How do you stereotactically treat brain metastases greater than 3 cm +/- additional brain mets?  

It is my impression that for brain metastases >3 cm it may be preferable to deliver fractionated SRT versus the RTOG dose of 15 Gy SRS, if WBRT is omitted. If delivering fractionated SRT, is there a current optimal scheme? I am familiar with 5 Gy x 5 to a 1 mm PTV, but am also aware that some are giving 6Gy x 5 (EQD2 >=35 Gy) or 8Gy x 3. Is there a current "right dose" or range of dose fractionation schemes? 

In a related question, what is the best approach when there is a met >3cm with perhaps 2 or 3 smaller distributed mets <= 2 cm? Hypofractionate all or SRT the larger lesion and SRS the smaller ones?



Answer from: Radiation Oncologist at Academic Institution