MicroCT imaging and in vivo temperature elevations in implanted prostatic tumors in laser photothermal therapy using gold nanorods

Abstract

In this study, in vivo animal experiments are erformed on implanted enograph rostatic tumors in nude mice to investigate enhanced laser energy absorption in the tumors by an intratumoral injection of old nanorod solutions. in vivo temperature mapping of the tumors during laser hotothermal therapy has shown the easibility of elevating tumor temperatures higher than 0 C using only 0.1 ml nanorod solution and a low laser irradiance of 1.6 W/cm2 incident on the tumor surface. The temperature rofile suggests that normal tumor tissue still absorbs some amount of the laser energy without nanorod resence; however, the injected nanorods ensure that almost all the laser energy is absorbed and confined to the targeted tumors. The inverse relationship between the temperature elevations and the tumor size implies a relatively uniform spreading of the nanorods to the entire tumor, which is also shown by microcomputed tomography (microCT) imaging analyses. The feasibility of detecting 50 OD old nanorod solution injected to the tumors is demonstrated via a high resolution microCT imaging system. ompared to other nanostructures, the old nanorods used in this study do not accumulate surrounding the injection site. The relatively uniform deposition of the nanorods in the tumors observed by the microCT scans can be helpful in uture study in simplifying theoretical simulation of temperature elevations in tumors during laser hotothermal therapy