PTT in dual-flank A20 lymphoma model. (A) Schematic illustration and schedule of the experimental model. Tumor-inhibition efficacy was monitored for 16 days after photothermal ablation combined immunotherapy. Local and systemic immunotherapies were evaluated from primary and secondary tumors. (B) Tumor growth curves of primary tumor (treated). Inset graph focuses on difference between PTT and RT. (C) Tumor growth of secondary tumor (untreated). Inset graph focuses on difference between PTT and RT. (D) Representative resected primary (p) and secondary (s) tumors for each experimental group. Scale bar, 1 cm. Data were obtained from at least 6 independent samples. Data are shown as means ± standard errors of the mean. *P < .05, **P < .01, ***P < .001 (2-tailed paired t test). i.t., intratumoral; Treg, regulatory T cell.