HDR Brachytherapy System Using Ytterbium-169

描述(申请人提供)：该计划的目标是开发一种改进的基于低能伽马射线源169YtTb的癌症高剂量率近距离放射治疗系统。这样的发展将实现更好的剂量优化的好处，并伴随着治疗反应的改善，以及后装高剂量率临时近距离放射治疗来源可能获得的更好的治疗效果。该计划将证明，这种放射性核素屏蔽需求的减少可以转化为治疗目标的更适形剂量分布，减少患者的附带剂量，并消除目前使用的192Ir源所需的专用屏蔽治疗室的高昂资本成本。我们的目标是证明与目前使用192Ir的高剂量率近距离放射治疗相比，建议的方法在临床和经济上都有好处。 除了169YtTb的低能量/高活度源外，我们还打算开发屏蔽治疗设备，以改善剂量一致性和附带的局部屏蔽，以便在最小屏蔽的治疗室中进行HDR近距离放射治疗。这一系统将消除巨额资本投资的障碍。我们预计，这一发展将把高剂量率近距离放射治疗的使用扩展到更多的临床中心，部分原因是有了这种新的来源，术中治疗将在常规(即无屏蔽)手术室中进行物理上的可能性。随着HDR近距离放射治疗前列腺癌的使用越来越多，以及最近人们对使用这种技术治疗乳腺癌的热情，这一发展在这个时候尤为重要。

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.