Basic principles of radiotherapy in ophtalmic oncology

Ophtalmologic Radiation Oncology concerns intra ocular tumors, orbital tumors and eyelid tumors. In these locations, tumors are often close to normal critical tissues, increasing the risk of radiation toxicities. Basic principles of ophthalmic radiotherapy are not really different from radiotherapy of others organs. They are based on a precise description of the tumor volume, knowledge of potential tumor local or regional extension, knowledge of tissue biological radiosensitivity for tumors and the surrounding normal tissues. Based on these features, treatment modalities (radiation treatment length and fractionation) are determined to fulfill the aims of medical curative intents: good local control with acceptable toxicities or the aims of medical palliative intents: to relief with minimal toxicities. Many types of radiation therapy can be used for ophthalmic tumors: brachytherapy, orthovoltage radiotherapy, conformal therapy with photons and electrons including intensity modulated radiation therapy, protontherapy, and the use of specific devices such as CyberKnife and Tomotherapy. All of these techniques have their advantages and their disadvantages, leading the radiation oncologist to make a choice depending on the tumor site and characteristics.