Model-Based Treatment Planning for Focused Ultrasound Surgery

癌症是英国最常见的疾病之一。每年，它占所有死亡人数的近三分之一。对于晚期癌症患者，癌细胞通常会扩散到身体的其他部位。这个过程被称为转移，形成的继发性肿瘤被称为转移。骨转移是最常见的转移部位之一。晚期乳腺癌和前列腺癌患者中约2/3会发生骨转移，晚期肺癌、甲状腺癌和肾癌患者中约有1/3会发生骨转移。这会导致虚弱的疼痛，这对患者的生活质量有重大影响。最常见的减轻骨转移疼痛的治疗方法是外照射疗法。这是为了缓解症状和控制癌症的生长，以提高生活质量，而不是试图治愈患者(这被称为姑息治疗)。然而，多达三分之一的接受放射治疗的患者没有得到足够的疼痛缓解，而且由于辐射对体内健康组织的毒性，治疗不能重复。聚焦超声手术是一种非常有前途的缓解疼痛的替代疗法，也被称为高强度聚焦超声或HIFU。这项技术的工作原理是将一束紧密聚焦的超声波发射到组织中。在病灶处，超声波能量足以加热组织并在非常局部的区域导致细胞死亡，而周围组织不会受到伤害。这类似于通过放大镜聚焦阳光，只有在放大镜中，能量才足够高，足以灼伤物体。聚焦超声手术可以通过治疗围绕骨骼的神经层和结缔组织来缓解骨转移引起的疼痛。主要的挑战是确保焦点准确地放置在身体内所需的目标上。这很困难，因为骨骼和其他器官会严重扭曲超声束的路径。该奖学金的目的是开发、验证和应用新的计算机模型来模拟声波如何在人体内传播。这些模型将基于理论声学和数值方法的创新进步，并将使用最近才出现的最先进的计算设施。计算机模型将首次准确地预测聚焦超声手术中焦点的位置和骨骼的温度。这将使医生能够仔细计划和优化治疗参数，以消除骨转移引起的疼痛。预计这将提高聚焦超声手术的有效性，减少治疗患者所需的时间，并扩大符合治疗条件的癌症的范围和位置。作为奖学金的一部分，这些模型将使用以前临床治疗的患者数据进行严格验证，并使用旨在模拟人体组织的模体材料进行精心规划的实验室实验。

Cancer is one of the most prevalent diseases in the UK. Each year it accounts for nearly 1 in 3 of all deaths. For patients with late-stage cancer, the cancer cells often spread to other parts of the body. This process is called metastasis, and the secondary tumours that form are called metastases. One of the most common sites for metastases to develop is bones. Around 2 in 3 patients with late-stage breast and prostate cancer, and 1 in 3 with late-stage lung, thyroid, and kidney cancer will develop bone metastases. This can cause debilitating pain, which has a significant impact on patients' quality of life. The most common treatment for reducing pain from bone metastases is external beam radiation therapy. This is aimed at relieving symptoms and controlling the growth of the cancer to improve quality of life, rather than trying to cure the patient (this is known as palliative care). However, as many as 1 in 3 patients treated with radiation therapy do not experience adequate pain relief, and the treatment cannot be repeated due to the toxicity of radiation to healthy tissue inside the body. A very promising alternative therapy for pain palliation is focused ultrasound surgery, also known as high-intensity focused ultrasound or HIFU. This technique works by sending a tightly focused beam of ultrasound into the tissue. At the focus, the ultrasound energy is sufficient to heat the tissue and cause cell death in a very localised region, while the surrounding tissue is not harmed. This is akin to focusing sunlight through a magnifying glass, where only in the focus is the energy high enough to singe an object. Focused ultrasound surgery can be used to alleviate the pain from bone metastases by treating the layer of nerves and connective tissue that surrounds the bone. The major challenge is to ensure the focus is accurately placed at the desired target within the body. This is difficult because bones and other organs can significantly distort the path of the ultrasound beam. The aim of this fellowship is to develop, validate, and apply new computer models to simulate how sound waves travel inside the human body. These models will be based on innovative advances in theoretical acoustics and numerical methods, and will use state-of-the-art computing facilities that have only recently become available. The computer models will allow the position of the focus and the heating of bones during focused ultrasound surgery to be accurately predicted for the first time. This will allow physicians to carefully plan and optimise the treatment parameters to eliminate the pain arising from bone metastases. This is expected to increase the effectiveness of focused ultrasound surgery, reduce the time it takes to treat patients, and extend the range and location of cancers that are eligible for treatment. As part of the fellowship, the models will be rigorously validated using patient data from previous clinical treatments, along with carefully planned laboratory experiments using phantom materials designed to mimic human tissue.