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

放射治疗是一种有效而安全的癌症治疗方法。大约50%的癌症患者从这种治疗中受益，也就是说，每年有近10万加拿大癌症患者受益。近距离放射治疗是放射治疗的一种形式，将放射源放置在肿瘤内或肿瘤附近，使用短期植入的细中空管(导管)，向肿瘤提供高剂量的辐射，同时保持对周围健康组织的低剂量。然而，传统的近距离放射治疗的剂量分布在各个方向上都是相同的，导致剂量泄漏到对辐射敏感的健康组织。这项提议旨在开发一种新型的辐射传输系统，通过在植入的中空管中加入辐射屏蔽物来操纵辐射剂量以符合肿瘤的形状，即该传输系统将调制从近距离治疗源发射的辐射的强度。在治疗过程中，防护罩可以旋转，将辐射引向肿瘤，远离健康组织。开发和使强度调制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，同时降低毒性，将提高加拿大前列腺癌、乳腺癌、宫颈癌、子宫癌、阴道癌、外阴癌、头颈部癌和食道癌的治愈率和生活质量。此外，这项提议将为本科生和研究生提供在辐射肿瘤学、辐射物理学、生物学、计算机和工程学等多学科环境中工作的机会。

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.