Efficacy of Positron Emission Tomography/Computed Tomography in staging of cancers

Introduction

In the last few decades, CT was regarded as the gold standard imaging method in in oncology as it was used for the initial staging, evaluation of tumors after treatment, and follow up of those patients diagnosed with cancer. However, this technique of conventional imaging was not always efficient when it comes to differentiating between the malignant and benign tumors (Wechalekar et al, 2005). PET which is a molecular imaging technique that is non invasive uses a number of radiolabeled compounds and visualizes the metabolic differences between the tissues and it therefore depicts the functional status of any suspicious lesions. The history of PET can be traced back to the 1970s but it was approved for limited use in the United States in 1998 in oncological clinical practice (Oriuchi et al, 2006).

PET was developed based on the observation that malignant cells were associated with increased glycolic rates as well as increased uptake of cellular glucose. F-fluorodeoxyglucose (F-FDG) is mostly used in visualizing the biochemical procedure and can also be used to quantify the glucose metabolic rates ( Kopoor et al, 2004).The PET technology also has several limitations. Most of the anatomic structures are poorly depicted and this makes it difficult for one to precisely localize the tumor lesions. In addition, the FDG accumulates in a number of normal tissues and this makes it difficult for one to interpret the images especially when the neoplasm is close to those organs with uptake of physiological FDG (Cook et al, 1999).

Attachment:- Efficacy-of-PETCT.doc