F18-FDG PET imaging as a diagnostic tool for immune checkpoint inhibitor–associated acute kidney injury
Shruti Gupta, Olivia Green‐Lingren, Sudhir Bhimaniya, Aleksandra A. Krokhmal, Heather A. Jacene, Marlies Ostermann, Sugama Chicklore, Ben Sprangers, Christophe M. Deroose, Sandra M. Herrmann, Sophia L. Wells, Sarah Allison Kaunfer, Jessica L. Ortega, Clara García-Carro, Michael S. Bold, Kevin L. Chen, Meghan E. Sise, Pedram Heidari, Wai Lun Will Pak, Meghan Lee, Pazit Beckerman, Yael Eshet, Raymond K. Hsu, Miguel Hernandez Pampaloni, Arash Rashidi, Norbert Avril, Vicki Donley, Zain Mithani, Russ Kuker, Muhammad O. Awiwi, Mindy X. Wang, Sujal I. Shah, Michael Weintraub, Heiko Schöder, Raad Chowdhury, Harish Seethapathy, Kerry L. Reynolds, María José Soler, Ala Abudayyeh, Ilya Glezerman, David E. Leaf
Abstract
To the Editor: Immune checkpoint inhibitors (ICIs), anticancer agents that enhance antitumor response, can cause autoimmune toxicities, including ICI-associated acute kidney injury (ICI-AKI).The most common histopathologic lesion in patients with ICI-AKI is acute tubulointerstitial nephritis (ATIN); however, a definitive diagnosis of ATIN requires a kidney biopsy (1).This represents a frequently encountered clinical challenge for providers, as AKI is very common among cancer patients, many of whom have contraindications to kidney biopsy (e.g., solitary kidney, therapeutic anticoagulation).Accordingly, noninvasive methods of diagnosing ICI-AKI are urgently needed, as treatment involves glucocorticoids and discontinuation of potentially life-saving immunotherapy.Case reports and one case series explored the utility of 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography-computed tomography (F18-FDG PET-CT) for diagnosing ICI-AKI and reported mixed findings (2, 3); however, these studies did not have clear inclusion and exclusion criteria to carefully phenotype the patients, did not use rigorous techniques to minimize sampling error, and, most importantly, in some cases did not include a control group.We sought to address these key knowledge gaps and define the role of F18-FDG PET-CT in diagnosing ICI-AKI.We used data from a retrospective, multicenter cohort study of 429 patients with ICI-AKI treated at 30 sites across 10 countries (1).Patients were diagnosed with ICI-AKI between 2012 and 2023 and had either biopsy-proven or clinically adjudicated ICI-AKI (Supplemental Table 1; []