinto H, Brown J M, Bloch D A, Terris D J
Division of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, California 94305-5328, USA.
Laryngoscope. 1998 Dec;108(12):1856-60. doi: 10.1097/00005537-199812000-00017.
Considerable evidence exists to suggest that tumor hypoxia results in radioresistance. Historically, it has been difficult to assess tumor oxygen tension levels reliably. These levels can now be assessed in head and neck malignancies using the Eppendorf pO2 histograph, which uses a fine-needle electrode and a computerized micromanipulator. This technology was used to compare the pretreatment tumor oxygen tension level in lymph node metastases of patients with head and neck cancer to measurements taken during nonsurgical treatment after a partial response had been achieved.
Prospective study.
Oxygen tension levels were measured in the cervical lymph nodes of 10 patients with biopsy-proven head and neck squamous cell carcinoma and cervical metastases who were being treated with nonsurgical management. These levels were obtained using the Eppendorf pO2 histograph system. Measurements were taken before the start of treatment and were repeated when the size of the cervical metastatic node had decreased by 50%. Normal subcutaneous tissue was measured during the same session. The mean and median pO2 levels, as well as the percentage of measurements with pO2 less than 5 mm Hg were determined.
A mean of 72.6 measurements per session was taken from each lymph node. The median tumor pO2 measurement fell from a mean (+/-SD) of 13.9+/-8.0 mm Hg to 7.3+/-9.9 mm Hg. Even more dramatic, however, was the substantial increase in the percentage of values less than 5 mm Hg, a rise from 29% to 52%.
While there is variability both in the pretreatment oxygenation of head and neck cervical metastases and in the change in tumor oxygen tension during treatment, there appears to be a decrease in the overall oxygenation of the tumors. The dramatic increase in very low oxygen measurements may reflect selective survival of radioresistant or chemoresistant hypoxic tumor cells. Cells at the very low level would be expected to be radiobiologically hypoxic (resistant to radiation-induced cell kill).
有大量证据表明肿瘤缺氧会导致放射抗性。从历史上看，可靠地评估肿瘤氧张力水平一直很困难。现在可以使用Eppendorf pO2组织血氧仪来评估头颈部恶性肿瘤中的这些水平，该仪器使用细针电极和计算机化微操纵器。这项技术被用于比较头颈癌患者淋巴结转移灶的治疗前肿瘤氧张力水平与部分缓解后非手术治疗期间的测量值。
前瞻性研究。
对10例经活检证实为头颈部鳞状细胞癌并伴有颈部转移且正在接受非手术治疗的患者的颈部淋巴结进行氧张力水平测量。这些水平是使用Eppendorf pO2组织血氧仪系统获得的。在治疗开始前进行测量，当颈部转移淋巴结大小缩小50%时重复测量。在同一时间段内测量正常皮下组织。确定pO2水平的平均值、中位数以及pO2小于5 mmHg的测量值百分比。
每个淋巴结每次测量平均进行72.6次。肿瘤pO2测量值的中位数从平均（±标准差）13.9±8.0 mmHg降至7.3±9.9 mmHg。然而，更显著的是，小于5 mmHg的值的百分比大幅增加，从29%升至52%。
虽然头颈部颈部转移灶的治疗前氧合情况以及治疗期间肿瘤氧张力的变化都存在变异性，但肿瘤的总体氧合似乎有所下降。极低氧测量值的显著增加可能反映了放射抗性或化学抗性缺氧肿瘤细胞的选择性存活。极低水平的细胞预计在放射生物学上是缺氧的（对辐射诱导的细胞杀伤有抗性）。
