Efficacy Of The Low Dose Gamma Knife Radiosurgery (gkrs) Treatment For Invasive Giant Prolactinoma

Chain-Fa Su1, Kuan-Pin Chen2, Tsung-Lang Chiu2

1Hualien, Taiwan, Province Of China 2Department of Neurosurgery, Buddhist Tzu Chi General Hospital, Buddhist Tzu Chi University, Hualien, Taiwan

Keywords: pituitary adenoma, radiosurgery, gamma knife, dose planning, prolactinoma

Interactive Manuscript

Ask Questions of this Manuscript:



     Although most pituitary prolactinomas are benign, some are invasive or aggressive.
     The present study reports two cases of invasive giant prolactinoma to demonstrate the effectiveness of tumor size reduction and normalization of hormone after GKRS.
     Case I: A 26-year-old male was identified to have a homogenously enhancing mass at the pituitary fossa with suprasellar extension. The tumor measured about 3 x 3.8 cm in size invaded the sphenoid sinus and the bilateral cavernous sinus with encasement of the internal carotid arteries (ICA).Case 2: A 55-year-old female was referred to our hospital after two incomplete transsphenoidal removal of the pituitary prolactinoma. MR showed an enhanced residual tumor measured about 5.5 x 2.5 cm at the sellar region. The invasiveness of the right cavernous sinus with encasement of the ICA was identified.
     Case 1: A transsphenoidal partial removal of tumor was done and the pathology showed the benign prolactinoma. Blood prolactin level was greater than 200 ng/ml before and after this operation. Patient was referred for the GKRS 3 months after the operation. The treated tumor volume was 21.5 cc and the marginal radiation dose was 12 Gy set at the 50 % isodose line. Case 2:In GKRS, total treated tumor volume was 28 cc and marginal dose 14 Gy was set at the 42 % isodose line.
     In Case 1, the PRL level decreased to 40.6 ng/ml without dopamine agonist medications and 0.87 ng/ml with the use of dostinex 0.5 mg once a week after a 4-year follow up,. The tumor had almost completely disappeared. In Case 2: The blood PRL reduced from the level greater than 1000 ng/ml to the level of 621 ng/ml 6 months after the GKRS. With a 2-year follow-up, the blood PRL turned to normal by the use of dostinex 0.5 mg twice a week. Tumor was markedly reduced and nearly disappeared.
     This is a retrospective study.
      Low Dose (12-14 Gy) Gamma Knife Radiosurgery may be an alternative treatment for invasive giant prolactinoma.
     Longer follow up is needed to prove the true effectiveness.


Project Roles:

C. Su (), K. Chen (), T. Chiu ()