Dosimetric factors associated with pituitary function after Gamma Knife Surgery (GKS) of pituitary adenomas

Gianluisa Sicignano, Marco Losa, Antonella Del Vecchio, Giovanni Mauro Cattaneo, Piero Picozzi, Angelo Bolognesi, Pietro Mortini, Riccardo Calandrino

Research output: Contribution to journalArticlepeer-review


Background and purpose: Gamma Knife Surgery (GKS) can be an adjunctive option to surgery in the case of pituitary adenomas. The effect of dosimetric variables on the incidence of new anterior pituitary deficits after GKS requires better definition. Materials and methods: This retrospective study considered 130 patients with a follow up after GKS >6 months. The diagnosis was nonfunctioning pituitary adenoma (NFPA) in 68 patients and secreting pituitary adenoma (SPA) in 62 patients. Median margin dose was 15/25 Gy for NFPA and SPA, respectively. The endocrinological median follow-up was 60 months. Hypopituitarism was defined as a new pituitary deficit in (at least) one of the three hormonal axes (hypogonadism, hypothyroidism and hypoadrenalism). The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses. Results: Sixteen patients (12.3%) showed a new pituitary deficit in one or more axes. Multivariate analysis confirmed that the mean dose to the stalk/pituitary and the amount of healthy tissue within the high dose region were strong independent predictors of pituitary dysfunction; their best cut-off values were around 15.7 Gy, 7.3 Gy and 1.4 cm 3, respectively. Conclusions: Our data showed a dose-dependent incidence of new hormonal deficits after GKS for pituitary adenoma. During planning definition, the risk of hypopituitarism could be reduced using the outlined safe dose-volume values.

Original languageEnglish
Pages (from-to)119-124
Number of pages6
JournalRadiotherapy and Oncology
Issue number1
Publication statusPublished - Jul 2012


  • Dosimetric predictors
  • Gamma Knife Surgery
  • Hypopituitarism
  • Pituitary adenoma

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Hematology


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