Nguyen France, Rubino Carole, Guerin Sylvie, Diallo Ibrahima, Samand Akthar, Hawkins Mike, Oberlin Odile, Lefkopoulos Dimitri, De Vathaire Florent
INSERM U 605, Villejuif, France; Institut Gustave Roussy, Villejuif cedex, France.
Int J Radiat Oncol Biol Phys. 2008 Mar 1;70(3):908-15. doi: 10.1016/j.ijrobp.2007.10.034.
After successful treatment of cancers in childhood, the occurrence of second malignant neoplasm (SMN) came to the fore. Few studies have considered the relationship between the radiation dose received and the risk of developing an SMN. To take into account the heterogeneity of the dose distribution so as to evaluate the overall risk of an SMN after a childhood cancer, we therefore focused on the integral dose restricted to the irradiated fields.
The study was performed in a cohort of 4,401 patients who were 3-year survivors of all types of childhood cancer treated between 1947 and 1986 in France and Great Britain. For each patient, the integral dose was estimated for the volume inside the beam edges.
We found a significant dose-response relationship between the overall risk of an SMN and the estimated integral dose. The excess relative risk for each incremental unit of the integral dose was only 0.008 in a linear model and 0.017 when a negative exponential term was considered, when adjusted for chemotherapy. The risk of SMN occurrence was 2.6 times higher in the case of irradiation. However among patients who had received radiotherapy, only those who had received the highest integral dose actually had a higher risk.
The integral dose in our study cannot be considered as a good predictor of later risks. However other studies with the same study design are obviously needed to evaluate the use of the integral dose as a tool for decision making concerning different radiotherapy techniques.
在儿童癌症成功治疗后，第二原发性恶性肿瘤（SMN）的发生成为关注焦点。很少有研究考虑过所接受的辐射剂量与发生SMN风险之间的关系。为了考虑剂量分布的异质性，以便评估儿童癌症后发生SMN的总体风险，我们因此聚焦于受照射野内的积分剂量。
该研究在一组4401名患者中进行，这些患者是1947年至1986年在法国和英国接受治疗的所有类型儿童癌症的3年幸存者。对于每位患者，估计束边缘内体积的积分剂量。
我们发现SMN的总体风险与估计的积分剂量之间存在显著的剂量反应关系。在调整化疗后，积分剂量每增加一个单位，线性模型中的超额相对风险仅为0.008，考虑负指数项时为0.017。接受放疗的患者发生SMN的风险高2.6倍。然而，在接受放疗的患者中，只有那些接受最高积分剂量的患者实际风险更高。
我们研究中的积分剂量不能被视为后期风险的良好预测指标。然而，显然需要其他具有相同研究设计的研究来评估积分剂量作为关于不同放疗技术决策工具的用途。
