Figure 6.

Effect of Weekend Interruptions during RT on Tumor Control and the Tumor-Immune Ecosystem after Treatment

(A) Model-predicted tumor responses to fractionation schemes with and without weekend breaks, depending on the functional degree of tumor-associated vascularity (B) and the recruitment rate of effector cells in response to tumor burden (r). Radiation was delivered to a total dose of 50 Gy in 25 fractions at 2 Gy/day, (standard; S) 5 days/week, or (consecutive; C) 7 days/week. Tumor control (TC) (blue) and progressive disease (red) refer to tumor eradication and escape after treatment, respectively.

(B) Amount of effector cells at the end of treatment (a.t.) and overall radiation-induced effector cells for tumors with different functional degrees of tumor-associated vascularity (B), and treated with the standard (S) or consecutive (C) fractionation scheme.

(C) Dependence of the therapeutic success rate with $0.40\le r\le 0.55$ and $0.1\le B\le 0.5$ on the intrinsic proliferation rate of tumor cells (${\lambda }_M$) and fractionation protocol of RT. Model simulations were performed with $\eta =8.0\times {10}^5$ cells day⁻¹, ${\lambda }_M=1.25$ 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].