HDR Brachytherapy System Using Ytterbium-169

描述（由申请人提供）：本项目的目的是开发一种改进的高剂量率近距离放射治疗系统，用于基于低能伽马射线源169镱的癌症治疗。这种发展将实现上级剂量优化的益处，其附带改善治疗反应，沿着具有后装高剂量率临时近距离放射治疗源可获得的潜在更好的治疗效果。该计划将证明，这种放射性核素屏蔽要求的降低可以转化为治疗靶点的更适形剂量分布，减少患者的附带剂量，并消除目前使用的192铱源所需的专用屏蔽治疗室的高资本成本。我们的目的是证明临床和经济效益的建议方法超过目前实行的高剂量率近距离放射治疗使用192铱。 除了169镱的低能量/高活性源之外，我们还打算开发屏蔽治疗设备，以改善剂量符合性和侧支局部屏蔽，从而允许在最低屏蔽治疗室中进行HDR近距离放射治疗。这个系统将消除大量资本投资的障碍。我们预计，这一发展将扩大高剂量率近距离放射治疗的使用到更多的临床中心，部分原因是由于这种新的来源，术中治疗将在常规（即无屏蔽）手术室物理上是可能的。随着HDR近距离放射治疗在前列腺癌治疗中的使用越来越多，以及最近对使用该技术治疗乳腺癌的热情，这一发展在此时尤为重要。

DESCRIPTION (provided by applicant): The objective of this program is to develop an improved high dose rate brachytherapy system for the treatment of cancer based on the low-energy gamma ray source 169Ytterbium. Such development would achieve the benefits of superior dose optimization with its collateral improvement in therapeutic response, along with potentially better treatment efficacy available with afterloaded high dose rate temporary brachytherapy sources. The program will demonstrate that the reduced shielding requirements for this radionuclide can be translated into more conformal dose distributions to the treatment target, reduction of collateral dose to the patient and elimination of the high capital cost of a dedicated, shielded treatment room such as is required for the currently-used 192Iridium source. We aim to demonstrate both clinical and economic benefits for the proposed method over currently practiced high dose rate brachytherapy treatment using 192Iridium. In addition to a low-energy/high activity source of 169Ytterbium, we intend to develop shielded treatment devices to improve dose conformity and collateral local shielding to permit the performance of HDR brachytherapy in minimally shielded treatment room. This system will remove the barrier of a large capital investment. We anticipate that this development will extend the use of high dose rate brachytherapy to a much larger number of clinical centers, partly because with this new source, intraoperative treatments would be physically possible in regular (i.e. unshielded) operating rooms. With the increased use of HDR brachytherapy for the treatment of prostate cancer, and with the recent enthusiasm about the treatment of breast cancer using this technique, this development is particularly important at this time.