Synapse - [(18)F]TFB PET/CT misses intense [(124)I]iodine-avid metastases after redifferentiation therapy in metastatic thyroid cancer

[(18)F]TFB PET/CT misses intense [(124)I]iodine-avid metastases after redifferentiation therapy in metastatic thyroid cancer Journal Article

Authors:	Backhaus, P.; Pentlow, K. S.; Ho, A. L.; Mauguen, A.; Fagin, J. A.; Pillarsetty, N. V. K.; Lyashchenko, S. K.; Burnazi, E.; Ghossein, R. A.; Chhabra, S.; Abusamra, M.; Larson, S. M.; Schöder, H.; O’Donoghue, J.; Weber, W.; Grewal, R. K.
Article Title:	[(18)F]TFB PET/CT misses intense [(124)I]iodine-avid metastases after redifferentiation therapy in metastatic thyroid cancer
Abstract:	Background: Fluorine 18-labelled tetrafluoroborate ([18F]TFB) is a substrate for the sodium/iodide symporter. In thyroid cancer, [18F]TFB-PET/CT may be an alternative to iodine imaging to evaluate the extent of disease, eligibility for radioiodine treatment, and success of redifferentiation therapies. We report the results of a pilot study to determine tumor uptake of [18F]TFB and compare its properties to [124I]IodinePET/CT in patients with metastatic thyroid cancer. Methods: Five patients were included in a prospective study. All patients received PET/CT 1 h after injection of 356 ± 12 MBq [18F]TFB and were given 230 ± 9 MBq [124I]Iodine orally on the same day, followed by PET/CT after 48 h. Before redifferentiation therapy, patients underwent an additional baseline [124I]Iodine PET/CT. Cases were analyzed by two board-certified specialists. Detection rates and Spearman correlation for [18F]TFB and [124I]Iodine were calculated. Results: Three patients had poorly differentiated thyroid cancer and received trametinib in a redifferentiation trial. Two patients had papillary thyroid cancer and did not receive redifferentiation therapy. Of the 33 lesions seen before/without redifferentiation therapy, 19 (58%) were visible on [18F]TFB and 30 (91%) on [124I]Iodine imaging. In the patients who underwent redifferentiation therapy, 48 lesions were newly seen on [124I]Iodine PET/CT with a median SUVmax of 3.3 (range, 0.4–285.0). All of these lesions were [18F]TFB-negative. Conclusion: [18F]TFB failed to predict radioactive iodine uptake in patients with poorly differentiated thyroid cancer who underwent redifferentiation therapy with trametinib. It is unclear whether such discrepancies may also occur in other redifferentiation therapies or may even be encountered in redifferentiation-naïve thyroid cancer. Trial registration number: NCT03196518, registered on June 22, 2017. © The Author(s) 2024.
Keywords:	adult; clinical article; middle aged; unclassified drug; prospective study; quality control; metastasis; image analysis; cancer therapy; lung metastasis; correlation coefficient; radioactive iodine; pilot study; dosimetry; fluorodeoxyglucose f 18; imaging; iodine 124; thyroid cancer; cholecystectomy; liver hemangioma; gynecomastia; thyroid papillary carcinoma; recombinant thyrotropin; pet/ct; radiochemistry; cerebellum tumor; trametinib; human; male; female; article; redifferentiation therapy; redifferentiation; positron emission tomography-computed tomography; ecog performance status; [<sup>124</sup>i]iodine; [<sup>18</sup>f]tfb; tetrafluoroborate
Journal Title:	EJNMMI Research
Volume:	14
ISSN:	2191-219X
Publisher:	Springer
Date Published:	2024-10-08
Start Page:	91
Language:	English
DOI:	10.1186/s13550-024-01138-x
PROVIDER:	scopus
PMCID:	PMC11461403
PUBMED:	39377970
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85205966825&doi=10.1186%2fs13550-024-01138-x&partnerID=40&md5=2f36b48419da456d9aacad89f5f83e48
Notes:	Article -- MSK Cancer Center Support Grant (P30 CA008748) acknowledged in PubMed and PDF -- MSK corresponding author is Ravinder Grewal -- Source: Scopus