Glossary

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Pituitary Network Association Pituitary Society Up To Date Patient Information Web MD

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• Radiosurgery (Stereotactic Radiosurgery – SRS): a single high dose of focused radiation delivered to a tumor or vascular malformation. Radiosurgery is frequently used to treat brain, pituitary and skull base tumors that are not amenable to complete surgical removal. Radiosurgery can be delivered by a linear accelerator (Trilogy or Novalis) or by the Gamma Knife or Cyberknife; the effectiveness of these different forms of radiosurgery in terms of stopping tumor growth appears to be relatively equal. For tumors that are less than 2 or 3 mm away from the optic nerves or optic chiasm, fractionated (multiple lower dose radiation treatments) stereotactic radiation (SRT) is typically indicated to avoid damage to the optic nerves.
• Radiotherapy (Stereotactic radiotherapy – SRT): multiple doses of radiation therapy given to treat a tumor or vascular malformation. Currently, most radiotherapy is given in focused fashion (stereotactic radiotherapy – SRT) although at times, whole brain radiation is still indicated for some malignant brain tumors such as glioblastoma or metastatic brain tumors.
• Rathke’s Cleft Cyst: a benign cystic collection of fluid that forms in the pituitary gland. These cysts may become symptomatic from headaches, pituitary failure (hypopituitarism) or visual loss and require removal by endonasal surgery. Learn more.
  
• Retro-Sigmoid Craniotomy: a craniotomy behind the ear to reach tumors along the cerebellum and brainstem such as meningiomas and schwannomas. Learn more.