Radiosurgery For Pituitary Adenomas Research Articles

Undifferentiated sarcoma of the cavernous sinus after gamma knife radiosurgery for pituitary adenoma

We report a rare case of gamma knife radiation-induced undifferentiated sarcoma in the cavernous sinus. A 24-year-old woman underwent resection of a growth hormone-secreting pituitary adenoma and gamma knife radiosurgery (maximal dose 24 Gray (Gy); marginal dose 16Gy) for residual adenoma in the right cavernous sinus. Follow-up MRI showed the disappearance of the adenoma. Fifteen years later, she developed right oculomotor nerve palsy. MRI revealed a new tumor in the right cavernous sinus. Partial removal of the tumor was performed via a transsphenoidal approach. Histological diagnosis revealed undifferentiated sarcoma. The patient received three cycles of chemotherapy containing doxorubicin and ifosfamide, then carbon ion radiotherapy (65 GyE in 26 fractions). Subsequent MRI showed tumor regression for five months. To our knowledge, this is the first report of undifferentiated sarcoma following gamma knife radiosurgery for pituitary adenoma. As patients undergoing radiosurgery face the possibility of such neoplasms developing, long-term follow-up is required.

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.

Pituitary Function Following Gamma Knife Radiosurgery for Pituitary Adenomas

To investigate the relationship between dosimetric characteristics of treatment plans and the need for hormone replacement therapy after Gamma Knife radiosurgery (GKRS) for the treatment of pituitary adenomas.

Pituitary insufficiency as a side effect after radiosurgery for pituitary adenomas: the role of the hypothalamus

Object Causes of pituitary insufficiencies as a side effect of Gamma Knife surgery (GKS) following irradiation of the hypothalamopituitary axis are still under debate. In an investigation of pituitary insufficiencies after GKS, the authors' main focus is on what role can be attributed to the hypothalamus with regard to endocrinological changes in hypothalamopituitary function following GKS. Methods A total of 108 patients consecutively treated between April 1992 and July 2003 were included in this retrospective study. All patients had undergone either transsphenoidal or transcranial surgery prior to GKS. The spot dosimetry method was used to determine doses delivered to structures of the hypothalamopituitary axis. For statistical analyses, endocrine insufficiency and deterioration in pituitary function were defined as a decrease in hormonal blood levels below the normal range for 1 or more anterior pituitary lobe hormones. Additionally, an analysis of the rate of patients requiring hormone replacement therapy after GKS due to new endocrinopathies was performed. Results Complete patient records of 61 male and 47 female patients with a mean age of 51.9 years (range 9.1–81.2 years) were available for our investigation. The overall tumor control rate was 97% and the endocrinological cure rate was 61.2%. Mean treatment doses in patients with and without new endocrine insufficiencies (shown as with/without insufficiencies and followed by probability values) were as follows: 1.3/0.8 Gy to the hypothalamus (p = 0.2); 2.2/1.6 Gy to the median eminence (p = 0.1); 6.5/4.1 Gy to the pituitary stalk (p = 0.004); and 12.4/9.5 Gy to the pituitary gland (p = 0.05). The median overall duration of follow-up after GKS was 6.7 years, with 84 patients (77.7%) whose follow-up was longer than 12 months. The median follow-up time after GKS in patients who developed a new pituitary dysfunction was 79.5 months (6.6 years, SD 3.8 years), and the median follow-up time in patients with no new insufficiencies was 78.4 months (6.5 years, SD 4 years). Conclusions Gamma Knife surgery is a safe and effective treatment for patients with residual and recurrent pituitary adenomas. The rate of pituitary insufficiencies after GKS is still lower than that after conventional radiotherapy. Very low radiation doses are directed to the hypothalamus, and thus this structure does not play a major role in the development of pituitary insufficiencies after GKS. The results of this study show that patients in whom the pituitary stalk and pituitary gland receive a high mean point dose are more likely to develop pituitary insufficiencies after GKS than those who receive a lower dose.

Radiosurgery for pituitary adenomas: evaluation of its efficacy and safety

ObjectTo assess the effects of radiosurgery (RS) on the radiological and hormonal control and its toxicity in the treatment of pituitary adenomas.MethodsRetrospective 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.ResultsThe 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 ocurred 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.ConclusionsRS 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.

Factors Associated With Endocrine Deficits After Stereotactic Radiosurgery of Pituitary Adenomas

To analyze the factors associated with anterior pituitary deficits after pituitary adenoma stereotactic radiosurgery (SRS). The tumor, pituitary stalk, and pituitary gland were segmented on the dose plans of 82 patients (secreting tumors, n = 53; nonsecreting tumors, n=29) for dose-volume analysis. No patient had undergone prior radiation therapy and all patients had at least 12 months of endocrinological follow-up (median, 63 months; mean, 69 months; range, 13-134). Thirty-four patients (41%) developed new anterior pituitary deficits at a median of 32 months (range, 2-118) after SRS. The risk of developing new anterior pituitary deficits was 16% and 45% at 2 and 5 years, respectively. Multivariate analysis of the entire group showed that poor visualization of the pituitary gland (hazard ratio [HR]=2.63, 95% confidence interval [CI]=1.10-6.25, P=.03) was associated with a higher rate of new anterior pituitary deficits. Dosimetric analysis of 60 patients whose pituitary gland could be clearly identified showed that increasing mean pituitary gland radiation dose correlated with new anterior pituitary deficits (HR=1.11, 95% CI=1.02-1.20, P=.02). New anterior pituitary deficits stratified by mean pituitary gland radiation dose: <or=7.5 Gy, 0% (0/7); 7.6 to 13.2 Gy, 29% (7/24); 13.3 to 19.1 Gy, 39% (9/23); >19.1 Gy, 83% (5/6). New endocrine deficits after pituitary adenoma radiosurgery were correlated with increasing radiation dose to the pituitary gland. Methods that limit the radiation dose to the pituitary gland during SRS may increase the probability of preserving pituitary function.

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

Gamma knife radiosurgery for endocrine-inactive pituitary adenomas

The goal of nonsecreting pituitary adenoma radiosurgery is to halt tumour growth and to maintain normal performance of the hypophysis and the functionally important structures around the sella. The effectiveness of gamma knife radiosurgery was evaluated. Over a period of 10 years (1993-2003), 140 patients with nonsecreting pituitary adenoma were treated by Leksell gamma knife at our Centre. Seventy-nine of them were followed up for longer than 3 years. Their age range was 24-73 years, with a median of 54 years. Eighty-five percent of them had previous open surgery. Fifteen patients had adenoma contact with the optic tract. Fourteen patients had a normally functioning hypophysis, 48 patients had complete panhypopituitarism, while the rest retained partial functions of the normal hypophysis. Adenoma volumes ranged between 0.1 and 31.3, the median being 3.45 ccm. The marginal dose ranged between 12 and -35 Gy, with a median of 20 Gy. The follow-up ranged from 36 to 122 months, with a median of 60 months. No adenoma growth was detected; 89% of treated adenomas decreased in size, with a median volume reduction of 61%. There was no perimeter vision impairment after radiosurgery, while 4 out of 52 patients with abnormal perimeter vision reported improvement. There was no impairment of oculomotor nerve function. Impairment of hypophysis function was observed in 2 patients. Radiosurgery has a reliable antiproliferative effect on nonsecreting pituitary adenomas. It is a safe treatment with a low risk of morbidity. Short contact between a nonsecreting pituitary adenoma and the optic pathway is not an absolute contraindication for Gamma knife radiosurgery.

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.

Radiosurgery for pituitary adenomas: Evaluation of its efficay and safety

11515 Background: Pituitary adenomas account for approximately 15% of all primary brain tumors. Multimodality treatment is often necessary and options include medical management, microsurgery, radiotherapy and radiosurgery (RS). Recently, RS has gained acceptance as a complementary treatment since it has been associated with a shorter latency for its effects and lesser morbidity than that of radiotherapy. The objective of this study was to assess the effects of RS on the radiological and hormonal control and its toxicity in the treatment of pituitary adenomas. Methods: It was done a retrospective analysis of the first 26 consecutive patients with pituitary adenomas treated with RS at our institution between 1999 and 2004. RS was delivered with a multiheaded cobalt unit (Gamma Knife). The median radiation dose was 20 Gy defined to the 50% isodose line. Almost 20% of tumors were non-secretory. The remaining were prolactinomas (31%), adrenocorticotropic hormone-secreting (34%) and growth hormone-secreting tumors (15%). 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 and 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. Results: The median follow-up was 40,8 months.Tumor growth was controlled in 96% of the cases and tumor shrinkage ocurred in 8% of the cases. Hormonal control was observed in 14 of 20 (70%) and hormonal normalization in 7 of 20 (35%) patients after RS, with a median latency period of 28,2 months. The 3-year actuarial rate of hormonal control and normalization were 51% and 47,6%, respectively, and the 5-year actuarial rate were 74% and 68,6%, respectively. There were no patients with visual deficit or hypopituitarism after RS. Conclusions: 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. No significant financial relationships to disclose.

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.

Gamma Knife Radiosurgery for Pituitary Adenomas

Although surgical extirpation by transsphenoidal microsurgery is a major remedy for pituitary adenomas, adjuvant therapy also plays an important role in achieving tumor growth control and endocrine normalization in hormone-secreting tumors. Historically, the treatment options for pituitary adenomas included microsurgery, medical management, and fractionated radiotherapy, but radiosurgery has recently emerged as a practical treatment option. In this paper, we will describe the indications, radiosurgical procedure, results, histological change, and complications of gamma knife radiosurgery (GKS) for pituitary adenomas based on our experience since 1991 and a review of the literature.

Radiosurgery for pituitary adenomas

Radiosurgery for pituitary adenomas

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.

Gamma knife radiosurgery for pituitary adenoma: early results.

In recent years, gamma knife radiosurgery (GKRS) has emerged as an important treatment modality in the management of pituitary adenomas. Treatment results after performing GKRS and the complications of this procedure are reviewed. Between 1994 and 2002, a total of 78 patients with pituitary adenomas underwent a total of 84 GKRS procedures in our medical center. This patient group comprised 46 men (59%) and 32 women (41%). All patients were treated for recurrent or residual disease after surgery or radiotherapy, with 83% presenting with extensive tumor involvement. The cavernous sinus was involved in 75 patients (96%), and 22 patients (28%) had hormone-secreting adenomas. This latter subset of patients included 12 prolactinomas (15%), 6 growth-hormone secreting tumors (8%), and 4 adrenocorticotropic hormone-secreting tumors (5%). The median tumor volume was 2.3 cm(3), and the median radiation dose was 15 Gy defined to the 50% isodose line. The mean and median follow-up periods were 41 and 36 months, respectively. GKRS was tolerated well in these patients; acute toxicity was uncommon and of no clinical significance. Late toxicity was noted in three patients (4%) and consisted of VIth cranial nerve palsy. In two patients, there was spontaneous resolution of this palsy, and in one patient, it persisted for the entire 3-year duration of follow-up. Of the 15 patients who presented with cranial nerve dysfunction, 8 (53%) experienced complete recovery and 3 (20%) showed major improvement within 12 months of therapy. Tumor volume reduction was slow, with 30% of patients showing decreased tumor volume more than 3 years after undergoing GKRS. None of the 56 patients with nonfunctioning tumors showed progression in the treated volume, and 4 (18%) of the 22 hormone-secreting tumors relapsed (P = 0.008). Of the four patients with adrenocorticotropic hormone-secreting adenomas, therapy failed in two of them. All six patients with growth hormone-producing tumors responded well to therapy. Of the 12 patients with prolactinomas 10 (83%) had normalization of hormone level and 2 patients experienced increasing prolactin level. Two patients with prolactinomas had three normal pregnancies after undergoing GKRS. GKRS is a safe and effective therapy in selected patients with pituitary adenomas. None of the patients in our study experienced injury to the optic apparatus. A radiation dose higher than 15 Gy is probably needed to improve control of hormone-secreting adenomas. Longer follow-up is required for a more complete assessment of late toxicity and treatment efficacy.

Effects of gamma knife radiosurgery of pituitary adenomas on pituitary function

Object. The authors undertook a retrospective analysis of the incidence and time course of pituitary insufficiency following gamma knife radiosurgery (GKS) for pituitary adenomas. Methods. Pituitary adenomas in 92 patients were analyzed. There were 61 hormonally inactive tumors, 18 prolactinomas, and nine somatotropic and four adrenocorticotropic adenomas. The mean tumor volume was 3.8 cm3 (range 0.2–14.6 cm3). The mean prescription dose was 15 Gy. The mean prescription isodose was 50.7%. The mean follow-up time was 4.6 years (range 1.2–10 years). The following new or deteriorating insufficiencies that did not require treatment were recorded for the different pituitary axes: follicle-stimulating hormone (FSH)/luteinizing hormone (LH) 19 (20.6%), thyroid-stimulating hormone (TSH) 32 (34.8%), adenocorticotropic hormone (ACTH) 10 (10.9%), and growth hormone (GH) 26 (28.3%). For new insufficiencies or deterioration requiring replacement therapy, the figures were as follows: FSH/LH 20 (21.7%), TSH 22 (23.9%), ACTH eight (8.7%), and GH 12 (13%). Spot dosimetry was performed in 59 patients in the hypothalamic region, the pituitary gland, and pituitary stalk. The pituitary stalks in patients with deterioration of pituitary function received a statistically higher dosage of radiation, 7.7 ± 3.7 Gy compared with 5.5 ± 3 Gy (p = 0.03). Conclusions. The function of the residual normal pituitary gland is less affected following GKS of pituitary adenomas than after fractionated radiotherapy. Nonetheless, increased attention needs to be exercised to reduce the dose to the stalk and pituitary gland to minimize the incidence of these complications.

Section 4. Pituitary: Gamma knife radiosurgery for pituitary adenoma

For the treatment of pituitary adenomas, transsphenoidal surgery is established as a first choice of treatment. However, pituitary adenomas are often not curable with surgery alone, and further treatment including radiation therapy is required to control the disease. In this report, we review the literature of gamma knife radiosurgery for pituitary adenomas and discuss the efficacy of this modern technology. Radiosurgery achieved 85–100% of growth control rates with only mild and transient neurological complications in most cases. Endocrinological normalization was obtained in more than 65% of GH producing tumors. These hormonal control rates seemed to be slightly better in GH producing tumors compared to ACTH producing tumors. To normalize the excessive GH or ACTH levels, radiosurgery for functioning adenomas requires a relatively higher dose, ideally more than 35 Gy at tumor margin. However, the adjacent optic apparatus is less tolerable for irradiation, and the tumors have to be sufficiently separated from it to prevent the radiation-induced visual deficits. Therefore, the role of surgery should not be underevaluated, and even if radiosurgery alone may be able to achieve an excellent outcome in some cases, surgical resection will remain the primary treatment for pituitary adenomas. For high-risk patients or patients with residual tumors after transsphenoidal surgery, gamma knife radiosurgery can be a first choice of treatment, achieving both growth control and hormonal remission with minimum neurological complications, which is equivalent to conventional radiation therapy but with much less risk of radiation injury to the surrounding structures.