{"doi":"10.3390/ph17060685","title":"PET Imaging of Neurofibromatosis Type 1 with a Fluorine-18 Labeled Tryptophan Radiotracer","abstract":"Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder. Plexiform neurofibromas (PNFs) are benign tumors commonly formed in patients with NF1. PNFs have a high incidence of developing into malignant peripheral nerve sheath tumors (MPNSTs) with a 5-year survival rate of only 30%. Therefore, the accurate diagnosis and differentiation of MPNSTs from benign PNFs are critical to patient management. We studied a fluorine-18 labeled tryptophan positron emission tomography (PET) radiotracer, 1-(2-[18F]fluoroethyl)-L-tryptophan (L-[18F]FETrp), to detect NF1-associated tumors in an animal model. An ex vivo biodistribution study of L-[18F]FETrp showed a similar tracer distribution and kinetics between the wild-type and triple mutant mice with the highest uptake in the pancreas. Bone uptake was stable. Brain uptake was low during the 90-min uptake period. Static PET imaging at 60 min post-injection showed L-[18F]FETrp had a comparable tumor uptake with [1⁸F]fluorodeoxyglucose (FDG). However, L-[18F]FETrp showed a significantly higher tumor-to-brain ratio than FDG (n = 4, p < 0.05). Sixty-minute-long dynamic PET scans using the two radiotracers showed similar kidney, liver, and lung kinetics. A dysregulated tryptophan metabolism in NF1 mice was further confirmed using immunohistostaining. L-[18F]FETrp is warranted to further investigate differentiating malignant NF1 tumors from benign PNFs. The study may reveal the tryptophan–kynurenine pathway as a therapeutic target for treating NF1.","journal":"Pharmaceuticals","year":2024,"id":480243,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9691,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1302801,"name":"Erik Stauff","orcid":null,"position":1,"is_corresponding":false},{"id":1319855,"name":"Shriya Boyapati","orcid":null,"position":2,"is_corresponding":false},{"id":425992,"name":"Sigrid A. Langhans","orcid":"0000-0003-4695-7468","position":3,"is_corresponding":false},{"id":1302443,"name":"Wenqi Xu","orcid":"0009-0007-7192-4656","position":4,"is_corresponding":false},{"id":531932,"name":"Sokratis Makrogiannis","orcid":"0000-0003-0316-3529","position":5,"is_corresponding":false},{"id":1124857,"name":"Uchenna Okorie","orcid":null,"position":6,"is_corresponding":false},{"id":950234,"name":"Azubuike Okorie","orcid":"0000-0002-1348-3166","position":7,"is_corresponding":false},{"id":1287781,"name":"Vinay Kandula","orcid":"0000-0002-0212-0183","position":8,"is_corresponding":false},{"id":610002,"name":"Heidi H. Kecskemethy","orcid":"0000-0002-4508-184X","position":9,"is_corresponding":false},{"id":1287782,"name":"Rahul Nikam","orcid":"0000-0002-7049-3264","position":10,"is_corresponding":false},{"id":1287780,"name":"Lauren W. Averill","orcid":"0000-0003-0734-9611","position":11,"is_corresponding":false},{"id":340492,"name":"Thomas H. Shaffer","orcid":"0000-0003-1757-8506","position":12,"is_corresponding":false},{"id":425987,"name":"Xuyi Yue","orcid":"0000-0002-3783-6392","position":0,"is_corresponding":true}],"reference_count":50,"raw_metadata":null,"created_at":"2026-07-19T02:06:58.305365Z","pmid":"38931352","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}