Multidrug resistant gastrointestinal stromal tumor with multiple metastases to the skin and subcutaneous soft tissue: A case report and review of literature

Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms which account for less than 1% of all gastrointestinal malignancies. Of all the extra-abdominal metastases of GIST, superficial soft tissue metastases are the rarest. Previous reports have found success with sunitinib in imatinib-resistant GIST, but we report a certain wild-type KIT mutation GIST with cutaneous and subcutaneous metastasis that was unresponsive to multiple tyrosine kinase inhibitor (TKI) treatments. This case illustrates that knowing the specific type of KIT mutations may uncover resistance of certain GIST's to TKIs, necessitating more targeted and alternative therapy.     

Modifiable risk factors for acute skin toxicity in adjuvant breast radiotherapy: Dosimetric analysis and review of the literature

Acute skin toxicity in adjuvant breast radiation can be reduced with modern radiotherapy (RT) techniques. However, having reviewed the literature, we found no dosimetric constraint for acute skin toxicity that would be applicable to modern RT planning. This study aimed to identify dosimetric factors that are associated with higher rates of acute skin toxicity. A retrospective review was carried out including women who received adjuvant forward-planned intensity-modulated radiotherapy (IMRT) after breast-conserving surgery. Acute skin toxicity grade was prospectively recorded. A total of 131 patients were analyzed. On multivariate analysis, the V105%?>?30?cc (p?=?0.013) and the use of conventional fractionation (CF) (p?=?0.001) were statistically significant for acute skin toxicity. On literature review, current quantitative dosimetric parameters that have shown statistical significance include a V107%?>?3?cc in hypofractionation (HF), V107%?>?9?cc in CF, treated volume 110%?>?5.13%, and V107%?>?28.6%. There is little evidence on the predictive value of clinically applicable dosimetric factors in acute skin toxicity. Given the recent improvements in RT planning, we would consider a V107% or a V110% too high a dosimetric value to be useful for the majority of patients. We have shown that a V105% of greater than 30?cc is significantly associated with acute skin toxicity, controlling for other variables. We suggest that this is currently the most useful modifiable parameter available to reduce skin toxicity and is applicable to modern RT planning. We also suggest that consideration be given to hypofractionated schedules to further reduce acute skin toxicity.