Design study of a two-panel head-and-neck cancer dedicated position emission tomography system

positron emission tomography;head-and-neck cancer;organ specific

Li, Mohan ; Uddin, Rizwan ; Abbaszadeh ; Shiva

关键词: positron emission tomography;    head-and-neck cancer;    organ specific;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/101586/LI-THESIS-2018.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Head and neck cancer (HNC) is collectively a group of cancers that usually begin in mucosal surfaces inside the head and neck. Due to the complex anatomy and vital physiological role of the tumor-involved regions, the goal of HNC treatment is not only to improve survival outcomes but also to preserve organ function. Whole-body (WB) positron emission tomography (PET) has been widely used for HNC diagnosis and treatment, but its low spatial resolution limits the management of HNC. A higher spatial resolution and a better contrast image will allow radiation oncologists to accurately measure the boundaries of tumors, design the planned target volume dose, and thus offer more freedom to choose treatment options such as surgery, radiation therapy, chemotherapy and targeted therapy. To achieve a better management of HNC, this dissertation proposes a HNC dedicated PET system, which is supposed to replace the dedicated protocol in hospitals. The performance of a proposed system is studied using a Monte Carlo simulation. The noise equivalent count rate of the dedicated system is 9.3 kcps at 5.7 kBq/cm3, and it increases to 10.5 kcps at 5.7 kBq/cm3 with a lead shielding. The photon sensitivity is 0.83% for a point source placed at the field of view (FOV) center. With a 2-mm full width at half maximum (FWHM) depth-of-interaction resolution, the system achieves 1 mm orthogonal-panel and 1.5 mm parallel-panel spatial resolution, and a 2-mm diameter hot rod is visible. Multiple scattering events are recovered and the entire FOV has a relatively uniform improvement of sensitivity. Signal- to-noise ratio and contrast-to-noise ratio of the reconstructed image improve 41.4% and 29.2% respectively after incorporating recovered multiple scattering events. Compared with a commercial WB PET system (GE Discovery MI), the proposed dedicated system shows an 830% improvement of noise equivalent count rate, a 36.1% improvement of photon coincidence sensitivity and a better spatial resolution and lesion visualization capability. Further hardware-level work such as detector module design and characterization are on-going to validate these initial results.