IMPROVED PROSTATE CANCER STAGING WITH DUAL MODE IMAGING

前列腺癌是美国男性的一个重要健康问题，1999年估计有179，300例新诊断病例，估计有37，000例死亡。 治疗的适当选择在很大程度上取决于临床分期和目前的分期技术是不够的。 111 In-caporumab pendetide（11 IIn- ProstaScint）是一种放射性标记的单克隆抗体，已引入用于评估前列腺癌患者。 拟议研究的目的是使用独特的成像系统开发111 In-ProstaScint的改进定位和定量方法，该成像系统将X射线计算机断层扫描（CT）与单光子发射断层扫描（SPECT）相结合，为前列腺癌患者提供更准确的分期。在这种临床背景下，该项目将集中于三个具体目标：（1）开发一种迭代重建算法，该算法结合了γ射线发射的双能量性质，提供衰减补偿，并考虑到核医学准直器的有限空间分辨率;（2）评价CT/SPECT对前列腺癌患者进行111 In- ProstaScint显像的临床优势;（3）111 In-ProstaScint CT/SPECT图像定量评价与单用SPECT图像目视判读的比较。将开发使用CT/SPECT改善111 In-ProstaScint图像的图像质量和定量准确性的方法，方法包括：（a）将CT校正纳入SPECT重建和定量过程;（B）使用来自配准CT图像的解剖信息增强放射性核素图像。 这项工作的长期目标是开发一种有效的方法，评估原发性疾病和转移进展的前列腺癌使用CT/SPECT成像的肿瘤特异性放射性药物。 我们的目标是提高前列腺癌临床分期的准确性，以便选择适当的治疗方法。 更好地选择将受益于局部放疗、全身激素治疗、进一步手术或甚至初始根治性前列腺切除术的患者，应减少患者不必要的风险，改善治疗结果，并促进用于诊断和治疗前列腺癌的医疗保健支出的成本效益。

Prostate cancer is a significant health problem among men in the United States with an estimated 179,300 new cases being diagnosed and an estimated 37,000 deaths in 1999. Appropriate selection of therapy depends heavily on clinical staging and current staging techniques are inadequate. 111In-capromab pendetide (11IIn- ProstaScint) is a radiolabeled monoclonal antibody that has been introduced to assess patients with prostate cancer. The purpose of the proposed research is to develop improved localization and quantification methods for 111In-ProstaScint using a unique imaging system that combines x-ray computed tomography (CT) with single photon emission tomography (SPECT) to provide more accurate staging for prostate cancer patients. Within this clinical context, the project will focus on three specific aims: (1) Development of an iterative reconstruction algorithm that incorporates the dual-energy nature of the "'In gamma-ray emission, provides attenuation compensation, and accounts for the limited spatial resolution of the nuclear medicine collimator; (2) Assessment of the clinical advantages of CT/SPECT for 111In- ProstaScint imaging of patients with prostate cancer; (3) Comparison of quantitative assessment of 111In-ProstaScint images with CT/SPECT to visual interpretation of the SPECT images alone. Methods using CT/SPECT to improve the image quality and quantitative accuracy of 111In-ProstaScint images will be developed by (a) incorporating corrections from CT into the SPECT reconstruction and quantitation process and (b) augmenting the radionuclide images with anatomical information from the coregistered CT image. The long-term goal of this work is to develop an effective method of assessing primary disease and metastatic progression of prostate cancer using CT/SPECT imaging of tumor-specific radiopharmaceuticals. Our objective is to improve the accuracy of clinical staging of prostate cancer allowing for the selection of appropriate treatment. Better selection of patients who would benefit from localized radiotherapy, systemic hormonal therapy, further surgery, or even initial radical prostatectomy should reduce unnecessary risk to patients, improve therapeutic results, and promote cost- effectiveness of health care spending for diagnosis and treatment of prostate cancer overall.