Repositionable Gynecological Applicator for Image-guided Radiosurgery (IGRS) and Image-guided Radiation Therapy (IGRT) for Localized Treatment of Gynecological Tumors

摘要

A method and apparatus for precisely reproducing the position of a vaginal cylinder in relation to a patient to ensure that a planned radiation dose can be delivered with high precision to the intended treatment target volumes. In order to properly define the treatment volume, a vaginal cylinder with proper diameter is inserted into the patient's vagina. This invention addresses two potential errors: one, the incorrect vaginal cylinder position in relation to the radiation beams, and second, the inconsistent positional correlation between the vaginal cylinder and the patient's body. These two geometric errors will cause dosimetric errors. The present invention provides a method and apparatus for minimizing the geometric error and dosimetric error associated with conventional external beam radiation therapy or radiosurgery used in treating gynecological tumors. First a treatment plan is carried out to determine the treatment target volume. Second, treatment delivery is carried out by using an image-guided system to locate the position of the vaginal cylinder and comparing it relative to the treatment delivery system coordinate system and the patient's coordinate system. The displacement in the position of the vaginal cylinder from the treatment plan is corrected by calculating the transformation matrix and entering the resulting value into a position adjusting assembly. The position adjusting assembly adjusts the vaginal cylinder to exactly reproduce its location relative to the patient's coordinate system. This ensures that the image-guided system locates the precise radiation delivery position and that the radiation dose is delivered precisely to the treatment target volume.