Metastatic GIST

 All pt with advanced GIST--> check for KIT and PDGFRA mutations. 70-80% have either of these.

KIT exon 9---> needs higher dose of imatinib 800 mg daily, 

exon 11 standard dose

PDGFRA also responds to imatinib

SDH deficient--> resistant to imatinib. Other options--> sorafenib, vandetinib, pazopanib, regorafenib, temodar