Stüben G, Stuschke M, Knühmann K, Horsman M R, Sack H
Department of Radiotherapy, Strahlenklinik im Universitätsklinikum Essen, Germany.
Radiother Oncol. 1998 Aug;48(2):143-8. doi: 10.1016/s0167-8140(98)00006-1.
This was an investigation to study the effect of giving carbogen and nicotinamide (CON) on pO2 and the radiation response of human xenografted tumours.
The human xenografts were two sarcomas (ENE2 and ES3) and a glioblastoma (HTZ17). Nicotinamide (500 mg/ kg, i.p.) was administered 60 min before PO2 measurements and irradiation, while carbogen was given for 5 min before and during these treatments. Tumour pO2 was measured with an Eppendorf electrode and radiation response was assessed by local tumour control following irradiation with 10 daily fractions.
All three xenografts were found to be poorly oxygenated (about 80% of all pO2 values were < or =2.5 mmHg). CON treatment improved the oxygenation status in all three tumours such that 65, 52 and 71% of the pO2 values were < or =2.5 mmHg in ENE2, ES3 and HTZ17, respectively. However, only in ES3 was this decrease significant. The TCD50 doses for all tumours were around 52-54 Gy. No significant improvement was seen with CON in ENE2 (TCD50 = 48 Gy) and HTZ17 (TCD50 = 56 Gy), but for the ES3 xenograft a significant decrease to 42 Gy was found.
The three tumours used in this study appeared to show the same level of hypoxia as measured both by pO2 and radiation response. However, only one tumour showed a significant improvement after CON treatment, suggesting that not all hypoxic human tumours might benefit from this type of therapy.
本研究旨在探讨给予卡波金和烟酰胺（CON）对人异种移植肿瘤的氧分压（pO2）及放射反应的影响。
人异种移植肿瘤包括两种肉瘤（ENE2和ES3）和一种胶质母细胞瘤（HTZ17）。在进行pO2测量及照射前60分钟腹腔注射烟酰胺（500毫克/千克），同时在这些治疗前及治疗期间给予卡波金5分钟。用Eppendorf电极测量肿瘤pO2，并通过每日10次分割照射后的局部肿瘤控制来评估放射反应。
发现所有三种异种移植肿瘤均存在氧合不足（所有pO2值中约80%≤2.5毫米汞柱）。CON治疗改善了所有三种肿瘤的氧合状态，使得ENE2、ES3和HTZ17中分别有65%、52%和71%的pO2值≤2.5毫米汞柱。然而，只有在ES3中这种降低才具有显著性。所有肿瘤的肿瘤控制剂量50（TCD50）约为52 - 54戈瑞。在ENE2（TCD50 = 48戈瑞）和HTZ17（TCD50 = 56戈瑞）中，CON治疗未显示出显著改善，但对于ES3异种移植肿瘤，TCD50显著降至42戈瑞。
本研究中使用的三种肿瘤通过pO2和放射反应测量显示出相同程度的缺氧。然而，只有一种肿瘤在CON治疗后显示出显著改善，这表明并非所有缺氧的人肿瘤都可能从这种治疗中获益。
