Investigation of Newly Prepared Biodegradable 32P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy. (29th April 2018)

• Record Type: Journal Article
• Authors: Shao, Guoqiang; Wang, Yuebing; Liu, Xianzhong; Zhao, Meili; Song, Jinhua; Huang, Peiling; Wang, Feng; Wang, Zizheng
• Other Names: Schirrmacher Ralf Academic Editor.
• Is Part Of: Contrast media & molecular imaging. Volume 2018(2018)
• Publication Date: 2018-04-29
• Subjects: Diagnostic imaging -- Periodicals; Magnetic resonance imaging -- Periodicals; Contrast media (Diagnostic imaging) -- Periodicals; Contrast Media -- Periodicals; Diagnostic Imaging -- Periodicals; Substances de contraste -- Périodiques; Diagnostics moléculaires -- Périodiques; Imagerie médicale; Substance de contraste; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.0754
• DOI: 10.1155/2018/2630480
• Languages: English
• ISSNs: 1555-4309

Abstract

Abstract : 32 P high-dose rate brachytherapy allows high-dose radiation delivery to target lesions with less damage to adjacent tissues. The early evaluation of its therapeutic effect on tumours is vital for the optimization of treatment regimes. The most commonly used 32 P-CP colloid tends to leak with blind therapeutic area after intratumour injection. We prepared 32 P-chromic phosphate-polylactide-co-glycolide ( 32 P-CP-PLGA) seeds with biodegradable PLGA as a framework and investigated their characteristics in vitro and in vivo . We also evaluated the therapeutic effect of 32 P-CP-PLGA brachytherapy for glioma with the integrin α v β 3-targeted radiotracer 68 Ga-3PRGD2 . 32 P-CP-PLGA seeds (seed group, SG, 185 MBq) and 32 P-CP colloid (colloid group, CG, 18.5 MBq) were implanted or injected into human glioma xenografts in nude mice. Scanning electron microscopy (SEM) of the seeds, micro-SPECT imaging, and biodistribution studies were performed at different time points. The tumour volume was measured using a caliper, and 68 Ga-3PRGD2 micro-PET-CT imaging was performed to evaluate the therapeutic effect after 32 P intratumour administration. The delayed release of 32 P-CP was observed with biodegradation of vehicle PLGA. Intratumoural effective half-life of 32 P-CP in the SG (13.3 ± 0.3 ) d was longer than that in the CG (10.4 ± 0.3 ) d (P < 0.05 ), with liver appearance in the CG on SPECT. A radioactivity gradient developed inside the tumour in the SG, as confirmed by micro-SPECT and SEM. Tumour uptake of 68 Ga-3PRGD2 displayed a significant increase on day 0.5 in the SG and decreased earlier (on day 2) than the volume reduction (on day 8). Thus, 32 P-CP-PLGA seeds, controlling the release of entrapped 32 P-CP particles, are promising for glioma brachytherapy, and 68 Ga-3PRGD2 imaging shows potential for early response evaluation of 32 P-CP-PLGA seeds brachytherapy.