The Evolving Role of PET- Based Novel Quantitative Techniques in the Interventional Radiology Procedures of the Liver Siavash Mehdizadeh Seraj, MD a , Cyrus Ayubcha, BA a , Mahdi Zirakchian Zadeh, MD, MHM a,b , Abass Alavi, MD, MD(Hon), PhD(Hon), DSc(Hon) a, *, Stephen J. Hunt, MD, PhD, DABR a INTRODUCTION Interventional radiology (IR) procedures have revo- lutionized the treatment of cancer and given birth to the emerging field of interventional oncology (IO) as the fourth pillar of cancer care. These procedures have been used both as palliative and curative treatments in a variety of malignancies. 1–4 Several established IO treatment options, such as radiofrequency ablation (RFA), transarterial chemoembolization (TACE), transarterial radioem- bolization (TARE), and high-intensity focused ultra- sonography, have demonstrated efficacy in treating hepatic tumors. These noninvasive pro- cedures often improve the clinical outcome of patients with primary hepatic tumors, as well as metastatic hepatic tumors. 2 However, an individu- alized assessment is required to determine the optimal treatment plan for a patient. Moreover, ac- curate tools are needed to monitor the response to treatment to evaluate the efficacy of the treatment and patient’s subsequent management planning. Fluorodeoxyglucose (FDG)-PET imaging was first conceived in the early 1970s by researchers at the University of Pennsylvania as a means of noninvasively measuring brain’s function and metabolism. 5 Initially, FDG-PET was predomi- nantly used for the early detection and assessment of various neurologic disorders. 6,7 Soon thereafter, the application of this imaging modality was expanded as FDG-PET became a prominent tech- nique for diagnosis, staging, treatment response monitoring, and prognosis of different malig- nancies. 8 An advantage of FDG-PET is the ability to quantify the magnitude of radiotracer uptake, which is representative of disease burden. A a Department of Radiology, Hospital of University of Pennsylvania, 3400 Spruce street, Philadelphia, PA 19104, USA; b Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Boulevard, Philadel- phia, PA 19104, USA * Corresponding author. 3400 Spruce Street, Philadelphia, PA 19104. E-mail address: abass.alavi@uphs.upenn.edu KEYWORDS  FDG-PET  Quantification  Dual time-point imaging  Interventional radiology  Liver  Malignancy KEY POINTS  Fluorodeoxyglucose (FDG)-PET/computed tomography has an expanding role in the interventional radiology procedures of the liver.  The quantitative analyses of FDG-PET have shown the ability to assess treatment response and prognosis.  The accuracy of PET quantification can be enhanced by adopting novel quantitative techniques that can better reflect global disease burden. PET Clin 14 (2019) 419–425 https://doi.org/10.1016/j.cpet.2019.06.004 1556-8598/19/Ó 2019 Elsevier Inc. All rights reserved. pet.theclinics.com