Figure 4.

Rate of radionecrosis of any grade (A) and grade IV radionecrosis (B) in 92 brain metastases treated with SRS (red) and 98 brain metastases treated with FSRT (blue). Log-rank p = 0.010 and p = 0.041, respectively. Radionecrosis was defined volumetrically or as tissue diagnosis showing radionecrosis after radiotherapy (see Methods section for details). As radionecrosis grade IV is defined as requiring surgical intervention, all events shown in (B) had histologic proof of radionecrosis. Vertical lines represent censored cases. SRS, Stereotactic radiosurgery; FSRT, Fractionated stereotactic radiotherapy.