Investigation of Newly Prepared Biodegradable 32P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy
68Ga-3PRGD2 micro-PET-CT imaging during 32P brachytherapy and tumour volume measurement using a caliper. (a) The 68Ga-3PRGD2 micro-PET/CT transverse images of nude mice bearing glioma on days 0.5, 2, 4, 8, and 16 after intratumoural implantation of radioactive 32P-CP-PLGA seeds (A) and nonradioactive P-CP-PLGA seeds (B). (b) Tumour volume was measured using a caliper every other day after intratumoural administration of 32P-CP-PLGA seeds, 32P-CP colloid, and nonradioactive P-CP-PLGA seed. (c) Tumour uptake of 68Ga-3PRGD2 was quantified based on micro-PET/CT imaging and compared between radioactive and nonradioactive seeds group. Tumour uptake (%ID/g) of 68Ga-3PRGD2 was significantly different at the same points. In 32P-CP-PLGA seeds group, distribution heterogeneity of 68Ga-3PRGD2 was observed on day 2 and was even significant and toroidal on day 4, with slight accumulation of radiotracer on day 8 and being almost negative on day 16. The distribution of 68Ga-3PRGD2 was uniform at 8 days after nonradioactive seed implantation. Internal absence was observed on day 16, reflecting ulcer formation. # means tumour uptake of 68Ga-3PRGD2 in P-CP-PLGA seeds group was significantly lower than 32P-CP-PLGA seeds group () while means tumour uptake of 68Ga-3PRGD2 in P-CP-PLGA seeds group was significantly higher than 32P-CP-PLGA seeds group (). The white arrows refer to tumors.