Gamma Knife surgery for pituitary adenomas: factors related to radiological and endocrine outcomes Clinical article
ABSTRACT Gamma Knife surgery (GKS) is a common treatment for recurrent or residual pituitary adenomas. This study evaluates a large cohort of patients with a pituitary adenoma to characterize factors related to endocrine remission, control of tumor growth, and development of pituitary deficiency.
A total of 418 patients who underwent GKS with a minimum follow-up of 6 months (median 31 months) and for whom there was complete follow-up were evaluated. Statistical analysis was performed to evaluate for significant factors (p < 0.05) related to treatment outcomes.
In patients with a secretory pituitary adenoma, the median time to endocrine remission was 48.9 months. The tumor margin radiation dose was inversely correlated with time to endocrine remission. Smaller adenoma volume correlated with improved endocrine remission in those with secretory adenomas. Cessation of pituitary suppressive medications at the time of GKS had a trend toward statistical significance in regard to influencing endocrine remission. In 90.3% of patients there was tumor control. A higher margin radiation dose significantly affected control of adenoma growth. New onset of a pituitary hormone deficiency following GKS was seen in 24.4% of patients. Treatment with pituitary hormone suppressive medication at the time of GKS, a prior craniotomy, and larger adenoma volume at the time of radiosurgery were significantly related to loss of pituitary function.
Smaller adenoma volume improves the probability of endocrine remission and lowers the risk of new pituitary hormone deficiency with GKS. A higher margin dose offers a greater chance of endocrine remission and control of tumor growth.
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ABSTRACT: The efficacy of gamma knife surgery on Cushing's disease is not well known to date. In most reported cases of Cushing's disease treated with gamma knife, the area to be irradiated was determined with computed tomography or pneumoencephalography. We report two cases of recurrent pituitary-dependent Cushing's disease treated with gamma knife using stereotactic magnetic resonance imaging (MRI). Recurrent microadenomas were visualized as hypointense areas using gadolinium-enhanced MRI after two transsphenoidal surgeries in both cases. The doses of irradiation given were 35 Gy and 20 Gy to the margin of the tumors, and less than 8 Gy and 21 Gy to the optic apparatus and cranial nerves in the cavernous sinus, respectively. Both patients had clinical remission with normal serum cortisol and adrenocorticotrophic hormone levels, during 2-year follow-up after radiosurgery, without endocrinologic deficiency or neurologic deterioration. Gamma knife surgery can be an alternative therapy for Cushing's disease when pituitary adenomas are apart from the optic apparatus and can be visualized clearly by MRI, even if tumors are recurrent after microsurgery.Surgical Neurology 03/1995; 43(2):170-5; discussion 175-6. DOI:10.3171/2013.7.JNS13217 · 1.67 Impact Factor
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ABSTRACT: To assess the effects of radiosurgery (RS) on the radiological and hormonal control and its toxicity in the treatment of pituitary adenomas. Retrospective analysis of 42 patients out of the first 48 consecutive patients with pituitary adenomas treated with RS between 1999 and 2008 with a 6 months minimum follow-up. RS was delivered with Gamma Knife as a primary or adjuvant treatment. There were 14 patients with non-secretory adenomas and, among functioning adenomas, 9 were prolactinomas, 9 were adrenocorticotropic hormone-secreting and 10 were growth hormone-secreting tumors. Hormonal control was defined as hormonal response (decline of more than 50% from the pre-RS levels) and hormonal normalization. Radiological control was defined as stasis or shrinkage of the tumor. Hypopituitarism and visual deficit were the morbidity outcomes. Hypopituitarism was defined as the initiation of any hormone replacement therapy and visual deficit as loss of visual acuity or visual field after RS. The median follow-up was 42 months (6-109 months). The median dose was 12,5 Gy (9 - 15 Gy) and 20 Gy (12 - 28 Gy) for non-secretory and secretory adenomas, respectively. Tumor growth was controlled in 98% (41 in 42) of the cases and tumor shrinkage occurred in 10% (4 in 42) of the cases. The 3-year actuarial rate of hormonal control and normalization were 62,4% and 37,6%, respectively, and the 5-year actuarial rate were 81,2% and 55,4%, respectively. The median latency period for hormonal control and normalization was, respectively, 15 and 18 months. On univariate analysis, there were no relationships between median dose or tumoral volume and hormonal control or normalization. There were no patients with visual deficit and 1 patient had hypopituitarism after RS. RS is an effective and safe therapeutic option in the management of selected patients with pituitary adenomas. The short latency of the radiation response, the highly acceptable radiological and hormonal control and absence of complications at this early follow-up are consistent with literature.Radiation Oncology 11/2010; 5(1):109. DOI:10.1186/1748-717X-5-109 · 2.36 Impact Factor
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ABSTRACT: Objectives: Pituitary adenoma represents the most frequent tumour encountered in the sellar region. We have proposed to review the principles of diagnosis and treatments and to analyze their standard protocol of approaching pituitary lesions. Material and method: We have retrospectively analyzed the cases of pituitary adenoma between Jan 2006 and Dec 2010, we studied presenting symptoms, hormonal status, local extension, surgical approach, tumor histology, type of resection, tumor volume, cavernous sinus invasion, surgical corridors, recurrence rate, intra operative and postoperative complications Results: 72 patients were included in the study, with no significant difference between sexes, the pathology was dominated by pituitary macro adenomas in 47 cases, regarding the hormonal status 51.3% were non secreting pituitary adenomas, the rate of operability in our series was 65.2%, the surgical indication has been given mainly by the hormonal status and involvement of the optic apparatus which in our series was 51%, the invasion of the cavernous sinus has been appreciated according the Knosp criteria (7) and grade 3 and 4 was present in 44% of the cases. The most used surgical approach was the pterional approach in 83% and the remaining 17% by the transsphenoidal approach. The most frequent surgical corridor was represented by the prechiasmatic route in 54%, gross total resection was achieved in 51%. The most frequent postoperative complication encountered in our series was represented from systemic complication the meningitis 13%, as for endocrine complication it was represented by transitory diabetes insipidus in 23.4% and SIADH in 4.2% (2 cases). The follow up at 3 months showed no cases of early recurrence, from the group of patient with STR 6 were sent to radiotherapy. The follow up at 1 year has comprised 3 deaths, 3 cases of hydrocephalus treated with ventriculoperitoneal derivation, 19 cases were with no imagistic or clinical symptoms of tumour and 22 presented with imagistic evidence of stable residual tumour with no clinical symptoms.