For selective treatment of early gastric cancer,we developed the ICG enhanced Diode-Laser Therapy. This new therapeutic modality is safer, because submucosally injected ICG will be able to protect the muscle layer from injury due to laser beam. The purpose of this animal study was to evaluate penatration time of laser beam and to find sutable concentrarion of ICG solution in this method.
We injected 2ml of ICG solution (0.125, 0.25, 0.5, 1.0, 2.0mg/ml) into submucosal layer and removed it from mucosa and muscle layer_The laser beam with 3mm in diameter was irradiated continuously on the surface of the submucosal layer with the power of 15W. We measured temperature under the submucosal layer and laser power penetrated through it.
With the concentration of more than 0.5mg/ml of ICG solution,penetration time was about 30 seconds and almost all the layer was ablated when laser beam was penetrated. Below 0.5mg/ml, penetration time was shorter and the submucosal layer was ablated incompletely.
In the diode laser ablation therapy for early gastric cancer, submucosal injection of ICG solution with the concentration of more than 0.5mg/ml is recommended, to treat mucosal and submucosal lesions selectively without any injury of muscule layer.
