FIGURE 6 from Nanoparticle-mediated Photodynamic Therapy as a Method to Ablate Oral Cavity Squamous Cell Carcinoma in Preclinical Models

Antitumor treatment response to PS-PDT (10 mg/kg, 24 hour DLI, 200 J total) in an orthotopic VX-2 rabbit tumor model. A, Overview of “two-step” PDT treatment scheme in rabbits involving first, surface illumination of the tumor through the overlying skin using an external laser beam (100 J/cm², 100 mW/cm²); and second, interstitial illumination with a diffusing fiber (1 cm, 100 J/cm, 100 mW/cm) inserted into the center of the tumor mass. B, Survival analysis of buccal VX-2 tumors following start of treatment on week 0. Event was tumor volume >3.05 cm³ (humane endpoint). N = 5 tumors (single PS-PDT), 4 tumors (repeat PS-PDT), 3 tumors (drug control), and 3 tumors (light control). Statistics: multiple comparisons of survival curves performed with log-rank tests using Bonferroni correction method for multiple comparison and ⍺ = 0.05. Single PS-PDT versus repeat PS-PDT = ns; Single PS-PDT versus drug control = ns; Single PS-PDT versus light control = *; Repeat PS-PDT versus drug control = *; Repeat PS-PDT versus light control = **. Fold change in tumor volume (C) and representative white light images and CT image reconstructions (D) of orthotopic buccal VX-2 tumors following single PS-PDT treatment on week 0. Fold change in tumor volume (E) and representative white light images and CT image reconstructions (F) following repeat PS-PDT treatments on weeks 0, 1, and 2. For C and E, red arrows indicated occasions of PS-PDT treatment. For D and F, normal anatomy outlined in purple, VX-2 tumor highlighted in green. Images not scaled for size. Additional PS-PDT efficacy data and statistical analysis are provided in Supplementary Table S11.