In regard to Vargo et al: "Early Clinical Outcomes for 3 Radiation Techniques for Brain Metastases: Focal Versus Whole-Brain"

Abstract

We read with interest the report by Vargo et al1 comparing the results with whole brain radiotherapy with simultaneous integrated boost (SIB), focal stereotactic intensity modulated radiotherapy, and conventional whole brain radiotherapy. The authors noted a trend toward improved intracranial control with the SIB technique and in the discussion raise the possibility that their focal lesion boost (median 45 Gy over 10-15 fractions) may have been too low. They also cite a lack of dosing guidelines for the SIB approach. In regard to SIB dosing, we previously reported on dosimetric modeling suggesting dose escalation to lesions to 60 Gy/10 fractions with simultaneous treatment of the whole brain to 30 Gy/10 fractions was feasible; the first such report to our knowledge.2 This article also presented preliminary results of a phase I trial, which was later completed, recently reported3 and confirmed the safety of lesional dose escalation to 60 Gy/10 fractions. A pooled analysis has also provided data regarding the feasibility and safety of this approach.4 The SIB approach is now being tested in prospective phase II multi-institutional trials (eg, www.ontario. canadiancancertrials.ca). We share the authors' enthusiasm for this approach and are encouraged by the improved intracranial control rates compared with the alternate strategies reported in their article.