Figure 3

Typical MRI scan changes in prolactinomas adenoma. Coronal T1-weighted postcontrast MRI scan at left and right, obtained in Patient 2, a 27-year-old woman who presented with prolactinomas adenomas and amenorrhea-galactorrhea 4 years before undergoing MASEP GKRS. An asymmetrically enhancing mass lesion is seen in the sella turcia with extension to bilateral internal carotid artery. Patient 2's serum prolactin level was 183.7 ng/ml. The patient was treated with MASEP GKRS twice because of the huge volume of the mass. The second MASEP GKRS was performed 1 year after the first one. The tumor was treated separately with the lower and upper part in order to protect the optic chiasma. MRI was performed for treatment planning. 25 Gy defined to the 50% isodose line is used to cover the lower part of the pituitary tumor in the first treatment, and 18 Gy defined to the 50% isodose line is used to cover the upper part of the pituitary tumor in the second time.