ROLE OF PET/CT IN RADIOTHERAPY TREATMENT PLANNING

This chapter focuses on the rationale, target validation, dose prescription verification and evaluation, and recent clinical achievements in the field of integrating positron emission tomography imaging into radiotherapy treatment planning. Application of functional imaging to radiotherapy is a rapidly expanding field with the development of new modalities and techniques. Functional imaging of positron emission tomography in conjunction with radiotherapy provides new avenues toward the clinical application of dose painting as a new radiotherapy strategy delivering optimized dose redistribution according to the functional imaging information to further improve tumor control. New biological imaging methodologies mainly based on positron emission tomography/computed tomography, magnetic resonance imaging, and magnetic resonance spectroscopy imaging, in conjunction with radiotherapy, make dose painting possible. It can be used to draw a three-dimensional map of radiobiological relevant parameters as its inherent potential to trace the real target volume, consisting of tumor cells that require a therapeutic dose to control the disease. Positron emission tomography/computed tomography is outstanding and widely used in daily clinical practice. It offers molecular biological information on the tumor microenvironment in addition to anatomical imaging and shows significant biological heterogeneity of tumors, such as metabolism, proliferation, hypoxia, radioresistance cell density, and perfusion.