Investigation of marking procedure of markings in deep-seated organs by means of proton beam therapy

To obtain, an accurate outline of a tumor lesion in deep-seated organs with X-ray images in proton therapy, an implantation procedure of markers to determine the margins of the lesion has been developed. Nonradioactive Au grains were used as the markers and produced sufficiently clear images. The procedure consists of implanting the markers with a specially designed injector for endoscopic, palpative and intraoperative approaches to the lesions, which was performed without any adverse effects. Due to application of this procedure, the accuracy of treatment planning and pinpointing the site of the treatment field has improved greatly. (author)