The CyberKnife (CK), a medical device for stereotactic radiotherapy, is composed of a linear accelerator (Linac), a robot manipulator and a TLS (Target locating System). This system has been applied for the treatment of cranial diseases (intracranial tumors, arteriovenous malformations). In addition, this system has been used for the treatment of head and neck tumors (nasal cavity, paranasal sinus, nasopharynx, mesopharynx, and oral floor), and spinal lesions. Between November 2002 and December 2005, 6 patients with nasal cavity and paranasal sinus malignant tumor were treated using this system. The primary lesions were located in the nasal cavity, ethmoidal sinus, frontal sinus, sphenoidal sinus, maxillar sinus, and intracranial lesion. Histopathologically, these 6 cases were categorized as squamous cell carcinoma, olfactory neuroblastoma, malignant malanoma, papillary carcinoma (metastasis of thyroid cancer), and cylindrical cell carcinoma. The average CK dose was 23 Gy. Among the 6 cases, 3 cases were CR and the others were PR. The response rate (CR×PR) was 100%. Adverse effects, such as olfactory anesthesia, pigmentation and skin inflammation were seen in 3 cases. Optic nerve dysfunction was not seen. The Gamma Knife (GK) requires a frame to fix the patients head, but CK does not. This allows the CK to deliver the radiation to a wider area than the GK. In addition, because the CK can deliver highly conformal radiation to lesions with a high accuracy, there is a significant reduction in the adverse effects. CK could be effective for the treatment of malignant tumors of the nasal cavity and paranasal sinus without affecting the function of these tissues, while also improving the QOL of the patients.
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