Imaging Response to Ensartinib in Concurrent Papillary and Anaplastic Thyroid Carcinoma With ALK Rearrangement

Clin Nucl Med. 2026 Aug 1;51(8):e631-e632. doi: 10.1097/RLU.0000000000006437. Epub 2026 May 11.

Abstract

A 67-year-old woman with coexisting papillary thyroid carcinoma (PTC) and anaplastic thyroid carcinoma (ATC) harbored an ALK rearrangement on FISH. Despite surgery and 2 courses of 131 I treatments, 18 F-FDG PET/CT showed an intensely avid right lower-neck mass extending into the superior mediastinum. The patient was considered radioiodine-refractory (RAIR) and started ensartinib (225 mg once daily). CT at 3 months showed marked regression, with sustained disease control at 12 months. This case illustrates an objective imaging response to ALK-directed therapy in RAIR thyroid carcinoma.

Keywords: ALK; anaplastic thyroid carcinoma; ensartinib; papillary thyroid carcinoma.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Anaplastic Lymphoma Kinase
  • Carcinoma, Papillary / diagnostic imaging
  • Carcinoma, Papillary / drug therapy
  • Female
  • Gene Rearrangement*
  • Humans
  • Positron Emission Tomography Computed Tomography*
  • Receptor Protein-Tyrosine Kinases* / genetics
  • Thyroid Cancer, Papillary / diagnostic imaging
  • Thyroid Carcinoma, Anaplastic* / diagnostic imaging
  • Thyroid Carcinoma, Anaplastic* / drug therapy
  • Thyroid Carcinoma, Anaplastic* / genetics
  • Thyroid Neoplasms* / diagnostic imaging
  • Thyroid Neoplasms* / drug therapy
  • Thyroid Neoplasms* / genetics

Substances

  • Anaplastic Lymphoma Kinase
  • ALK protein, human
  • Receptor Protein-Tyrosine Kinases