Figure 4.

Whole tumor R2* changes during room air (AIR) versus oxygen (O2) breathing. Room air breathing increased R2* values within VX2 tumors at baseline due to increased paramagnetic susceptibility from deoxyHb. a) Over time, rabbits treated with radioembolization (n=12 tumors, 6 rabbits) had reductions in R2* values during room air breathing at 1 and 2 weeks post-radioembolization while b) untreated control rabbits (n=6 tumors, 3/5 rabbits) demonstrated a stable to slightly increased R2* during room air breathing at 2 weeks. c) Tumor growth rate was higher in untreated control rabbits and while the gas-challenge signal was maintained in control rabbits, tumors treated with radioembolization had a drop in this signal suggesting decreased tumor hypoxia.