The Problematic PET: Using CT Albumin Tracer to Resect Suspicious Lymph Nodes Found on PET Scan in Pediatric Oncology Patients

Background: Management of small lymph nodes or lesions in dense nodal basins found on Positron Emission Tomography (PET) scans can be challenging to identify, access and locate intraoperatively. Herein we describe the first reported case series utilizing pre-operative CT-guided radionuclide-tagged macro-aggregated albumin (TC 99m MAA) for localization and resection of extra-pulmonary PET-avid lymph nodes in pediatric cancer patients. Methods: Pediatric cancer patients (<21 years) who underwent pre-operative TC 99m MAA localization of suspicious lymph nodes were identified and retrospectively reviewed.Results: Ten procedures were performed on 10 children at our institution from 2017 to 2021. Median age was 14 [13, 18]; 70% were male. Primary tumor type was variable. Lymph nodes were in various nodal basins including the axilla, groin, neck, popliteal fossa, retroperitoneum, and mediastinum. Three patients underwent resection of both pulmonary and extra-pulmonary lesions during the same procedure. Median node size was 15 mm (range: 10 mm-23 cm). In 60.0% of patients the localized lymph nodes of concern were non-palpable at the time of operation. In 90% of the patient, biopsy findings changed the course of disease management.Conclusion: Pre-operative labeling with TC 99m MAA is a safe and effective technique to facilitate the localization, biopsy, and resection of suspicious lymph nodes found on PET scans in pediatric cancer patients that are located in dense nodal basins. This technique enables accurate resection of small, concerning lymph nodes that might otherwise be difficult to operatively identify and excise; the resultant information can affect the staging and further treatment of these patients. Level of evidence: IV.& COPY; 2022 Elsevier Inc. All rights reserved.