[7 fractionated cyberknife radiotherapy for giant skull metastasis: a case report]

This is a report on the experience of using stereotactic radiotherapy for a large symptomatic metastatic skull tumor. The stereotactic radiotherapy was delivered in 7 fractions using the Cyberknife and produced excellent therapeutic results. This case concerns a 75-year-old female. Nineteen months after uterine cancer surgery, the patient demonstrated metastasis to the mediastinum lymph node and a tumor at the parietal bone tumor but was still undergoing observation. An increase of the parietal bone tumor became evident and the appearance of right hemiplegia, aphasia, and cognitive dysfunction caused her to consult this hospital. We observed a large 236 cm3 tumor spread over the subcutaneous tissue of the superior sagittal sinus, pressing the brain out of the dura mater and causing bone destruction. As a result of our findings, we began stereotactic Cyberknife radiotherapy delivered in 7 fractions. At the follow up visit one month after the treatment, the image of the tumor had already decreased, and after three months it was confirmed that the image of the tumor had disappeared. The patient's symptoms ameliorated rapidly. As a result, the patient has returned to an independent home-lifestyle, with amelioration of her quality-of-life defects. Six months after irradiation, there is no evidence of tumor regrowth or complications such as dermatopathy, cerebral edema, or necrosis. Cyberknife radiotherapy could shorten the treatment period and result in a reduction of the amount of irradiation to unaffected parts of the brain. In this case, though the tumor had spread widely in the subcutaneous tissue, the exposure doses were delivered at 2Gy/time and could be limited to under 70Gy. It is thought that Cyberknife radiotherapy will become one of the key treatments to help improve quality of life when treating symptomatic metastatic tumors.