Multi-modality detection of RCC Recurrence Post Ablation

肾细胞癌（RCC）占所有癌症的3-5%。局部消融是一种 推荐用于T1 a肾癌（约占所有RCC的25%）的治疗，尤其是对于 治疗因肾功能下降或孤立肾而不适合手术的患者。 消融术后检测复发的成像方案各不相同，但主要依赖于对比增强的计算机成像。 断层扫描（CECT）或对比增强磁共振成像（CEMRI），间隔3-12个月。 然而，基于消融腔内的对比度增强的检测的复发检测可以是可实现的。 对两种模式都有挑战性-由于大多数复发的影像学结果是非特异性的， 肿瘤大小的变化，脂肪坏死和瘢痕形成的增强，以及钙化的发展 治疗后。另外，由于模态和造影剂，这些技术可能存在问题 禁忌症。作为CECT和CEMRI的替代方法，超声造影（CEUS）已获得 接受各种临床应用。在小型试点研究中，我们的团队已经证明了 CEUS监测经皮消融后残余和复发的RCC，灵敏度为100%， 无不良事件。虽然令人鼓舞，但我们的研究结果是基于相对较小的样本量， 该技术的总体特异性范围为75- 96%，主要是由于无法正确识别 消融腔与周围肾皮质的边界。为了评估CEUS的临床前景，我们 建议进行一项更大规模、充分把握度的研究，在多个机构招募患者，并使用多模态 成像技术，以克服这些限制，并使临床采用。在第一个具体目标中，我们将 表征两者的灵敏度、特异性、阳性和阴性预测值以及阅片者间一致性 2D CEUS和对比增强横断面成像用于检测消融后复发的RCC;我们将 使用长期随访成像和组织病理学的组合作为参考标准，而不是依赖于 在CECT或CEMRI上。在每个研究中心，在CEUS方面具有不同经验水平的盲态放射科医生将解释 考试，使我们能够定义这些参数，同时也量化读者的变化。第二个目标，我们 将评价2D CEUS与患者的 治疗前横断面成像，我们假设这将提供更好的描绘初始肿瘤 边界在第三个目标中，我们将评估使用多模态容积CEUS的潜在附加值， 检测消融后RCC复发，以及先进的多普勒非造影技术作为探索性 子目标。最后，我们将探索使用从2D/3D CEUS检查中提取的定量参数来确定 如果这能提高CEUS的整体性能。在研究结束时，我们希望解决目前的问题， RCC复发监测成像与全功率CEUS研究的局限性，以支持临床采用， 同时还通过使用多模态和定量成像来解决先前的限制。

Project Summary: Renal cell carcinoma (RCC) accounts for 3-5% of all cancers. Localized ablation is a recommended treatment for T1a renal cancers (approximately 25% of all RCC) and particularly important for the treatment of patients who are poor surgical candidates due to diminished renal function or with a solitary kidney. Post-ablation imaging protocols for detection of recurrence vary, but mainly rely on contrast-enhanced computed tomography (CECT) or contrast-enhanced magnetic resonance imaging (CEMRI) at 3-12 months intervals. However, detection of relapse based on detection of contrast enhancement within the ablation cavity can be challenging on both modalities – due to most imaging findings of recurrence being nonspecific because of changes in tumor size, enhancement from fat necrosis and scarring, and the development of calcifications following therapy. Additionally, these techniques can be problematic due to modality and contrast agent contraindications. As an alternative to CECT and CEMRI, contrast-enhanced ultrasound (CEUS) has gained acceptance for a variety of clinical applications. In small pilot studies, our group has demonstrated the ability of CEUS to monitor for both residual and recurrent RCC following percutaneous ablation with 100% sensitivity and no adverse events. While encouraging, our findings were based on a relatively small sample size and, with an overall specificity of the technique that ranged from 75-96%, primarily due to an inability to properly identify the boundaries of the ablation cavity from the surrounding renal cortex. To assess the clinical promise of CEUS, we propose a larger, fully powered study, recruiting patients across multiple institutions and using multi-modality imaging techniques to overcome these limitations and enable clinical adoption. In our first specific aim, we will characterize the sensitivity, specificity, positive and negative predictive value, and inter-reader agreement of both 2D CEUS and contrast-enhanced cross-sectional imaging for detecting recurrent RCC following ablation; we will use a combination of long-term follow-up imaging and tissue pathology as a reference standard, instead of relying on CECT or CEMRI. At each site, blinded radiologists with varying experience levels in CEUS will interpret exams, enabling us to define these parameters while also quantifying reader variability. In the second aim, we will evaluate the potential improvement to the qualitative assessments of 2D CEUS when fused with the patient's pre-treatment cross-sectional imaging, which we hypothesize will provide better delineation of the initial tumor boundary. In the third aim, we will assess the potential added value of using multi-modality volumetric CEUS for detecting RCC recurrence post ablation and also an advanced Doppler non-contrast technique as an exploratory sub-aim. Finally, we will explore use of quantitative parameters extracted from 2D/3D CEUS exams to determine if this improves the overall performance of CEUS. At the study's conclusion, we hope to address the current limitations in RCC recurrence surveillance imaging with fully powered CEUS study to support clinical adoption, while also addressing prior limitations through the use of multi-modality and quantitative imaging.