Özet:

OBJECTIVE: The goal of this study is to evaluate the safety and efficacy of CyberKnife image-guided radiosurgery for lesions immediately adjacent to the orbital structures. MATERIAL and METHODS: We applied fractionated stereotactic radiotherapy with CyberKnife (Accuray Incorporated, Sunnyvale, CA) to six patients with lacrimal gland tumor who were admitted the period of May 2009-June 2011 to our clinic. There were three women, three men. The median age 33 year (range,16-51 year). Pathological subtypes were adenoid cystic carcinoma in five patients, while the remaining one was pleomorphic adenoma. Before treatment planing, thin-slice CT and MRI images were obtained. These images were transferred to the CyberKnife treatment-planning workstation and target volumes and critical structures were delineated manually. Treatment was delivered in 3-8 fractions up to mean total dose of 30 Gy (range, 23.5-40 Gy). The prescription dose was defined at a mean isodose of 83% (range, 72–92%). RESULTS: The mean follow-up period was 9.5 months (range, 4-26 months). It was determined that two patients had complete response, three patient had partial response in follow up period. The tumors remained stable in the other two patients. All patients had visual evaluation done during follow up period It wasn't determined decreasing or loss of vision function in four patients who had full vision function. CONCLUSION: Fractionated stereotactic radiotherapy with CyberKnife is an effective treatment alternative for tumors that located in orbital region as lacrimal gland tumors, which maximize the dose to the target while limiting the dose within tolerable doses for the radiosensitive orbital structures. Protecting visual function while decreasing of tumor size or preventing of tumor progression, and short treatment duration are advantages of this technique. Furthermore, longer follow-up studies and more number of cases are needed.

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