Widespread folate receptor expression in pediatric and adolescent solid tumors - opportunity for intraoperative visualization with the novel fluorescent agent pafolacianine

// Ashley C. Dodd 1 , Nitin R. Wadhwani 2 , Alison Lehane 1 , Rom Brown 1 , Kyle L. MacQuarrie 3 , 4 , Seth D. Goldstein 1 , 5 and Timothy B. Lautz 1 , 5 1 Department of Surgery, Ann & Robert H. Lurie Children's Hospital, Chicago, IL 60611, USA 2 Department of Pathology and Laboratory Medicine, Ann & Robert H. Lurie Children's Hospital, Chicago, IL 60611, USA 3 Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA 4 Division of Pediatric Hematology, Oncology, and Stem Cell Transplantation, Ann & Robert H. Lurie Children's Hospital, Chicago, IL 60611, USA 5 Division of Pediatric Surgery, Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA Correspondence to: Timothy B. Lautz, email: TLautz@luriechildrens.org Keywords: folate receptor; fluorescent-guided surgery; pediatric tumors; pafolacianine; RNA sequencing Received: July 15, 2025 Accepted: October 03, 2025 Published: October 16, 2025 Copyright: © 2025 Dodd et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Contemporary fluorescence-guided surgery has evolved principally based on the uses and limitations of the contrast agent indocyanine green (ICG). A second generation of novel fluorescent agents are under development to target specific molecular markers on tumor cells and/or the tumor micro-environment. Pafolacianine, a molecular agent targeting the folate receptor (FR), is the first of these approved for use in adults, but its potential utility in pediatric cancers is unknown. In this study, we performed immunohistochemistry staining on slides obtained from a range of pediatric patients with solid tumors. Slides were stained with antibodies to FRα and FRβ, and fluorescence was quantified. Separately, publicly available RNA sequencing data were queried for both FRα and FRβ expression in various pediatric tumors.