Prediction of clinical radiosensitivity caused by ionising radiation during radiotherapy.

大约1%到5%的癌症患者在放射治疗期间暴露于电离辐射的正常组织中会出现明显的副作用。虽然放射治疗是一种有效的癌症治疗方法，但通常限制放射量以尽量减少这些严重副作用（放射敏感性）的发生率。这意味着没有放射敏感性的人没有得到最有益的辐射剂量。辐射生物学研究的一个主要目标是开发有效的预测措施，在治疗前识别出辐射敏感的个体。这种预测能力将使放射治疗剂量的个体化成为可能，这将导致肿瘤控制率的提高和与放射治疗相关的副作用发生率的减少。我们的目标是利用强大的微阵列技术在分子水平上了解辐射敏感性。利用微阵列技术，可以同时检测数千个基因的表达活性。我们有一个独特的组织库，建立了许多放射敏感和非敏感对照放疗患者。对来自这个独特组织库的样本使用微阵列技术可以使显示放射敏感性的个体的基因表达模式与其他人群区分开来。同时，还将使用另外两项测试来确定哪些人容易受到辐射敏感反应的影响，其中包括评估DNA修复途径和评估端粒（染色体末端的帽）的长度，这两项都已被证明与辐射敏感性有关。这项实验有望导致一种用于癌症患者接受放射治疗前的临床预测分析的发展。

Around one to five percent of cancer patients suffer from significant side effects in normal tissue exposed to ionizing radiation during radiotherapy. Although radiotherapy is an effective therapy for cancer treatment, the amount of radiation is generally restricted to minimize the incidence of these severe side effects (radiosensitivity). This means that individuals who don't have radiosensitivity are not getting the dose of radiation that would be most beneficial. A major goal of radiation biology research is to develop efficient predictive measures that could identify radiosensitive individuals prior to treatment. This predictive ability would enable the individualisation of radiotherapy radiation doses, which should result in improvement of tumour control rates and a reduction in the incidence of side effects associated with radiotherapy. We aim to understand radiosensitivity at the molecular level using the powerful technology of microarrays. Using microarray technology, thousands of genes can be tested for expression activity simultaneously. We have a unique tissue bank established from many radiosensitive and non-sensitive control radiotherapy patients. The use of microarray technology on samples from this unique tissue bank may enable the gene expression pattern of individuals that display radiosensitivity to be distinguished from the rest of the population. In conjunction, two additional tests will be used to determine who is susceptible to radiosensitive reactions which include assessment of a DNA repair pathway and assessment of the length of the telomeres (Caps on the ends of the chromosomes), both of which have been shown to be involved with radiosensitivy. This experimentation will hopefully lead to the development of a predictive assay for use in the clinic for cancer patients prior to receiving radiotherapy.