Fig. 6: Simulations of fractionated photoimmunotherapy.
Comparison of simulated PIT with a fixed total light dose (a, b: 15 J/cm2; c, d: 60 J/cm2) delivered in 1 fraction, resulting in tumour escape (a, c), versus delivery in multiple fractions of smaller dose, resulting in tumour control due to immune stimulation from low dose PIT (b, d). On both the phase planes and the C and E time trace plots, the blue circles indicate the pre-treatment initial conditions; red circles the (C, E) values after a PIT fraction; black curves the tumour-effector trajectories after a PIT fraction. e Simulated minimum number of PIT fractions (nfx,min) needed to achieve tumour control for a fixed dose/fraction size for all initial conditions left of the separatrix displayed as a heat map on the C-E phase plane.
