The use of 18F-FDG PET/CT for radiotherapy treatment planning in non-small cell lung cancer: a mini-review

Abstract

: In the past decades, the technical achievements in radiotherapy treatment planning and delivery, such as the use of intensity-modulated radiotherapy or the use of image-guided radiotherapy, alongside with the significant developments in molecular imaging and especially the use of positron-emission tomography (PET) have significantly improved radiotherapy treatment precision. In non-small cell lung cancer (NSCLC), the use of 18F-fluoro-desoxy-glucose (18F-FDG) positron-emission tomography/computed tomography (18F-FDG-PET/CT) has a high accuracy for diagnostic workup, staging and response assessment but has been also implemented to optimize target volume concepts in NSCLC with high precision. These advances led, in the recent years, to an increased tumor control and improved outcomes. Especially in the context of emerging systemic treatments, such as immune checkpoint blockades (ICBs), the prevention of unnecessary irradiation of the lymphatic system might be very important. In the past years, several prospective randomized studies have been performed, aiming to optimize, standardize and develop new concepts in the target volume delineation especially in locally advanced NSCLC using different approaches. While the PET-Plan trial used a uniform target volume reduction based on the 18F-FDG-PET/CT signal in the experimental arm, the PET boost trial and the RTOG 1106 used the 18F-FDG-PET/CT information to define an additional boost volume for dose escalation. Within this mini-review, we provide an overview on the role of 18F-FDG-PET/CT, the challenges and the benefits, in radiotherapy of NSCLC.