INTRACAVITRY HYPERTHERMIA & RADIATN OF ESOPHAGEAL CANCER

热疗治疗癌症的研究主要是为了 表面肿瘤，已被发现是有效的，特别是在 与放疗或化疗相结合。加热深层肿瘤 从技术上讲，使用外部微波场或无线电频场 难度很大，因为这些油田的渗透深度有限。打在胸口 在这一领域，体外超声技术由于 骨骼和空气界面的反射。空洞中的某些肿瘤部位 内脏和空洞可以用腔内技术治疗。那里 估计将有10,900例新病例和9,800例食道死亡 1991年美国的癌症。尽管协议有所改进， 目前涉及手术、放疗和化疗的治疗方法还没有 在过去的几十年里显著提高了存活率。 最近来自中国和日本的临床报告显示肿瘤有很大改善 综合热疗患者的疗效和存活率 和外部辐射。在这些研究中，射频和微波加热 研究采用了多种技术。我们的目标是通过以下方式改善治疗结果 腔内照射和热疗与外照射相结合。 腔内放射具有定位辐射的优点，而且 由于高辐射剂量而导致溃疡。体温过高可以 增强辐射效应，从而降低所需剂量。 因此，假设腔内放射和 热疗可改善治疗效果。 在这项研究中，我们建议进行I/II阶段试验，以调查 腔内热疗和放射治疗的疗效和安全性。我们有 研制出一种小巧灵活的食道多腔聚氨酯样机 管子，可容纳六路温度传感器或 在外围有辐射种子，在中央有微波天线 管子。我们正在开发和建造各种偶极天线，以 加热不同长度的食道肿瘤。根据供暖模式 通过热像仪获得，我们将选择合适的天线并研究 动物模型在一小时治疗期间的温度变化。 这一信息对于治疗控制至关重要，因为肿瘤和正常 如果没有相当大的风险，组织温度很难测量 病人。结果应该使我们能够估计组织和肿瘤 温度由多腔管中测量的温度决定。这个 将使用生物热传递方程来计算温度分布 适用于各种正常和肿瘤血流状态。理论上的 预测结果将与静态体模结果(无血流)进行比较。 利用食道内的结果，目的是加热食道 到43摄氏度以上的粘膜。动物研究将揭示 组织温度与多腔管中测得的温度一致。这些 理论和动物结果对于人类阶段I/II是必要的 审判。

Hyperthermia for cancer treatment has been investigated mostly for superficial tumors and has been found to be efficacious, especially in combination with radiation or chemotherapy. Heating deep-seated tumors with external microwave or radio frequency fields is technically very difficult because the fields have limited penetration depths. In the chest area, external ultrasound techniques have little application due to the reflections at bone and air interfaces. Certain tumor sites in hollow viscera and cavities can be treated with intracavity techniques. There will be an estimated 10,900 new cases and 9,800 deaths from esophageal cancer in the U.S.A. during 1991. Despite improvements in protocols, current therapies involving surgery, radiation and chemotherapy have not significantly improved the survival rate in the last several decades. Recent clinical reports from China and Japan show much improved tumor response and survival rate in patients treated with combined hyperthermia and external radiation. In these studies, RF and microwave heating techniques were used. Our goal is to improve the treatment results by combining intracavitary radiation and hyperthermia with external radiation. Intracavitary radiation has the advantage of localizing radiation but also causes ulceration due to high radiation dosage. Hyperthermia can potentiate the radiation effects and therefore reduces the required dose. Thus, the hypothesis is that combined intracavitary radiation and hyperthermia improve the treatment outcome. In this study, we propose to conduct Phase I/II trials to investigate the efficacy and safety of intracavitary hyperthermia and radiation. We have developed a small and flexible prototype esophageal multilumen polyurethane tube, which can accommodate six channels of temperature sensors or radiation seeds at the periphery, and a microwave antenna in the center of the tube. We are developing and constructing various dipole antennas to heat esophageal tumors at various lengths. Based on the heating patterns obtained by thermography, we will select appropriate antennas and study the temperature variations in animal models over a one hour treatment period. This information is essential for treatment control since tumor and normal tissue temperatures are difficult to measure without considerable risk to the patient. The results should enable us to estimate the tissue and tumor temperature by the temperatures measured in the multilumen tube. The bioheat transfer equation will be used to calculate temperature profiles for various normal and tumor blood flow conditions. Theoretical predictions will be compared with static phantom results (no blood flow) and with results inside the esophagus, the aim is to heat the esophageal mucosa to above 43o C. The animal studies will reveal the correlation of tissue temperature with that measured in the multilumen tube. These theoretical and animal results are necessary for the human Phase I/II trials.