Oncology PET: Lung Cancer

Cheon, Gi Jeong

Abstract

Computed tomography (CT) is the most widely used imaging modality for cancer. CT offers good spatial resolution and low levels of statistical noise, resulting in anatomical images of high quality. However, CT detects only anatomical changes associated with the disease, functional imaging approaches are needed to image the underlying metabolic characteristics. Functional imaging using positron emission tomography (PET) using 2-[18F]fluoro-2-deoxy-D-glucose (FDG) is currently recognized as a useful imaging modality in oncology, providing valuable functional metabolic information for tumor diagnosis, staging, detecting recurrence, and monitoring response of therapy. However, PET lacks anatomical information and has a limitation in localization of small lesions and accurate definition of lesion extent and relationship with adjacent structures. To overcome the limitations of both modalities, hardware-based imaging co-registration is designed to acquire anatometabolic imaging. The advantage of fusion PET/CT includes accurate co-registration of anatomical and functional images, precise patient positioning, low noise PET attenuation correction and shortening the scan time by CT transmission. In thoracic malignant diseases, PET can allow the early and improved diagnosis by the metabolic information, and therefore better planning of the therapeutic approach. In addition, visual comparison of PET and CT improves interpretation of FDG-PET alone by precise localization or CT alone by providing metabolic information. Functional PET imaging can affect the planning target volume of radiation therapy by the precise localization and characterization of malignant lesions. In some times, combined PET/CT can guide the biopsy site of multiple equivocal lesions. I review the current roles of PET in diagnosis, staging, and therapeutic implication of patients with lung cancers