Task Group 174 Report: Utilization of [¹⁸F]Fluorodeoxyglucose Positron Emission Tomography ([¹⁸F]FDG‐PET) in Radiation Therapy

Abstract

The use of positron emission tomography (PET) in radiation therapy (RT) is rapidly increasing in the areas of staging, segmentation, treatment planning, and response assessment. The most common radiotracer is 18F‐fluorodeoxyglucose ([18F]FDG), a glucose analog with demonstrated efficacy in cancer diagnosis and staging. However, diagnosis and RT planning are different endeavors with unique requirements, and very little literature is available for guiding physicists and clinicians in the utilization of [18F]FDG‐PET in RT. The two goals of this report are to educate and provide recommendations. The report provides background and education on current PET imaging systems, PET tracers, intensity quantification, and current utilization in RT (staging, segmentation, image registration, treatment planning, and therapy response assessment). Recommendations are provided on acceptance testing, annual and monthly quality assurance, scanning protocols to ensure consistency between interpatient scans and intrapatient longitudinal scans, reporting of patient and scan parameters in literature, requirements for incorporation of [18F]FDG‐PET in treatment planning systems, and image registration. The recommendations provided here are minimum requirements and are not meant to cover all aspects of the use of [18F]FDG‐PET for RT.

Machine learning in quantitative PET: A review of attenuation correction and low-count image reconstruction methods

“…Reducing administered activity can also help patients undergoing radiation therapy who have multiple serial PET scans as part of their pretreatment and radiotherapy response evaluation [42,43]. Considerations should be given to the need for optimal imaging and minimization of patient dose in order to reduce the potential risk of secondary cancer [44]. Secondly, shortened scan time is beneficial for minimizing patient motion as well as potentially increasing patient throughput.…”

Effect of uncertainties in quantitative 18F‐FDG PET/CT imaging feedback for intratumoral dose‐response assessment and dose painting by number

“…These findings suggest that it is critically important to maintain the consistency of the PET image acquisitions for the quantitative response assessment, as suggested by many previous studies. [55][56][57][58][59] In clinical applications, TI variation within 5 min could be needed to maintain the SUV 0 uncertainty (1 SD) within 2.41% and DRM uncertainty within 3.35%. This uncertainty was relatively small compared with those caused by PET imaging PVE and tumor PET/CT DIR.…”

PET/CT acceptance testing and quality assurance: Executive summary of AAPM Task Group 126 Report

“…This document provides guidance for quality control (QC) of the PET subsystem of most clinical PET/CTs operating in any mode, for example, two‐dimensional (2D) or three‐dimensional (3D) data acquisition, resolution recovery, or time‐of‐flight, and aims to enable direct comparisons among various scanner models and manufacturers. We refer the reader to other resources for guidance on evaluating the CT subsystem of a clinical PET/CT 12–14 and on the use of PET/CT during radiation therapy 15,16 . All tests in this report were developed by qualified medical physicists, as defined by AAPM professional Policy 17 “Scope of Practice of Clinical Medical Physics,” 17 who have extensive knowledge and experience with the numerous commercially available PET platforms.…”

“…We refer the reader to other resources for guidance on evaluating the CT subsystem of a clinical PET/CT [12][13][14] and on the use of PET/CT during radiation therapy. 15,16 All tests in this report were developed by qualified medical physicists, as defined by AAPM professional Policy 17 "Scope of Practice of Clinical Medical Physics," 17 who have extensive knowledge and experience with the numerous commercially available PET platforms. The report generated by TG 126 "PET/CT Acceptance Testing and Quality Assurance" was reviewed by the AAPM Nuclear Medicine Subcommittee (NMSC), Imaging Physics Committee (IPC), Science Council (SC), and Executive Committee (EXCM) and published in October 2019.…”