Successful radiotherapy for local control of progressively increasing metastasis of gastrointestinal stromal tumor.

Gastrointestinal stromal tumors (GISTs) are known to be poorly responsive to conventional chemotherapy and historically considered resistant to radiotherapy. In the past the mainstay of GIST treatment was surgery, but the introduction of tyrosine kinase inhibitors (TKIs) imatinib and sunitinib marked the beginning of a new era in the treatment of GIST patients. To date, radiotherapy for GIST has not been administered in clinical practice except for limited palliative settings and there are no clear data on the administration of radiotherapy, alone or in combination with TKIs, with a purely cytoreductive intent. We describe the clinical case of a 48-year-old woman with metastatic GIST treated with external radiotherapy in a critical supraclavicular tumor localization progressively increasing in size with several symptoms and not responsive to systemic TKI therapies. We obtained an initial shrinkage of the mass and subsequent stabilization with an immediate and clear clinical benefit. Although the historical medical literature considered GISTs resistant to radiation therapy, our clinical case suggests this treatment may be appropriate in selected patients.