Figure 2.

Effect of Functional Tumor Vascularization Extent and Strength of Radiation-Induced Immunity on Tumor Response to Radiotherapy

(A) Model-predicted tumor responses to RT depending on tumor-associated vascularity (B) and the recruitment rate of effector cells in response to tumor burden (r).

(B–D) Time evolution of tumor radius and effector cells during and after RT for parameter combinations marked in (A).

(E) Dependence of the therapeutic success rate with $0.40\le r\le 0.55$ and $0.1\le B\le 0.7$ on the strength of radiation-induced antitumor immune responses (η) and the intrinsic proliferation rate of tumor cells (${\lambda }_M$). Radiation was delivered to a total dose of 50 Gy in 25 daily fractions at 2 Gy per day, 5 days per week. Tumor control (TC) (blue) and progressive disease (red) refer to tumor eradication and escape after treatment, respectively. Model simulations were performed with $\eta =8.0\times {10}^5$ cells day⁻¹, ${\lambda }_M=1.15$ day⁻¹, and a tumor size at time of RT equal to $R=15$ mm, unless indicated otherwise.

The remaining parameter values were as in Table S1 [Parameter values considered in model simulations].