Stereotactic Radiosurgery For Pituitary Adenomas Research Articles

Stereotactic radiosurgery for pituitary adenoma

Stereotactic radiosurgery for pituitary adenoma

Effect of distance from target on hypopituitarism after stereotactic radiosurgery for pituitary adenomas.

Delayed hypopituitarism is the most common complication after stereotactic radiosurgery (SRS) for pituitary adenomas. The aim of this study was to investigate the relationship between the distance from the hypothalamic-pituitary axis to the treatment target and anterior pituitary function preservation after SRS. Between 2007 and 2020, consecutive adult patients who underwent single-session SRS for non-functioning or hormone-secreting pituitary adenomas with ≥ 6months of follow-up were included. Distance measurements between hypothalamic-pituitary axis structures and the SRS target volume were quantified on MRI. The primary outcome was anterior pituitary function preservation. Outcomes were compared using multivariable regression and area under the receiver operator characteristic curve (AUROC) analyses. The study cohort comprised 224 patients, who were categorized by preservation (n = 168) and no preservation (n = 56) of anterior pituitary function after SRS. The mean and median clinical follow-up durations were 53.7 (38.0) and 46.0 (17.0-75.0) months, respectively. Independent predictors of anterior pituitary function preservation were a greater distance between the center of the pituitary gland and center of the SRS target [OR 1.101 (1.000-1.213), p = 0.050], and a shorter clinical follow-up duration [OR 0.985 (0.977-0.993), p < 0.0001]. The adjusted AUROC for the distance from the center of the pituitary gland and center of the SRS target in predicting anterior pituitary function preservation was 0.595. The sensitivity, specificity, positive predictive value and negative predictive value in predicting anterior pituitary function preservation at the optimal cut-off distance of 15mm were 30.0, 88.0, 89.9 and 26.2%, respectively. Greater distance between the normal pituitary gland and the SRS target is associated with anterior pituitary function preservation and increasing this distance should be a goal of adenoma resection. Larger prospective, multi-center studies are necessary to corroborate this finding and establish the effects of distance on hypopituitarism after SRS for pituitary adenomas.

Stereotactic Radiosurgery for pituitary adenomas: A review of literature.

Stereotactic radiosurgery (SRS) is a choice of treatment for pituitary adenomas (PA), particularly for residual or recurrent disease, apart from surgery. It has a progression free survival and endocrine remission rate comparable to surgery, with fewer side effects, making it an ideal tool for dealing with PA. In this review, we have discussed the role of SRS for primary as well as post-operative residual/ recurrent PA, and have assessed its safety and outcomes.

Internal carotid artery stenosis and risk of cerebrovascular ischemia following stereotactic radiosurgery for recurrent or residual pituitary adenomas.

To evaluate the incidence of internal carotid artery (ICA) stenosis and cerebrovascular accident in a series of patients treated with stereotactic radiosurgery (SRS) for recurrent or residual pituitary adenoma. All patients treated with single fraction SRS in our institution for recurrent or residual non-functioning-, growth hormone- and ACTH-secreting pituitary adenomas were retrospectively identified and reviewed. A comprehensive literature review to identify studies reporting on ICA steno-occlusive disease following SRS for pituitary adenomas and compare the risks of carotid stenosis and ischemic stroke in the SRS treated group to the general population figures. 528 patients [312 women and 216 men; median age at SRS 46years old (range 12-80years)] treated with SRS at our institution met study inclusion criteria. Mean clinical and radiologic follow-ups were 68.87 (SD ± 43.29) and 55.99months (SD ± 38.03), respectively, and there were no clinically evident cerebral ischemic events noted. Asymptomatic, post-SRS, ICA stenosis occurred in two patients. A total of eight patients with ICA steno-occlusive disease following pituitary adenoma radiosurgery have been reported. Two of them suffered from ischemic stroke with however excellent recovery. As compared to the general population, SRS for pituitary adenomas does not seem to confer appreciable increased risk for ICA steno-occlusive disease and ischemic stroke. However, post-SRS radiation vessel injuries do occur and physicians should be aware about this rare event. Prompt identification and management according to current guidelines are essential to prevent ischemic strokes.

Role of Stereotactic Radiosurgery in Pituitary Adenomas.

Pituitary adenomas are one of the common indications for gamma knife radiosurgery. Gamma knife enables one to deliver a very high radiation dose to the target in a single fraction. Due to steep radiation fall out of Gamma Knife, the adjacent visual apparatus gets minimal radiation. The aim of stereotactic radiosurgery for pituitary adenomas is to stop tumor growth, normalize hormonal hypersecretion, preserve pituitary function, and protect important surrounding structures. Surgery is the treatment modality of choice in the management of pituitary adenomas and gamma knife radiosurgery is restricted for residual or recurrent lesions only. The acceptable marginal dose for non-functional adenomas is 12 Gy. Control rates varies from 76-87% at 10 years are described in non-functional pituitary adenomas. In functional adenomas, to achieve hormonal remission a higher marginal dose up to 25 Gy is needed. However, primary gamma knife radiosurgery is needed in some situations - for instance, when the patient is unfit for surgery due to various reasons or surgical difficulties like the presence of kissing carotids.

Analysis of Circulating Endostatin and Vascular Endothelial Growth Factor in Patients with Pituitary Adenoma Treated by Stereotactic Radiosurgery: A Preliminary Study.

BackgroundThe purpose of this study was to investigate plasma levels of endostatin and vascular endothelial growth factor (VEGF) in normal subjects and in patients with pituitary adenoma and to evaluate change in these levels following stereotactic radiosurgery (SRS) for pituitary adenoma.MethodsPeripheral venous blood was collected from five patients with pituitary adenoma before SRS using Gamma Knife and at the 1 week and 1 month follow-up visits. Plasma endostatin and VEGF levels were measured using commercially available enzyme-linked immunosorbent assay kits. Peripheral blood samples were obtained from 10 healthy volunteers as controls.ResultsMean baseline plasma endostatin level (105.3 ng/mL, range, 97.0-120.2 ng/mL) in patients with pituitary adenoma was higher than that of the healthy controls (86.6 ng/mL, range, 71.3-98.2 ng/mL) (p=0.001). Mean plasma VEGF level was 89.5 pg/mL (range, 24.1-171.8 pg/mL) in patients with pituitary adenoma at baseline and 29.3 pg/mL (range, 9.2-64.3 pg/mL) in the control group (p=0.050). Plasma endostatin level changed to 106.6 ng/mL 1 week after SRS and decreased to 95.9 ng/mL after 1 month. Plasma VEGF level following SRS decreased to 74.1 pg/mL after 1 week and 79.0 pg/mL after 1 month. There was a trend toward decreased plasma endostatin and VEGF concentrations 1 month after SRS compared to baseline levels (p=0.195, p=0.812, respectively).ConclusionPlasma endostatin and VEGF levels in patients with pituitary adenoma were significantly elevated over controls at baseline, which decreased from baseline to 1 month after SRS for pituitary adenomas.

Cyberknife® Stereotactic Radiosurgery for Pituitary Adenomas: Clinical Outcomes

AMAC: Kalinti ve/veya nuks hipofiz adenomlarinin tedavisinde stereotaktik radyocerrahi alternatif bir tedavi secenegidir. Bu yazida klinigimizde Cyberknife® stereotaktik radyocerrahi (SRC) uyguladigimiz hipofiz adenomlu hastalarin tedaviye yanitlarinin degerlendirilmesi amaclanmistir.YONTEMLER: Ankara Onkoloji Hastanesi Radyasyon Onkolojisi Kliniginde, Ocak 2010- Haziran 2013 tarihleri arasinda besi fonksiyonel ve ikisi non-fonksiyonel olmak uzere toplamda yedi hipofiz adenomlu olguya SRC uygulandi. Olgularda ortanca yas: 36 (aralik, 30-60) ve olgularin % 71'i (n=5) erkek cinsiyet idi. Hemofili hastaligi olan bir hasta disindaki tum olgulara cerrahi uygulanmis idi. Fonksiyonel adenomlu dort olgu medikal tedaviye yanitsiz idi ve yinelemis tumorlerinin olmasi nedeni ile radyocerrahi karari alindi. Iki olgu ise cerrahi sonrasi kalinti tumor nedeni ile, bir olguda cerrahi yapilamadigi icin primer olarak SRC uygulandi. Recete edilen ortanca doz, 22 Gy (aralik, 20-25 Gy), 3-5 fraksiyonda, ortanca % 84 (aralik, % 80-% 93) izodoz ile uygulandi.BULGULAR: Ortanca takip zamani: 18 ay (aralik, 14-55 ay) idi. Bir olgu (non-fonksiyonel) 55 aylik izleminde klinik ve radyolojik olarak tam yanit gosterirken, bir fonksiyonel hipofiz adenomlu olgu ise progrese oldu. Yedi olgunun 6'sinda (% 86) radyolojik olarak tumor kontrolu saglandi.SONUC: Kalinti ve/veya nuks hipofiz adenomlarinin tedavisinde stereotaktik radyocerrahi etkin ve guvenli bir tedavi secenegi olabilir.

Radiation-associated secondary brain tumors after conventional radiotherapy and radiosurgery

Although there is not enough strong molecular evidence for radiation to be a causal factor for the development of secondary brain tumors, a relationship has still been found. There is a slight but significant 2–2.7% increased risk of secondary brain tumors after conventional radiotherapy. However, this risk is small and should not preclude the use of radiotherapy as an effective treatment for uncontrolled pituitary tumors. The risk of radiosurgery-associated secondary brain tumors has not been precisely determined. Taking into account the considerable number of patients who received radiosurgery worldwide and the small number of secondary brain tumors, radiosurgery seems to be a safe treatment modality. This review summarizes the pathogenesis, prevalence and characteristics of secondary brain tumors after conventional radiotherapy and stereotactic radiosurgery for pituitary adenomas.

Hypopituitarism After Stereotactic Radiosurgery for Pituitary Adenomas

Studies of new-onset Gamma Knife stereotactic radiosurgery (SRS)-induced hypopituitarism in large cohort of pituitary adenoma patients with long-term follow-up are lacking. We investigated the outcomes of SRS for pituitary adenoma patients with regard to newly developed hypopituitarism. This was a retrospective review of patients treated with SRS at the University of Virginia between 1994 and 2006. A total of 262 patients with a pituitary adenoma treated with SRS were reviewed. Thorough endocrine assessment was performed immediately before SRS and in regular follow-ups. Assessment consisted of 24-hour urine free cortisol (patients with Cushing disease), serum adrenocorticotropic hormone, cortisol, follicle-stimulating hormone, luteinizing hormone, insulin-like growth factor-1, growth hormone, testosterone (men), prolactin, thyroid-stimulating hormone, and free T(4). Endocrine remission occurred in 144 of 199 patients with a functioning adenoma. Tumor control rate was 89%. Eighty patients experienced at least 1 axis of new-onset SRS-induced hypopituitarism. The new hypopituitarism rate was 30% based on endocrine follow-up ranging from 6 to 150 months; the actuarial rate of new pituitary hormone deficiency was 31.5% at 5 years after SRS. On univariate and multivariate analyses, variables regarding the increased risk of hypopituitarism included suprasellar extension and higher radiation dose to the tumor margin; there were no correlations among tumor volume, prior transsphenoidal adenomectomy, prior radiation therapy, and age at SRS. SRS provides an effective and safe treatment option for patients with a pituitary adenoma. Higher margin radiation dose to the adenoma and suprasellar extension were 2 independent predictors of SRS-induced hypopituitarism.

Stereotactic radiosurgery for pituitary adenomas: a comprehensive review of indications, techniques and long-term results using the Gamma Knife

This study reviews the long-term clinical results of stereotactic radiosurgery in the treatment of pituitary adenoma patients. We reviewed the outcomes of 298 patients who underwent Gamma Knife radiosurgery for recurrent or residual pituitary adenomas. These results are compared to other contemporary radiosurgical series. Pituitary tumors are well-suited for radiosurgery, since radiation can be focused on a well circumscribed region, while adjacent neural structures in the suprasellar and parasellar regions are spared. The overall rate of volume reduction following stereotactic radiosurgery is 85% for non-secretory adenomas that are followed for more than 1-year. The rates of hormonal normalization in patients with hypersecretory adenomas can vary considerably, and tends to be higher in patients with Cushing's Disease and acromegaly (remission rate of approximately 53% and 54%, respectively) when compared with patients who have prolactinomas (24% remission) and Nelson's syndrome (29%) remission. Advances in dose delivery and modulation of adenoma cells at the time of radiosurgery may further improve results. Although the effectiveness of radiosurgery varies considerably depending on the adenoma histopathology, volume, and radiation dose, most studies indicate that radiosurgery when combined with microsurgery is effective in controlling pituitary adenoma growth and hormone hypersecretion. Long-term follow-up is essential to determine the rate of endocrinopathy, visual dysfunction, hormonal recurrence, and adenoma volume control.

Fractionated radiotherapy versus stereotactic radiosurgery for pituitary adenomas

Fractionated radiotherapy versus stereotactic radiosurgery for pituitary adenomas

The role of fractionated radiotherapy and stereotactic radiosurgery for pituitary adenomas

The role of fractionated radiotherapy and stereotactic radiosurgery for pituitary adenomas

The efficacy of fractionated radiotherapy and stereotactic radiosurgery for pituitary adenomas

The objective of this retrospective cohort study was to define the efficacy and safety of fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) for the treatment of patients with pituitary adenoma. Between January 1995 and April 2006, 125 consecutive patients with pituitary adenomas (54 hormone-secreting adenomas and 71 nonsecretory adenomas) received FRT or underwent SRS. Sixty-four patients received FRT, for which the mean total dose was 50.4 grays (Gy) (range, 48-54 Gy), and 61 patients underwent gamma-knife SRS with mean marginal dose of 25.1 Gy (range, 9-30 Gy). After mean follow up of 36.7 months, the tumor volume was increased in only 4 patients (3.2%). The overall actuarial progression-free survival rate was 99% at 2 years and 97% at 4 years. No difference was observed between the FRT group and the SRS group in the control of tumor growth. Based on the endocrinologic results in the patients who had secretory adenomas, the overall hormone complete remission rate was 26.2% at 2 years and 76.3% at 4 years. The median time to complete remission was 26 months in the SRS group and 63 months in the FRT group (P = .0068). Hypopituitarism developed as a delayed complication in 11.5% of patients at a median of 84 months. Both FRT and SRS were efficient treatment modalities for the control of tumor growth in patients with pituitary adenomas. The current results indicated that single-dose radiosurgery more promptly produces an effect on the hypersecretion of pituitary hormones and may be recommended over FRT for suitable patients.

Stereotactic Radiosurgery for Pituitary Adenomas: An Intermediate Review of Its Safety, Efficacy, and Role in the Neurosurgical Treatment Armamentarium

Stereotactic Radiosurgery for Pituitary Adenomas: An Intermediate Review of Its Safety, Efficacy, and Role in the Neurosurgical Treatment Armamentarium

Stereotactic radiosurgery for pituitary adenomas: an intermediate review of its safety, efficacy, and role in the neurosurgical treatment armamentarium

Pituitary adenomas are very common neoplasms, constituting between 10 and 20% of all primary brain tumors. Historically, the treatment armamentarium for pituitary adenomas has included medical management, microsurgery, and fractionated radiotherapy. More recently, radiosurgery has emerged as a viable treatment option. The goal of this research was to define more fully the efficacy, safety, and role of radiosurgery in the treatment of pituitary adenomas. Medical literature databases were searched for articles pertaining to pituitary adenomas and stereotactic radiosurgery. Each study was examined to determine the number of patients, radiosurgical parameters (for example, maximal dose and tumor margin dose), duration of follow-up review, tumor growth control rate, complications, and rate of hormone normalization in the case of functioning adenomas. A total of 35 peer-reviewed studies involving 1621 patients were examined. Radiosurgery resulted in the control of tumor size in approximately 90% of treated patients. The reported rates of hormone normalization for functioning adenomas varied substantially. This was due in part to widespread differences in endocrinological criteria used for the postradiosurgical assessment. The risks of hypopituitarism, radiation-induced neoplasia, and cerebral vasculopathy associated with radiosurgery appeared lower than those for fractionated radiation therapy. Nevertheless, further observation will be required to understand the true probabilities. The incidence of other serious complications following radiosurgery was quite low. Although microsurgery remains the primary treatment modality in most cases, stereotactic radiosurgery offers both safe and effective treatment for recurrent or residual pituitary adenomas. In rare instances, radiosurgery may be the best initial treatment for patients with pituitary adenomas. Further refinements in the radiosurgical technique will likely lead to improved outcomes.

Stereotactic Radiosurgery for Pituitary Adenomas: A Review of the Literature

Pituitary adenomas are very common neoplasms and represent between 10 and 20% of all primary brain tumors. Historically, the treatment armamentarium for pituitary adenomas included medical management, microsurgery, and fractionated radiotherapy. More recently, radiosurgery has emerged as a viable treatment option. The goal of this research is to define accurately the efficacy, safety, and role of radiosurgery for treatment of pituitary adenomas. Medical literature databases from 1965 to 2003 were searched for articles pertaining to pituitary adenomas and stereotactic radiosurgery. Each study was evaluated for the number of patients, radiosurgical parameters (e.g. tumor margin dose), length of follow-up, tumor growth control rate, complications, and rate of hormonal normalization in the case of functioning adenomas. A total of 34 published studies including 1567 patients were reviewed. Radiosurgery offers a tumor growth control rate of approximately 90%. The reported rates of hormonal normalization for functioning adenomas vary substantially. This range is in part due to widespread differences in endocrinological criteria utilized for post-radiosurgical assessment. Thus far, the risks of radiation induced neoplasia and cerebral vasculopathy associated with radiosurgery appear to be lower than for fractionated radiation therapy. The incidence of other serious complications following radiosurgery is quite low. Although surgical resection typically is the primary treatment modality, stereotactic radiosurgery offers safe and effective treatment for recurrent or residual pituitary adenomas. In rare instances, radiosurgery may be the best initial treatment for patients with pituitary adenomas. Refinements in the radiosurgical technique will likely lead to improved outcomes.

Stereotactic radiosurgery for Cushing disease.

The most common cause of Cushing syndrome is Cushing disease, in which hypercortisolism is produced by a functional adrenocorticotropic hormone-producing adenoma of the anterior pituitary gland. The common therapies available include microsurgical resection, conventional fractionated radiotherapy, and stereotactic radiosurgery (SRS). In this article the authors review the indications, results, and complications associated with SRS in the treatment of Cushing disease. In as many as 90% of patients SRS results in disease remission, which is defined as a normal 24-hour urinary free cortisol level and a normal or subnormal morning serum cortisol level. Although in most patients who are subsequently cured a marked decrease in the serum cortisol level is demonstrated within 3 months after treatment, a biochemical cure may be delayed up to 3 years in some cases. Complications following SRS for pituitary adenomas are uncommon, particularly in patients with microadenomas, which are most commonly seen in Cushing disease. The most common complication is hypopituitarism, which occurs in up to 50% of patients with a mean latency period of 5 years. Radiation-induced optic neuropathy has been reported in less than 2% of cases and induction of a secondary neoplasm in less than 1% of cases. For patients with Cushing disease, the rate of endocrinological cure following SRS appears to be similar to that attained using microsurgical resection. In contrast to surgery, SRS has the benefit of being noninvasive and associated with a very low incidence of diabetes insipidus, although hypopituitarism may be more common with SRS. With continued follow-up patient reviews and additional experience with SRS, it may become possible to make more definitive statements regarding SRS as the initial treatment for patients with Cushing disease.

Four Years’ Experiences in the Treatment of Pituitary Adenomas with Gamma Knife Radiosurgery

To determine the tumor control rates and endocrinological responses after stereotactic radiosurgery for pituitary adenomas, we reviewed our experience in 65 patients (40 men, 25 women) treated in the Gamma Knife during the last 4 years. The mean age was 41.6 years (range 19–69 years). 43 patients had endocrinologically active tumors (20 growth hormone-secreting, 19 prolactin-secreting and 4 ACTH-secreting adenomas). 22 had nonfunctioning adenomas. 39 patients had a macroadenoma and 26 patients had a microadenoma. 33 patients underwent Gamma Knife radiosurgery for recurrent or residual tumors after microsurgery. 50 patients have had follow-up neuroimaging studies and/or hormonal evaluation. The follow-up period was 25.5 months (range 3 to 54 months). The margin of the tumor was incorporated within the 50 to 90% isodose. The mean number of isocenters was 3.8 and the mean marginal dose was 25.4 Gy (range 15 to 36 Gy). 27 out of 40 patients (65.7%) showed decreased tumor volume to less than 50% of the initial volume. In 17 out of 38 patients (44.7%) with endocrinologically active tumors, the hormonal level fell to within the normal range. Two patients had delayed complications: in one case there was pituitary insufficiency and in the other a visual disturbance. Gamma Knife radiosurgery seems to be effective adjuvant therapy for pituitary adenoma in selected cases. More long-term follow-up is required to evaluate the efficacy and side effects further.

Stereotactic radiosurgery for pituitary adenomas: imaging, visual and endocrine results.

To determine the endocrine, ophthalmologic, and tumor growth control responses after stereotactic radiosurgery using the gamma unit, we reviewed our experience in 35 patients with pituitary adenomas. Twenty-four females and 11 males (mean age 47 years, range 9-81 years) had radiosurgery with average follow-up of 26 months (range 6-60 months). Most patients were refractory to surgical removal. Fifteen patients had Cushing's disease. Prior transsphenoidal resection was performed in 14 patients (6 had two prior operations), fractionated radiotherapy in 3, and adrenalectomy in 2. In 11 evaluable patients, the hormone response was normalized in 8, decreased in 2 and increased in 1. Five patients remained on cortisol suppression. Of 12 patients with imaging follow-up, 4 had decreased tumor size, 6 had no change, and 2 had an increase; these 2 patients underwent subsequent surgery. Ten patients had acromegaly, and 6 had undergone prior surgery. Of 8 evaluable patients, growth hormone secretion has normalized in 3, decreased in 3, and increased in 2. Six tumors decreased in size, and 2 were unchanged. One patient had repeat resection 21 months after radiosurgery and one patient underwent repeat radiosurgery. Ten patients had non-secreting adenomas; all 10 had prior operations (1-4 operations, 6 underwent frontal craniotomy) and 5 had undergone fractionated radiotherapy. Eight patients had panhypopituitarism prior to radiosurgery. Four tumors decreased in size and 6 were without change.(ABSTRACT TRUNCATED AT 250 WORDS)