Multiparametric MRI-guided Prostate HDR Brachytherapy with Focal Tumor Boost

项目摘要/摘要 在美国，每6名男性中就有1人患有前列腺癌。尽管技术进步，前列腺癌放射治疗仍然 结果：高危前列腺癌患者的局部控制和生存率较差-超过50%的患者 患有高危疾病的患者将在前列腺癌放射治疗后复发。组织病理学研究显示 前列腺内的主要癌灶与放疗后局部复发的部位有关。它 已被证明，最先进的多参数磁共振成像(MP-MRI)结合了解剖成像和 功能磁共振成像技术是明确显性前列腺内病变(DIL)的最佳方法。 高剂量率(HDR)近距离放射治疗，具有精确的辐射剂量传递、放射生物学优势和更低的 成本，已成为前列腺癌患者越来越受欢迎的治疗方式。中的几项研究 HDR近距离放射治疗显示，DIL的放射强化结合全前列腺治疗可以改善 局部肿瘤控制，不会造成过量毒性。然而，由于DIL的解剖位置和大小， 约60%的患者无法在不增加器官保护的情况下达到预期的DIL增强剂量覆盖范围 当前HDR Boost实践中的风险(OAR)容差。我们假设Dil靶向的HDR导管 放置将显著改善焦点增强HDR中DILS的可实现的增强剂量覆盖 近距离放射治疗。建议的研究是开发一种DIL靶向、美国引导的HDR前列腺近距离放射治疗 用焦点助推器。具体地说，我们提出了一种新颖的MRI-US-CT可变形配准，它可以 将MP-MRI定义的DIL纳入实时US以指导HDR导管放置以提高成功率 评价可实现的最佳剂量增加，并平扫CT以指导HDR治疗中局部Dil Boost的剂量传递。 这一整体项目建立在三个不可或缺的组成部分上：1)PI获奖的前列腺分割和 配准技术，2)MP-MRI提供的DIL信息，以及3)精确的放射传输 由HDR近距离放射治疗技术提供的系统。引入以DIL为目标的HDR的潜在好处 加强近距离放射治疗，可以照射整个前列腺，同时增加更高的剂量 对MP-MRI定义的DILS来说是巨大的。在这个项目中，我们将1)开发和优化前列腺分割 和配准算法，2)定量评估这些算法的一致性和准确性 幻影和患者数据，以及3)评估建议的DIL目标Boost HDR的性能 常规HDR近距离放射治疗，并检验其临床益处。这个项目的成功完成将 克服关键障碍，推进前列腺癌的个性化HDR近距离放射治疗，从而提供 在保留正常组织以改善局部控制的同时，集中增加对DILS的辐射剂量的方法， 前列腺癌患者，特别是晚期前列腺癌患者的长期生存和生活质量 癌症。

Project Summary/Abstract Prostate cancer affects 1 in 6 men in USA. Despite the technological advances, prostate radiotherapy still results in poor local control and survival for patients with high-risk prostate cancer – over 50% of the patients with high-risk disease will experience relapses following prostate radiotherapy. Histopathologic studies showed that dominant cancer foci within the prostate are associated with sites of local recurrence post radiotherapy. It has been proven that the state-of-the-art multiparametric MRI (mp-MRI) combining anatomic imaging with functional MRI techniques can provide the best performance to define dominant intraprostatic lesion (DIL). High-dose-rate (HDR) brachytherapy, with precise radiation-dose delivery, radiobiological advantage and lower cost, has become an increasing popular treatment modality for patients with prostate cancer. A few studies in HDR brachytherapy have shown that radiotherapy boost for a DIL with whole prostate treatment can improve local tumor control without causing excess toxicity. However, due to the anatomic location and size of a DIL, approximate 60% patients could not achieve the expected DIL boost dose coverage without increasing organ- at-risk (OAR) tolerances in current HDR boost practice. We hypothesize that DIL-targeted HDR catheter placement will significantly improve achievable boost dose coverage for DILs in focal boost HDR brachytherapy. The proposed research is to develop a DIL-targeted, US-guided HDR prostate brachytherapy with focal boost. Specifically, we propose to develop a novel MRI-US-CT deformable registration, which can incorporate mp-MRI-defined DIL into real-time US to guide HDR catheters placement to improve the probability of achievable optimal dose boost, and panning CT to guide focal DIL boost dose delivery in HDR treatment. This overall project is built on three integral components: 1) the PI’s award-winning prostate segmentation and registration technologies, 2) the DIL information provided by mp-MRI, and 3) a precise radiation delivery system offered by the HDR brachytherapy technique. The potential benefit of introducing DIL-targeted HDR boost brachytherapy that can irradiate the whole prostate while simultaneously and focally boost a higher dose to mp-MRI-defined DILs is enormous. In this project, we will 1) develop and optimize prostate segmentation and registration algorithms, 2) quantitatively evaluate the consistency and accuracy of these algorithms using phantom and patient data, and 3) evaluate the performance of the proposed DIL-targeted boost HDR with conventional HDR brachytherapy and examine its clinical benefit. Successful completion of this project will overcome a critical barrier to advance personalized HDR brachytherapy for prostate cancer, thus providing a way to focally boost the radiation dose to the DILs while sparing the normal tissue to improve local control, long-term survival and quality of life for prostate-cancer patients, particularly those with advanced prostate cancer.