Experimental studies of stereotactic laser balloon hyperthermic treatment

Abstract

Background and Objective The hyperthermic treatment of small malignant brain tumors in basal ganglia and other eloquent cortical areas was investigated with a stereotactic Nd:YAG laser balloon unit. Study Design/Materials and Methods An Ultra Line™ fiber (Hermaeus Laser Sonics, CA) was inserted into a 6 F silicone balloon catheter, which caused the laser beam to be directed 80° laterally. The balloon was inflated with physiologic saline to make the tumor tissue surrounding the laser fiber hypoxic. The hypoxia enhances the thermal effect on the tumor. The laser power was set at 5 watts (W) and a computer, programmed with specific parameters using feedback control was used to maintain the tissue 10 mm distant from the laser fiber at a temperature of 45°C. Forty five minutes of hyperthermic treatment was applied to an implanted subcutaneous glioma in a rat. Results/Conclusion The thermally induced damaged in the tumor appeared as a fan‐shape lesion extending at a 100° angle from the laser beam axis. The entire tumor could be treated by rotating the laser fiber in the balloon catheter. Lasers Surg. Med. 20:195–201, 1997. © 1997 Wiley‐Liss, Inc.