18F-FDG PET/CT Monitoring of Tumor Response to Tyrosine Kinase Inhibitors and Alkylating Drugs in an SDH-Deficient GIST

Clin Nucl Med. 2021 Oct 1;46(10):e515-e517. doi: 10.1097/RLU.0000000000003615.


Succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumors (GISTs) are associated with loss of function of SDH complex and represent 5% to 7.5% of GISTs. SDH-deficient GISTs usually develop in the stomach of children and young adults, and could be part of Carney triad or Carney-Stratakis syndromes including paraganglioma. SDH-deficient GISTs are often indolent despite the high rate of distant metastasis, and overall unresponsive to tyrosine kinase inhibitors. However, epigenetic inactivation of MGMT leads to potential effectiveness of alkylating agents. We report the 18F-FDG PET/CT results for monitoring response to TKI and alkylating drugs in a patient with refractory SDHB-deficient GIST.

MeSH terms

  • Alkylating Agents
  • Child
  • Fluorodeoxyglucose F18
  • Gastrointestinal Stromal Tumors* / diagnostic imaging
  • Gastrointestinal Stromal Tumors* / drug therapy
  • Gastrointestinal Stromal Tumors* / genetics
  • Humans
  • Mutation
  • Pharmaceutical Preparations*
  • Positron Emission Tomography Computed Tomography
  • Protein Kinase Inhibitors / therapeutic use
  • Succinate Dehydrogenase / genetics
  • Young Adult


  • Alkylating Agents
  • Pharmaceutical Preparations
  • Protein Kinase Inhibitors
  • Fluorodeoxyglucose F18
  • Succinate Dehydrogenase