Interesting ImagesSegmentation in Non–Small Cell Lung Tumors Using 18F-FDG PET/CT Tips and RulesJiménez Londoño, Germán Andrés MD∗; Pérez-Beteta, Julián PhD†; Bosque, Jesús J. PhD†; Honguero-Martinez, Antonio Fancisco PhD‡; García Vicente, Ana Maria PhD∗Author Information From the ∗Nuclear Medicine Department, Hospital General Universitario de Ciudad Real, Ciudad Real †Instituto de Matemática Aplicada a la Ciencia y la Ingeniería, Universidad de Castilla-La Mancha, Castille-La Mancha ‡Surgery Department, Hospital General Universitario de Albacete, Albacete, Spain. Received for publication January 23, 2020; revision accepted May 8, 2020. Conflicts of interest and sources of funding: none declared. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. Correspondence to: Germán Andrés Jiménez Londoño, MD, General Universitario de Ciudad Real, Calle Obispo Rafael Torija, s/n, 13005 Ciudad Real, Ciudad Real, Spain. E-mail: [email protected]. Clinical Nuclear Medicine: November 2020 - Volume 45 - Issue 11 - p e477-e482 doi: 10.1097/RLU.0000000000003166 Buy Metrics Abstract The assessment of tumor parameters derived from 18F-FDG PET/CT in oncology provides valuable information in non–small cell lung cancer. A proper segmentation should delineate tumor with high accuracy, being the most important step to measure metabolic parameters. However, there is still no consensus about the optimal methodology. Additionally, some clinical conditions inherently tied to tumor and imaging can limit the proper tumor delineation. We present some practical cases that represent different aspects to consider during segmentation of primary non–small cell lung cancer by using 18F-FDG-PET/CT and some possible solutions to tackle with the most common limitations in clinical practice. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.