Novel Delivery System for High Dose Rate Intensity Modulated Brachytherapy with Yb-169 as a Radiation Source

放射治疗是一种安全有效的癌症治疗方法。大约50%的癌症患者受益于这种治疗，也就是说，每年有近10万名加拿大癌症患者。近距离放射治疗是一种放射疗法，使用短时间植入的薄空心管（导管）将放射源放置在肿瘤内部或附近，对肿瘤给予高剂量的辐射，同时对周围的健康组织保持低剂量。然而，传统近距离放射治疗的剂量分布在各个方向上是相同的，导致剂量溢出到辐射敏感的健康组织。该提案旨在开发一种新型的辐射输送系统，通过在植入的空心管中加入辐射屏蔽来控制辐射剂量，使其符合肿瘤的形状，即输送系统将调节近距离治疗源发射的辐射强度。在治疗过程中，护盾可以旋转，将辐射引向肿瘤，远离健康组织。发展并使调强近距离放射治疗临床可用，将显著提高近距离放射治疗的潜力，降低毒性，提高加拿大人前列腺癌、乳腺癌、宫颈癌、子宫癌、阴道癌、外阴癌、头颈癌和食管癌的治愈率和生活质量。此外，该计划将提供本科生和研究生在放射肿瘤学，放射物理学，生物学，计算机和工程的多学科环境中工作。

Radiotherapy is an effective and safe treatment for cancer. Approximately 50% of cancerpatients benefit from this treatment, that is, close to 100,000 Canadians with cancer eachyear. Brachytherapy, is a form of radiotherapy where radioactive sources are placed inside ornear the tumours using thin, hollow tubes (catheters) implanted for a short period of time,giving a high radiation dose to the tumour while maintaining a low dose to surrounding healthy tissues. However, dose distribution in conventional brachytherapy is identical in all directions resulting in dose spillage to radiation sensitivehealthy tissues. This proposal aims to develop a novel radiation delivery system that willmanipulate the radiation dose to conform to the shape of a tumour by incorporating radiationshields inside the implanted hollow tubes, i.e. the delivery system will modulate the intensityof the emitted radiation from the brachytherapy source. The shields can rotate during thetreatment, direct the radiation towards the tumour and away from healthy tissues. Developing and making intensitymodulated brachytherapy clinically available, will significantly improve the potential ofbrachytherapy with reduced toxicity will increase the cure rates and improve the quality of lifefor Canadians with prostate, breast, cervical, uterine, vaginal, vulvar, head & neck andoesophageal cancers. In addition, this proposal will offer undergraduate and graduate studentto work in a multidisciplinary environment with radiation oncology, radiation physics, biology,computing and engineering.