International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2017
External Validity of a Risk Stratification Score Predicting Early Distant Brain Failure and Salvage Whole Brain Radiation Therapy After Stereotactic Radiosurgery for Brain Metastases.
A scoring system using pretreatment factors was recently published for predicting the risk of early (≤6 months) distant brain failure (DBF) and salvage whole brain radiation therapy (WBRT) after stereotactic radiosurgery (SRS) alone. Four risk factors were identified: (1) lack of prior WBRT; (2) melanoma or breast histologic features; (3) multiple brain metastases; and (4) total volume of brain metastases <1.3 cm3, with each factor assigned 1 point. The purpose of this study was to assess the validity of this scoring system and its appropriateness for clinical use in an independent external patient population. ⋯ The 3-level Emory risk score was shown to not be externally valid, but the model was able to stratify between 2 levels (LR and not-LR [combined IR and HR]) for early (≤6 months) DBF. These results reinforce the importance of validating predictive models in independent cohorts. Further refinement of this scoring system with molecular information and in additional contemporary patient populations is warranted.