Fig 5. Kaplan-Meier survival curves are presented for survival assessment.

Groups represent untreated tumors (control), 1% (v/v) microbubble and focused ultrasound exposure (USMB), multi-fraction radiation (XRT), and combined treatments. The USMB treatments were administered twice weekly, and radiation in the XRT and combined treatments were administered in five fractions/week at 2 Gy each over a 3-week period (BED10 = 30 Gy). Endpoints were rabbit death, tumors doubling in size or modified human endpoints. A log-rank test revealed significant differences among the curves (p = 0.002). Pair-wise comparisons were made controlling the false discovery rate to 5%. The mean survival after one week diminished to zero for untreated and USMB treatments, respectively. The XRT group diminished to 19% by the end of the third week. The combined group dropped to 88% after the first week where it remained for all subsequent weeks and was statistically significant compared to all other treatment groups.