Incidence of cerebral infarction after radiotherapy for pituitary adenoma

Radiotherapy and Mortality in Pituitary Adenomas

BACKGROUND

Pituitary adenomas (PA), comprising 10-20% of intracranial tumors, are classified as functioning and non-functioning and are further divided by size. Non-functioning tumors cause mechanical symptoms while functioning ones result in hormonal hypersecretion syndromes. Initial treatment involves surgery, with medical treatment for prolactinomas. Radiotherapy (RT) is employed as an adjuvant treatment, with various modalities including conventional, stereotactic radiosurgery (SRS), and fractionated stereotactic RT (FSRT). Although effective, RT is associated with complications and toxicities such as hypopituitarism, optic neuritis, secondary CNS tumors, and neurocognitive deficits.

AIM

Describe the information on mortality from radiotherapy as treatment of functioning PA.

METHODS

A PubMed search spanning 2000-2017 was conducted for articles on pituitary RT.

RESULTS

Conventional RT entails high-energy radiation over multiple sessions, while SRS delivers precise high doses in a single session. FSRT offers enhanced precision using a linear accelerator, delivering multiple doses. Optic structure proximity and tumor volume dictate RT modality. Studies have shown SRS and FSRT's efficacy in tumor and endocrine control, with variable risks and complications. Mortality rates in pituitary adenomas treated with RT have been evaluated, revealing complexities. Acromegaly, associated with increased mortality due to cerebrovascular disease, may result from RT. Irradiation of non-functioning pituitary macroadenomas also elevates cerebrovascular risk, while radiotherapy-induced hypopituitarism is associated with increased cardiovascular mortality. RT-induced damage is attributed to microvascular lesions and arteriolar changes.

CONCLUSION

Modern techniques mitigate complications, and although safer, long-term studies are needed. Multidisciplinary evaluation guides the treatment decision, optimizing efficacy and minimizing risk, ultimately improving the patient's quality of life.

Risk of stroke-specific mortality after radiotherapy in patients with primary brain tumours

Introduction

Stroke is an established complication in cancer patients, amongst whom brain tumour patients have the highest risk of fatal stroke. Radiotherapy is an important treatment for brain tumours and is associated with increased risk of cerebrovascular disease. However, the impact of brain irradiation on stroke-related deaths in brain tumour patients is unknown, and the timing of any effect uncertain. This study investigates the relationship between radiotherapy and stroke-specific mortality (SSM) in patients with primary brain tumours.

Methods

Patients of any age diagnosed with histologically confirmed primary brain tumours between 1992 and 2015 were abstracted from the Surveillance, Epidemiology, and End Results (SEER) database. Primary outcome was impact of radiotherapy on 5-year SSM. Cumulative SSM rates under competing risk assumptions were estimated and stratified by intervention type. Time-dependent hazard ratios were estimated to identify when the radiotherapy impact was greatest.

Results

85,284 patients with primary brain tumour diagnoses were analysed. Overall, the 5-year cumulative SSM rate was low (0.6%) with the highest rate (0.76%) in patients receiving no treatment, in whom it mainly occurred < 1 month after diagnosis. SSM rates were lower in patients treated with radiotherapy alone (0.27%) or radiotherapy plus surgery (0.24%); stroke-related deaths also occurred later in these groups. While these patterns were observed in both glioblastoma and non-glioblastoma patients, stroke deaths tended to occur later in non-glioblastoma patients receiving radiotherapy. Relative to the 'no treatment' group, the highest risk of stroke mortality in radiotherapy treated patients occurred 3.5-4 years after diagnosis.

Conclusion

The risk of SSM is low in patients with primary brain tumours and is not increased by radiotherapy. Two different patterns were observed: acute stroke mortality in patients receiving no treatment, and delayed stroke mortality in patients receiving radiotherapy (+/- surgery) with the latter peaking 3.5-4 years after diagnosis.

Management after initial surgery of nonfunctioning pituitary adenoma: surveillance, radiotherapy or surgery?

INTRODUCTION

The first line of treatment for nonfunctioning pituitary adenoma (NFPA) is surgery. Adjuvant radiotherapy or surveillance and new treatment (second surgical operation or salvage radiotherapy) in case of recurrence are options discussed at the multidisciplinary tumor board. The purpose of this study was to evaluate the therapeutic outcome for each option.

METHODS

The records of 256 patients followed with NFPA between 2007 and 2018 were retrospectively reviewed. Mean age at initial surgery was 55 years [18-86]. Post-operative MRI found a residual tumor in 87% of patients. Mean follow-up was 12.1 years [0.8-42.7].

RESULTS

After initial surgery, 40 patients had adjuvant radiotherapy. At 5, 10 and 15 years progression-free survival (PFS) was significantly different after surgery alone (77%, 58% and 40%) compared to surgery and adjuvant radiotherapy (84%, 78% and 78%) (HR = 0.24 [0-0.53] p < 0.0005). Overall, after first, second or third surgical operation, 69 patients had adjuvant radiotherapy and 41 salvage radiotherapy. Five-year PFS was similar for adjuvant (90%) and salvage radiotherapy (97%) (p = 0.62). After a second surgical operation, 62% and 71% of patients were irradiated after 2 and 5 years respectively. The risk of corticotropic and thyrotropic deficiency rates were 38% and 59% after second or third surgical operation and 40% and 73% after radiotherapy. Brain tumors occurred in 4 patients: 1 meningioma present at initial surgery, and after radiotherapy, 1 neurinoma which appeared at 5 years, 1 glioblastoma at 13 years and 1 meningioma at 20 years.

CONCLUSION

Among patients treated by surgery for NFPA, a "wait-and-see" attitude should be an option since adjuvant radiotherapy is not superior to salvage radiotherapy. However, in case of recurrence or progression, the authors recommended delivery of salvage radiotherapy to avoid a second surgical operation.

Cerebral Infarction in Childhood-Onset Craniopharyngioma Patients: Results of KRANIOPHARYNGEOM 2007

Background

Cerebral infarction (CI) is a known vascular complication following treatment of suprasellar tumors. Risk factors for CI, incidence rate, and long-term prognosis are unknown for patients with childhood-onset craniopharyngioma (CP).

Methods

MRI of 244 CP patients, recruited between 2007 and 2019 in KRANIOPHARYNGEOM 2007, were reviewed for CI. Risk factors for CI and outcome after CI were analyzed.

Results

Twenty-eight of 244 patients (11%) presented with CI based on reference assessment of MRI. One CI occurred before initial surgery and one case of CI occurred after release of intracystic pressure by a cyst catheter. 26 of 28 CI were detected after surgical tumor resection at a median postoperative interval of one day (range: 0.5-53 days). Vascular lesions during surgical procedures were documented in 7 cases with CI. No relevant differences with regard to surgical approaches were found. In all 12 irradiated patients, CI occurred before irradiation. Multivariable analyses showed that hydrocephalus and gross-total resection at the time of primary diagnosis/surgery both were risk factors for CI. After CI, quality of life (PEDQOL) and functional capacity (FMH) were impaired.

Conclusions

CI occurs in 11% of surgically-treated CP cases. Degree of resection and increased intracranial pressure are risk factors, which should be considered in the planning of surgical procedures for prevention of CI.

STA-MCA Bypass in Carotid Stenosis after Radiosurgery for Cavernous Sinus Meningioma

BACKGROUND

Cavernous sinus meningiomas (CSM) are mostly non-surgical tumors. Stereotactic radiosurgery (SRS) or radiotherapy (SRT) allow tumor control and improvement of pre-existing cranial nerve (CN) deficits. We report the case of a patient with radiation-induced internal carotid artery (ICA) stenosis. We complete the picture with a review of the literature of vascular and non-vascular complications following the treatment of CSMs with SRS or SRT.

METHODS

After a case description, a systematic literature review is presented, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2015 guidelines.

RESULTS

115 abstracts were screened and 70 titles were retained for full-paper screening. A total of 58 articles did not meet the inclusion criteria. There were 12 articles included in our review, with a follow-up ranging from 33 to 120 months. Two cases of post-SRT ischemic stroke and one case of asymptomatic ICA stenosis were described. Non-vascular complications were reported in all articles.

CONCLUSION

SRS and SRT carry fewer complications than open surgery, with similar rates of tumor control. Our case shows the importance of a follow-up of irradiated CSMs not only by a radio-oncologist, but also by a neurosurgeon, illustrating the importance of multidisciplinary management of CSMs.

Outcomes of adolescents and young adults treated for brain and skull base tumors with pencil beam scanning proton therapy

BACKGROUND

The use of proton therapy (PT) in adolescents and young adults (AYAs) is becoming increasingly popular. This study aims to assess the outcomes and late toxicity consequences in AYAs (15-39 years) with brain/skull base tumors treated with pencil beam scanning proton therapy.

METHODS

One hundred seventy six AYAs treated curatively at the Paul Scherrer Institute (PSI) were identified. Median age was 30 years (range 15-39) and median prescribed dose was 70.0 Gy (relative biological effectiveness [RBE]) (range 50.4-76.0). The most common tumors treated were chordomas/chondrosarcomas (61.4%), followed by gliomas (15.3%), and meningiomas (14.2%).

RESULTS

After a median follow up of 66 months (range 12-236), 24 (13.6%) local only failures and one (0.6%) central nervous system (CNS) distant only failure were observed. The 6-year local control, distant progression-free survival, and overall survival were 83.2%, 97.4%, and 90.2%, respectively. The 6-year high-grade (≥grade [G] 3) PT-related late toxicity-free survival was 88.5%. Crude late toxicity rates were 26.2% G1, 37.8% G2, 12.2% G3, 0.6% G4, and 0.6% G5. The one G4 toxicity was a retinopathy and one G5 toxicity was a brainstem hemorrhage. The 6-year cumulative incidences for any late PT-related pituitary, ototoxicity, and neurotoxicity were 36.3%, 18.3%, and 25.6%; whilst high-grade (≥G3) ototoxicity and neurotoxicity were 3.4% and 2.9%, respectively. No secondary malignancies were observed. The rate of unemployment was 9.5% pre-PT, increasing to 23.8% post-PT. Sixty-two percent of survivors were working whilst 12.7% were in education post-PT.

CONCLUSIONS

PT is an effective treatment for brain/skull base tumors in the AYA population with a reasonable late toxicity profile. Despite good clinical outcomes, around one in four AYA survivors are unemployed after treatment.

Occlusive radiation cerebral vasculopathy implies medical complexity: a case report

Background

Cranial irradiation is one of the main treatment modalities for central nervous system tumors. It carries many complications, one being occlusive radiation vasculopathy of large vessels. It is an underrecognized etiology for stroke, especially in the younger population. The pathophysiological process is controversial, but there is much literature supporting the theory of its being a secondary form of moyamoya disease.

Case presentation

A 31-year-old Caucasian man with a history of pineal blastoma at the age of 3 years, which was treated with resection, radiotherapy, and chemotherapy, presented to our institution with right M1 stroke. Further assessment by computed tomographic perfusion study with acetazolamide demonstrated steal phenomenon of the right middle cerebral artery territory (type III response) with a small internal region of matched cerebral blood volume defect (that is, infarct core). Coincidentally, he was found to have multiple brain masses consistent with meningiomas. Occlusive radiation vasculopathy was the most likely culprit of the patient’s stroke. The patient was treated medically with “baby” acetylsalicylic acid and clopidogrel for 3 months, then continued only on baby acetylsalicylic acid.

Conclusion

Late-onset occlusive radiation vasculopathy is a potentially severe iatrogenic manifestation of radiotherapy that requires a high index of suspicion as an etiology of stroke in young population, especially those with coexistent meningioma that might be a strong indicator for occlusive radiation vasculopathy as the stroke culprit. We reviewed the available literature to better understand the pathogenesis, clinical presentation, and treatment options of occlusive radiation vasculopathy. Applying perfusion studies with acetazolamide measures the cerebrovascular reserve in patients with occlusive radiation vasculopathy, which could help in determining the appropriate available treatment option.

Sequelae and management of radiation vasculopathy in neurosurgical patients

The term "radiation vasculopathy" defines a heterogeneous and poorly defined complex of vessel injury due to radiation. Radiation vasculopathy remains underrecognized and poorly treated with respect to head and neck radiotherapy. Distinct injury patterns to small (≤ 100-μm), medium (> 100-μm), and large (> 500-μm) vessels can occur, resulting in carotid stenosis, intracranial stenosis, and vascular anomalies (e.g., cavernous malformations, aneurysms). Because of the lack of clinical evidence and guidelines, treatment plans involve medical management, carotid endarterectomy, and carotid artery stenting and are developed on a patient-by-patient basis. In this review, the authors discuss the current pathophysiology, imaging, clinical impact, and potential treatment strategies of radiation vasculopathy with clinical pertinence to practicing neurosurgeons and neurologists. A review of 4 patients with prior head and neck tumors in whom delayed radiation vasculopathy developed after radiotherapy demonstrates the application of various treatment options in a case-by-case manner. Earlier recognition of radiation vasculopathy disease patterns may enable earlier initiation of treatment and monitoring for complications. Standardized terminology and treatments may assist with improving clinical outcomes.

The risk/benefit ratio of radiotherapy in pituitary tumors

Radiation therapy (RT) is an effective treatment for patients with either nonfunctioning or secreting pituitary adenomas unsuccessfully treated by surgery and/or medical therapy, resulting in local control of 90-95% at 5-10 years and variable normalization of hormonal hypersecretion for patients with GH-, ACTH-, and prolactin-secreting adenomas in the range of 40-80% at 5 years; however, its use has been limited because of concerns regarding potential late toxicity of radiation and delayed efficacy in normalization of hormone hypersecretion. In the last decades, there have been advances in all aspects of radiation treatment, including more accurate immobilization, imaging, treatment planning and dose delivery. RT has evolved with the development of highly conformal stereotactic techniques and new planning and dose delivery techniques, including intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). All these new techniques allow precise and sharply focused radiation delivery reducing the dose to surrounding critical neurovascular and brain structures, and potentially limiting the long-term consequences of radiation treatments. In this review, we present a critical analysis of the more recent available literature on the use of RT in patients with both nonfunctioning and secreting pituitary adenomas, focussing particularly on the risk/benefit ratio of modern radiation techniques.

Cerebral infarction after fractionated stereotactic radiation therapy of benign anterior skull base tumors

Background

The purpose of this study was to examine the occurrence of cerebral infarction (ischemic stroke), in a large combined cohort of patients with anterior skull base meningiomas, pituitary adenomas and craniopharyngiomas, after fractionated stereotactic radiation therapy (FSRT).

Material and Methods

All patients, 18 years and older, with anterior skull base meningiomas, pituitary adenomas and craniopharyngiomas, treated with fractionated stereotactic radiation, in our center, from January 1999 to December 2015 were identified. In total 169 patients were included. The prescription dose to the tumor was 54 Gy for 164 patients (97%) and 46.0-52.2 Gy for 5 patients (3%). Cases of cerebral infarctions subsequent to FSRT were identified from the Danish National Patient Registry and verified with review of case notes. The rate of cerebral infarction after FSRT was compared to the rate in the general population with a one sample t-test after standardization for age and year. We explored if age, sex, disease type, radiation dose and dose per fraction was associated with increased risk of cerebral infarction using univariate Cox models.

Results

At a median follow-up of 9.3 years (range 0.1-16.5), 7 of the 169 patients (4.1%) developed a cerebral infarction, at a median 5.7 years (range 1.2-11.5) after FSRT. The mean cerebral infarction rate for the general population was 0.0035 and 0.0048 for the FSRT cohort (p = 0.423). Univariate cox models analysis showed that increasing age correlated significantly with the cerebral infarction risk, with a hazard ratio of 1.090 (p = 0.013).

Conclusion

Increased risk of cerebral infarction after FSRT of anterior skull base tumors was associated with age, similar to the general population. Our study revealed that FSRT did not introduce an excess risk of cerebral infarction.

Management of nonfunctioning pituitary tumors: radiotherapy

External beam radiotherapy (RT) is an essential part of the management of intracranial tumors and has been used in treating pituitary adenomas for more than five decades. It has been demonstrated that conventional RT for postoperative residual or progressive nonfunctioning pituitary adenomas (NFAs) present an excellent long-term local tumor control, although its use has been limited because of the potential late toxicity related to radiation treatments. Recent advances in radiation techniques have led to more accurate treatments, rendering obsolete many commonly held views of the "old" radiotherapy. New techniques include intensity modulated radiotherapy, volumetric-modulated arc therapy, and stereotactic techniques, either stereotactic radiosurgery or fractionated stereotactic radiotherapy. New techniques allow the delivering of higher radiation doses to the target with rapid dose fall-off in the surrounding normal tissues, and potentially limiting the long term toxicity of radiation. In this review, we present a critical analysis of the most recent available literature on the use of radiation in patients with NFAs, focusing particularly on the efficacy and safety of radiation stereotactic techniques.

Cavernous carotid stenosis following stereotactic radiosurgery for Cushing's disease: A rare complication and review of the literature

Intracranial carotid stenosis or occlusion after SRS is an extraordinarily rare event. Because of the rarity of this event, increased awareness within the neurosurgical community is required. For those with post-radiosurgical carotid stenosis who are asymptomatic, longitudinal follow up is recommended. Management depends on whether the patient is symptomatic or asymptomatic. Those who are symptomatic may require balloon angioplasty, stenting, or bypass surgery.

Ischemic stroke after radiation therapy for pituitary adenomas: a systematic review

Radiation therapy is widely used for the treatment of residual and recurrent pituitary adenomas and proved to effectively control tumor growth. However, it is suggested that this treatment might result in an increased risk of ischemic stroke. This review aims to evaluate the radiotherapy-related risk of stroke in pituitary adenoma patients. PubMed and Embase databases were systematically searched for current literature on ischemic stroke risk after radiotherapy in pituitary adenoma, in accordance with the PRISMA statement. Two authors independently selected eligible studies and extracted data. The New Castle Ottawa-scale was used for quality assessment. Out of 264 publications, 11 studies were selected, including 4394 irradiated patients. Incidence of ischemic stroke ranged from 0 to 11.6% (mean 6.7%). While one large, long term follow-up study showed a threefold increased risk of stroke after radiation therapy, another nationwide study of high quality found no significant difference in stroke risk after irradiation. Four studies, which applied stereotactic radiosurgery (SRS) or Gamma-knife surgery (GKS), found no ischemic strokes. Included studies described different radiation techniques and regimens and different lengths of follow-up. In conclusion, complications of cerebral ischemia after radiotherapy for pituitary adenoma are infrequently reported. Moreover, after correction for several confounders, no significant difference in ischemic stroke rate between irradiated and non-irradiated patients could be identified.

Mortality in adults with hypopituitarism: a systematic review and meta-analysis

PURPOSE

Hypopituitarism is a rare disorder with significant morbidity. To study the evidence on the association of premature mortality and hypopituitarism.

METHODS

A comprehensive search of multiple databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus was conducted through August, 2015. Eligible studies that evaluated patients with hypopituitarism and reported mortality estimates were selected following a predefined protocol. Reviewers, independently and in duplicate, extracted data and assessed the risk of bias.

RESULTS

We included 12 studies (published 1996-2015) that reported on 23,515 patients. Compared to the general population, hypopituitarism was associated with an overall excess mortality (weighted SMR of 1.55; 95 % CI 1.14-2.11), I ²  = 97.8 %, P = 0.000. Risk factors for increased mortality included younger age at diagnosis, female gender, diagnosis of craniopharyngioma, radiation therapy, transcranial surgery, diabetes insipidus and hypogonadism.

CONCLUSION

Hypopituitarism may be associated with premature mortality in adults. Risk is particularly higher in women and those diagnosed at a younger age.

Radiotherapy and death from cerebrovascular disease in patients with primary brain tumors

Radiotherapy is often used in the management of primary brain tumors, but late cerebrovascular risks remain incompletely characterized. We examined the relationship between radiotherapy and the risk of death from cerebrovascular disease (CVD) in this population. We used the Surveillance, Epidemiology, and End Results Program to identify 19,565 patients of any age diagnosed with a primary brain tumor between 1983-2002. Multivariable competing risks analysis and an interaction model were used to determine whether receipt of radiotherapy was associated with an increased risk of CVD-specific death, adjusting for tumor proximity to central arterial circulations of the brain. The median follow up in surviving patients was 12.75 years. Baseline characteristics were similar in patients who did and did not receive radiotherapy. Ten-year CVD-specific mortality in patients with tumors near central arterial circulations who did and did not receive radiotherapy were 0.64 % (95 % CI 0.42-0.93 %) versus 0.16 % (95 % CI 0.055-0.40 %), p = 0.01. After adjustment for demographic, tumor-related, and treatment-related covariates, patients with tumors near central arterial circulations were significantly more likely to experience CVD-specific mortality after radiotherapy (HR 2.81; 95 % CI 1.25-6.31; p = 0.01); no association was observed among patients with more distant tumors (HR 0.77; 95 % CI 0.50-1.16; p = 0.21). The interaction model showed that tumor location was a key predictor of the risk of radiotherapy-associated, CVD-specific mortality (p-interaction = 0.004). Patients receiving radiotherapy for tumors near but not distant from the central vasculature of the brain are at increased risk for death secondary to CVD, which should be considered when counseling patients.

Percutaneous transluminal angioplasty in a patient with internal carotid artery stenosis following gamma knife radiosurgery for recurrent pituitary adenoma

BACKGROUND

Intracranial vascular complications following radiosurgery are extremely rare.

CASE DESCRIPTION

We report a case of stenosis in the internal carotid artery 5 years after gamma knife radiosurgery for a recurrent pituitary adenoma. Percutaneous transluminal angioplasty was performed successfully with anatomical and functional improvement.

CONCLUSION

These results suggested the importance of monitoring for arterial stenosis in the long-term follow-up. Moreover, this is the first case of endovascular treatment as an effective therapy for intracranial arterial stenosis due to radiotherapy.

Review of cranial radiotherapy-induced vasculopathy

Cranial radiation can impact the cerebral vasculature in many ways, with a wide range of clinical manifestations. The incidence of these late effects including cerebrovascular accidents (CVAs), lacunar lesions, vascular occlusive disease including moyamoya syndrome, vascular malformations, and hemorrhage is not well known. This article reviews the preclinical findings regarding the pathophysiology of late radiation-induced vascular damage, and discusses the clinical incidence and risk factors for each type of vasculopathy. The pathophysiology is complex and dependent on the targeted blood vessels, and upregulation of pro-inflammatory and hypoxia-related genes. The risk factors for adult CVAs are similar to those for patients not exposed to cranial radiotherapy. For children, risks for late vascular complications include young age at radiotherapy, radiotherapy dose, NF1, tumor location, chemotherapy, and endocrine abnormalities. The incidence of late vascular complications of radiotherapy may be impacted by improved technology, therapeutic interventions, and appropriate follow up.

Outcomes of proton therapy for patients with functional pituitary adenomas

PURPOSE/OBJECTIVE(S)

This study evaluated the efficacy and toxicity of proton therapy for functional pituitary adenomas (FPAs).

METHODS AND MATERIALS

We analyzed 165 patients with FPAs who were treated at a single institution with proton therapy between 1992 and 2012 and had at least 6 months of follow-up. All but 3 patients underwent prior resection, and 14 received prior photon irradiation. Proton stereotactic radiosurgery was used for 92% of patients, with a median dose of 20 Gy(RBE). The remainder received fractionated stereotactic proton therapy. Time to biochemical complete response (CR, defined as ≥ 3 months of normal laboratory values with no medical treatment), local control, and adverse effects are reported.

RESULTS

With a median follow-up time of 4.3 years (range, 0.5-20.6 years) for 144 evaluable patients, the actuarial 3-year CR rate and the median time to CR were 54% and 32 months among 74 patients with Cushing disease (CD), 63% and 27 months among 8 patients with Nelson syndrome (NS), 26% and 62 months among 50 patients with acromegaly, and 22% and 60 months among 9 patients with prolactinomas, respectively. One of 3 patients with thyroid stimulating hormone-secreting tumors achieved CR. Actuarial time to CR was significantly shorter for corticotroph FPAs (CD/NS) compared with other subtypes (P=.001). At a median imaging follow-up time of 43 months, tumor control was 98% among 140 patients. The actuarial 3-year and 5-year rates of development of new hypopituitarism were 45% and 62%, and the median time to deficiency was 40 months. Larger radiosurgery target volume as a continuous variable was a significant predictor of hypopituitarism (adjusted hazard ratio 1.3, P=.004). Four patients had new-onset postradiosurgery seizures suspected to be related to generously defined target volumes. There were no radiation-induced tumors.

CONCLUSIONS

Proton irradiation is an effective treatment for FPAs, and hypopituitarism remains the primary adverse effect.

Radiation therapy in neurologic disease

Radiotherapy is a primary mode of treatment of many of the disease entities seen by the neurologist. Therefore knowledge of how ionizing radiation works and when it is indicated is a crucial part of the field of Neurology. The neurologist may also be confronted with some of the side effects and complications or radiotherapy treatment. This chapter attempts to serve as a review of the current day process of radiotherapy, a brief review of biology and physics of radiation, and how it is used in the treatment diseases which are common to the Neurologist. In addition we review the more commonly seen side effects and complications of treatment which may be seen by the neurologist.

Sauver J, Pollock BE, Garces YI, Stafford SL, Link MJ, Erickson D, Foote RL, Laack NN. The incidence of cerebrovascular accidents and second brain tumors in patients with pituitary adenoma: a population-based study

BACKGROUND

To assess the risk of cerebrovascular accidents (CVAs) and second brain tumors (SBTs) in patients with pituitary adenoma after surgery or radiotherapy.

METHODS

A cohort of 143 people from Olmsted County, who were diagnosed with pituitary adenoma between 1933 and 2000, was studied. Only patients from Olmsted County were included because of the unique nature of medical care in Olmsted County, which allows the ascertainment of virtually all cases of pituitary adenoma for this community's residents and comparisons to the general population in the county. Surgical resection was performed in 76 patients, 29 patients underwent radiotherapy (with 21 undergoing both surgery and radiotherapy), 5 patients were reirradiated, and 59 patients were managed conservatively and observed.

RESULTS

Median follow-up was 15.5 years. There was no difference in CVA-free survival between treatment groups. On univariate analysis age > 60 years (hazard ratio [HR], 11.93; 95% CI, 6.26-23.03; P < .001); male sex (HR, 3.67; 95% CI, 2.03-6.84; P < .001), and reirradiation (HR, 3.41; 95% CI, 1.05-9.68; P = .04) were associated with worse CVA-free survival. In multivariate analysis, only age > 60 years was associated with worse CVA-free survival. Compared with the general population, there was a 4-fold increase in the rate of CVAs in pituitary adenoma patients (HR, 4.2; 95% CI, 2.8-6.1). Two patients developed SBT (an irradiated patient and a surgically managed patient).

CONCLUSION

CVA is a significant risk for patients with pituitary tumors, but treatment does not seem to impact the risk. Even with long-term follow-up, SBTs are a rare event regardless of treatment modality.

Baseline characteristics and effects of ten years of growth hormone (GH) replacement therapy in adults previously treated with pituitary irradiation

CONTEXT

Little is known of the importance of previous irradiation therapy for baseline characteristics and responsiveness to GH replacement in GH deficient (GHD) adults.

OBJECTIVE/DESIGN/PATIENTS

In this prospective, single-centre, open-label study, the effects of 10-year GH replacement were determined in 18 GHD adults that had previously received conventional external fractionated pituitary irradiation therapy (IRR group) and 18 non-irradiated GHD patients (non-IRR group). All patients had adult onset disease and complete deficiency of anterior pituitary hormones and both groups were comparable in terms of age, gender, body mass index (BMI), and waist:hip ratio.

RESULTS

At baseline, IRR patients had higher serum triglyceride (TG) and insulin levels and lower high density lipoprotein (HDL)-cholesterol (HDL-C) level than non-IRR patients (all p<0.05). The 10-year GH replacement improved body composition, bone mass and serum lipid profile without any between-group differences, except for a marginally more beneficial response in serum TG level in the IRR patients. After 10 years, there was no between-group difference in any variable after correction for a higher replacement dose of glucocorticoids in the IRR patients at study end using an analysis of covariance. During the 10-year GH replacement, 5 IRR patients suffered from vascular events (2 fatal) whereas only one non-fatal vascular event occurred in the non-IRR patients.

CONCLUSIONS

IRR patients with GHD display a more severely impaired cardiovascular risk profile at baseline, which was reversed by the 10-year GH replacement after correction for the higher glucocorticoid dose at study end. However, vascular events occurred more frequently in the IRR patients.

Incidence, causative mechanisms, and anatomic localization of stroke in pituitary adenoma patients treated with postoperative radiation therapy versus surgery alone

PURPOSE

To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone.

METHODS AND MATERIALS

A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log-rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population.

RESULTS

Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049).

CONCLUSIONS

In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk factor was pre-existent coronary or peripheral artery disease.

Fractionated stereotactic radiosurgery using the Novalis system for the management of pituitary adenomas close to the optic apparatus

Radiosurgery has been proven to be an effective treatment for residual or recurrent pituitary adenomas after surgery. However, it causes severe complications when the optic apparatus is irradiated over the tolerance dose. In this study, we analyzed the feasibility of fractionated stereotactic radiosurgery to treat pituitary tumors close to the optic apparatus. Thirty-four patients from June 2006 to June 2011 with recurrent or residual pituitary adenomas close to (<3 mm) the optic apparatus were treated with fractionated stereotactic radiosurgery. Three fractions with a total dose of 2100 cGy were applied to the tumors. Imaging, examination of vision, and estimation of hormone level were regularly performed before and after radiosurgery. The mean tumor volume before fractioned stereotactic radiosurgery was 5.06±3.08 cm3 (range: 0.82-12.69 cm3). After a mean follow up of 36.8±15.7 months (range: 16-72 months), tumor size was reduced in seven (20.6%) patients and remained the same in the other 27 (79.4%) patients. Vision was improved in one patient and remained stable in the rest. Only one patient developed transient post-treatment diplopia. This study suggests that fractionated stereotactic radiosurgery is safe for treating pituitary adenomas close to the optic apparatus. Studies with more patients and longer follow-up are required to draw definite conclusions.

Updates in growth hormone treatment and mortality

PURPOSE OF REVIEW

To review the literature with regard to mortality in patients with hypopituitarism with a focus on the role of growth hormone (GH) deficiency and therapy.

RECENT FINDINGS

Mortality is increased in hypopituitarism, particularly in female patients. In recent years mortality rates appear to be trending downwards towards that of the general population. Recent studies from retrospective or postmarketing surveillance studies have suggested that patients who receive GH therapy may not have increased mortality. Recent studies regarding mortality in paediatric patients treated with GH are conflicting and this area needs further study.

SUMMARY

There are several important limitations of available data regarding mortality in hypopituitarism and even more so in the impact of GH therapy, which need to be taken into account when interpreting the available data. The data regarding mortality in patients treated with GH as children is an area of much debate and will need further studies to clarify, given the conflicting reports in recent studies.

Epidemiology, mortality rate and survival in a homogeneous population of hypopituitary patients

INTRODUCTION

Hypopituitarism is associated with higher prevalence of cardiovascular risk factors and premature death. Furthermore, some clinical and therapeutic features of hypopituitarism have been associated with a worse prognosis.

OBJECTIVE

We reviewed, retrospectively, a large series of adult patients with hypopituitarism using stringent epidemiological criteria. Prevalence, association with cardiovascular risk factors, mortality and survival have been analysed.

DESIGN AND METHODS

Two hundred and nine adult hypopituitary patients (56·9% females) from a population of 405 218 inhabitants, followed for 10 years.

RESULTS

Prevalence of hypopituitarism at the end of the study was 37·5 cases/100 000 inhabitants. Incidence of hypopituitarism was 2·07 cases/100 000 inhabitants and year. Thirty-two patients died during the period of the study. Standardized mortality rate (SMR) was 8·05, higher in males (8·92 vs 7·34) and in younger patients (84·93 vs 5·26). Diagnosis of acromegaly (P = 0·033), previous radiotherapy (P = 0·02), higher BMI (P = 0·04), diabetes mellitus (P = 0·03) and cancer (P < 0·0001) were associated with mortality. A lower survival was associated with older age at diagnosis, nontumoural causes, previous radiotherapy, diabetes mellitus with poor metabolic control and malignant disease.

CONCLUSIONS

Prevalence of hypopituitarism was 37·5 cases/100 000 inhabitants, and annual incidence was 2·07 cases/100 000 inhabitants. SMR was 8 times higher in hypopituitarism than in general population and was also higher in males and younger patients. Reduced survival was significantly related to cancer, nontumoural causes of hypopituitarism, older age at diagnosis, previous radiotherapy and diabetes mellitus with poor metabolic control.

Does pituitary radiotherapy increase the risk of stroke and, if so, what preventative actions should be taken?

Radiotherapy for pituitary adenomas is a well-established and effective treatment, but it has been linked to a number of complications, including an increased risk of cerebrovascular disease and mortality. Possible underlying mechanisms include the direct effects of radiation on cerebral vasculature and deficiencies in specific pituitary hormones. Higher administered dose of radiotherapy is one of the main predictors of stroke. Although treatment strategies for stroke prevention in patients treated with pituitary radiotherapy have not been studied, using the lowest effective radiation dose and ensuring hormone deficiencies are adequately treated may be beneficial in reducing the risk of stroke.

Ischemic stroke and transient ischemic attack after head and neck radiotherapy: a review

BACKGROUND AND PURPOSE

Cerebrovascular disease can complicate head and neck radiotherapy and result in transient ischemic attack and ischemic stroke. Although the incidence of radiation vasculopathy is predicted to rise with improvements in median cancer survival, the pathogenesis, natural history, and management of the disease are ill defined.

METHODS

We examined studies on the epidemiology, imaging, pathogenesis, and management of medium- and large-artery intra- and extra-cranial disease after head and neck radiotherapy. Controlled prospective trials and larger retrospective trials from the last 30 years were prioritized.

RESULTS

The relative risk of transient ischemic attack or ischemic stroke is at least doubled by head and neck radiotherapy. Chronic radiation vasculopathy affecting medium and large intra- and extra-cranial arteries is characterized by increasing rates of hemodynamically significant stenosis with time from radiotherapy. Disease expression is the likely consequence of the combined radiation insult to the intima-media (accelerating atherosclerosis) and to the adventitia (injuring the vasa vasorum). Optimal medical treatment is not established. Carotid endarterectomy is confounded by the need to operate across scarred tissue planes, whereas carotid stenting procedures have resulted in high restenosis rates.

CONCLUSIONS

Head and neck radiotherapy significantly increases the risk of transient ischemic attack and ischemic stroke. Evidence-based guidelines for the management of asymptomatic and symptomatic (medium- and large-artery) radiation vasculopathy are lacking. Long-term prospective studies remain a priority, as the incidence of the problem is anticipated to rise with improvements in postradiotherapy patient survival.

Future directions for surgery of the pituitary region

Pituitary surgery has evolved tremendously over the past century amidst a rapidly changing landscape of medical and radiosurgical therapies. One of the principal driving forces behind this transformation has been the benefit of minimal invasiveness, which is likely to further advance the specialty as higher-definition and more miniature optic systems and cameras, the use of robotics, and enhanced neuroimaging and neuronavigation, are further translated into the operating room. The emergence of nanotechnology will likely allow tumor-specific molecular ligands and nanoparticles to identify and differentiate tumors, and may permit manipulation of neural structures on the micron level with tools currently being developed, including the nanoknife, nanotweezers and femtosecond laser. Further advances in stereotactic radiosurgery may increase the prominence and safety associated with this technique for the treatment of pituitary pathology.

Intracranial metastatic disease rarely involves the pituitary: retrospective analysis of 935 metastases in 155 patients and review of the literature

We present a case report of a patient recently treated at our institution for an isolated non-small cell lung cancer metastatic lesion to the sella, report the lack of involvement of the pituitary gland in a large single-institution series of treated intracranial parenchymal metastases, and review the pertinent literature. We reviewed cranial imaging studies (CT and MRI) for 935 metastases in 155 patients treated at our institution over the previous 3 years for intracranial metastatic disease. Special attention was paid to the skull base to document the presence of any metastatic disease involving the pituitary gland, infundibular stalk, sella turcica (including anterior and posterior clinoids), or diaphragm sellae. We found no other involvement of the pituitary gland or other sellar structures by metastatic disease in this series. Intracranial metastatic disease rarely involves the pituitary gland and infundibular stalk parenchyma, suggesting that this structure may be safely omitted from the treatment field during WBRT and prophylactic cranial irradiation (PCI). This treatment approach should reduce the late sequelae of treatment to this critical organ.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

Fractionated stereotactic radiotherapy in the treatment of pituitary macroadenomas

Background

The use of fractionated stereotactic radiotherapy (fsrt) has evolved with technical advances in noninvasive immobilization, radiation delivery, and image guidance. The application of fsrt to pituitary tumours is aimed at reducing toxicity through improved dose conformality and reduced treatment margins. The aim of the present paper is to report our own experience and to review the published data on fsrt for pituitary macroadenomas.

Methods

Between September 2000 and October 2005, 13 patients with pituitary macroadenoma underwent fsrt at our institution. In 12 patients, radiotherapy treatment followed surgical resection (transsphenoidal resection in 8, frontal craniotomy in 3, and multiple transsphenoidal resections followed by craniotomy in 1). In 4 patients, the tumours were functional (2 adrenocorticotropic hormone–secreting, 1 prolactinoma, and 1 growth hormone–secreting); the tumours in the remaining patients were clinically non-secretory. Before radiation, 3 patients had panhypopituitarism, and 6 patients had visual field defects. All patients were treated with fsrt using non-coplanar micro–multileaf collimation portals. A median dose of 50.4 Gy (range: 45–60 Gy) was prescribed to the 76.9%–95.2% isodose surface and delivered in 1.8-Gy fractions. The median planning target volume (gross tumour plus 3 mm) was 33.5 cm3 (range: 3.2–75 cm3).

Results

After a median follow-up of 24 months (range: 6–60 months), local control was 100%. One patient achieved clinical complete response. Treatment was well tolerated acutely for all patients. Neither radiation-induced optic neuropathy nor any radiation-related endocrine dysfunction was observed in our patients.

Conclusions

In accordance with published series, we found fsrt to be safe and effective in the management of large pituitary macroadenomas.

ACTH deficiency, higher doses of hydrocortisone replacement, and radiotherapy are independent predictors of mortality in patients with acromegaly

CONTEXT

A number of retrospective studies report that patients with acromegaly have increased morbidity and premature mortality, with standardized mortality ratios (SMR) of 1.3-3. Many patients with acromegaly develop hypopituitarism as a result of the pituitary adenoma itself or therapies such as surgery and radiotherapy. Pituitary radiotherapy and hypopituitarism have also been associated with an increased SMR.

METHODS

Using the West MIDLANDS: Acromegaly database (n = 501; 275 female), we assessed the influence of prior radiotherapy and hypopituitarism (and replacement therapy) on mortality in patients with acromegaly. Median duration of follow-up was 14.0 yr (interquartile range, 7.9-21 yr).

RESULTS

All-cause mortality was elevated [SMR, 1.7 (1.4, 2.0); P < 0.001]. On external analysis, prior radiotherapy, ACTH, and gonadotropin deficiency were associated with an elevated SMR [radiotherapy SMR, 2.1 (1.7-2.6); P = 0.006; ACTH deficiency SMR, 2.5 (1.9-3.2); P < 0.0005; and gonadotropin deficiency SMR, 2.1 (1.6-2.7); P = 0.037]. On internal analysis, the relative risk (RR) of mortality was increased in the radiotherapy [RR, 1.8 (1.2-2.8); P = 0.008] and ACTH-deficiency groups [RR, 1.7 (1.2-2.5); P = 0.004], but not in the gonadotropin- or TSH-deficiency groups. In the ACTH-deficient group, increased replacement doses of hydrocortisone greater than 25 mg/d were associated with increased mortality compared to lower doses.

CONCLUSIONS

Radiotherapy and ACTH deficiency are significantly associated with increased mortality in patients with acromegaly. In ACTH-deficient patients, a daily dose of more than 25 mg hydrocortisone is associated with increased mortality compared to lower doses. These results have important implications for the treatment of patients with acromegaly and also raise issues as to the optimum hydrocortisone treatment regimens for ACTH-deficient patients.

Current therapy and drug pipeline for the treatment of patients with acromegaly

INTRODUCTION

Acromegaly is a multisystem disease resulting from chronic exposure to supraphysiological levels of growth hormone (GH), and is associated with significant morbidity and excess mortality. The etiology is almost exclusively an underlying pituitary adenoma. Current therapeutic interventions include surgery, radiotherapy, and medical therapy.

RESULTS

Despite surgery, around 50% of patients fail to achieve the biochemical targets shown to correlate with normalization of mortality rates. Radiotherapy is efficacious in controlling tumor growth and GH secretion; still, achievement of biochemical targets may take up to a decade and a number of safety issues have been raised with this treatment modality. Medical therapy, therefore, has an important role as adjuvant therapy in patients who fail to achieve control with surgery, or while awaiting the effects of radiotherapy to be realized. Furthermore, medical therapy is increasingly being used as primary therapy. Current medical therapies include dopaminergic agonists, somatostatin analogs, and GH receptor (GHR) antagonists. Dopaminergic agonists achieve biochemical targets in up to 30% of patients, and somatostatin analogs in around 60%. The currently available GHR antagonist pegvisomant effectively controls insulin-like growth factor-I levels in over 90% of patients; however, it has no effect on the tumor itself and has considerable financial implications. Research into optimizing the somatostatin and dopaminergic systems has led to promising advances in agonist development. Moieties with selectivity for various combinations of somatostatin receptor subtype receptors have been examined, along with molecules that additionally show high affinity for the dopaminergic D2 receptor. Of the molecules studied in vitro, only pasireotide (SOM230) and BIM-23A760 are currently undergoing further development. Other innovations to improve convenience of currently available drugs are also being investigated.

CONCLUSION

Significant advances in under standing of the somatostatin and dopaminergic system have aided drug development. This may lead to new clinically available therapies enabling control of acromegaly in a larger proportion of patients, and at an earlier stage in their disease management.

Mortality following pituitary radiotherapy

External beam radiotherapy has been used in the management of pituitary adenomas for nearly a century, preventing tumor regrowth following surgery for non-functioning pituitary adenomas and suppressing functional hypersecretion in those which are hormonally active. However, it has been linked with a number of potentially significant complications including formation of secondary intracranial tumors, cognitive impairment, hypopituitarism and cerebrovascular disease, as well as increased mortality. Radiation may cause a variety of vascular injuries and hemodynamic changes to the cerebral vasculature, and several authors have reported cerebrovascular complications and an increase in cerebrovascular mortality in patients receiving radiotherapy for pituitary and other central nervous system tumors. Ten years following pituitary radiotherapy, over 50% of patients develop deficiencies in one or more anterior pituitary hormones. A number of studies have demonstrated increased mortality in patients with hypopituitarism, predominantly due to cerebrovascular and cardiovascular disease. However, no clear answer has emerged with regards to causation, and pituitary radiotherapy has only been linked directly to mortality in one of these studies. Questions remain unanswered, and the use of conventional external beam radiotherapy in the management of pituitary disease must involve a critical risk-benefit analysis in each case.

Baseline characteristics and the effects of two years of growth hormone (GH) replacement therapy in adults with GH deficiency previously treated for acromegaly

CONTEXT

The effects of GH replacement in GH-deficient (GHD) adults previously treated for acromegaly are not well known. OBJECTIVE, DESIGN, AND PATIENTS: In this single-center, open-labeled, prospective study, 10 consecutive GHD adults with cured acromegaly (A group) and 10 matched GHD adults with previous nonfunctioning hypopituitary disease (NF group) were included. Comparisons were made at baseline and in the responses in body composition, muscle strength, bone mass, and metabolic indices during 2 yr of GH replacement.

RESULTS

At baseline, upper leg local muscle endurance and serum low-density lipoprotein-cholesterol concentration were more impaired in the A group. The A group contained three patients with hypertension, one with diabetes mellitus type 2, and one with hyperlipidemia. The NF group had only one patient with hypertension. There were no significant between-group differences in the responses to the GH therapy. Body composition and serum lipid pattern improved in both groups without any deterioration of glucose homeostasis. At study end, no difference remained between the two groups in any variable. During the 2-yr treatment, one patient had a myocardial infarction and two had cerebral infarctions in the A group, whereas no vascular event occurred in the NF group.

CONCLUSIONS

GHD patients with previous acromegaly have an impaired cardiovascular risk profile and decreased local muscle endurance as compared with other GHD patients. Two-year GH replacement eliminated these differences, but vascular events occurred more frequently in the A group. Therefore, GHD patients with cured acromegaly will benefit from GH replacement, but careful monitoring of cardiovascular status is needed.

Does acromegaly enhance mortality?

The increased mortality associated with acromegaly was first demonstrated in early epidemiological studies. Since the seminal paper by Wright et al. in 1970, nearly 20 studies have analyzed mortality rates in over 5,000 patients with acromegaly. Overall standardized mortality rates are approximately two times higher than in the general population, relating to an average reduction in life expectancy of around 10 years. The excess deaths are due predominantly to cardiovascular, cerebrovascular and respiratory disease. Malignancy deaths have been high in some studies but not others; in the largest series looking at cancer mortality in acromegaly, overall cancer deaths were not increased, but colon cancer mortality was higher than expected. In 1993, Bates et al. first demonstrated that outcome was related to the latest measurable growth hormone (GH), and treatment to reduce GH levels led to improved outcomes. Other factors predicting poor outcome include the presence of hypertension and diabetes. On the basis of current evidence, a latest GH of less than 2-2.5 mug/L is a better predictor of good outcome than a normal insulin-like growth factor-1 (IGF-1), possibly due to discrepancy between GH and IGF-1 at low GH levels. There is some evidence to suggest a more stringent GH cut-off (less than 1 mug/L) may yield additional benefit but further studies are required to investigate any added risk of increased mortality from hypopituitarism. Radiotherapy has been linked specifically to cerebrovascular mortality and its use in patients with acromegaly must involve a careful risk-benefit analysis in each case.

Management of growth hormone deficiency in adults

Growth hormone (GH) deficiency in adults is a recognised clinical entity. There is still, however, an ongoing debate of the clinical need and the importance of replacing GH in adults with severe GH deficiency. This review will focus on the overall management of adults with GH deficiency and highlight published data on dose management and treatment goals for various age groups. The efficacy data on quality of life and well-being is discussed and available and growing experience on long-term effects of GH replacement in adults and safety in terms of diabetes mellitus, pituitary tumour recurrence/regrowth and malignancy risk will be reviewed.

Immediate postoperative radiotherapy in residual nonfunctioning pituitary adenoma: Beneficial effect on local control without additional negative impact on pituitary function and life expectancy

PURPOSE

To demonstrate the benefit of immediate postoperative radiotherapy in residual nonfunctioning pituitary adenoma (NFA) in perspective to the need for hormonal substitution and life expectancy.

METHODS AND MATERIALS

Retrospective cohort analysis of 122 patients, operated for NFA between 1979 and 1998. Recurrence was defined as regrowth on computed tomography or magnetic resonance imaging. The occurrence of hormonal deficiencies was defined as the starting date of hormonal substitution therapy.

RESULTS

Seventy-six patients had residual NFA after surgery and received immediate postoperative radiotherapy (Group 1); three patients developed a recurrence, resulting in a 95% local control rate at 10 years. Twenty-eight patients had residual NFA after surgery, but were followed by a wait-and-see policy (Group 2). Sixteen developed a recurrence, resulting in a local control rate of 49% at 5 years and 22% at 10 years (p < 0.001 compared with Group 1). There were no differences between Group 1 and 2 regarding the need for substitution with thyroid hormone, glucocorticoids, and sex hormones before first surgery, directly after surgery and at end of follow-up. There were no differences in hormone substitution free survival between Group 1 and Group 2 during the study period after first surgery. Life expectancy was similar in Group 1 and 2, and their median life expectancy did not differ from median life expectancy in the general population.

CONCLUSIONS

Immediate postoperative radiotherapy provides a marked improvement of local control among patients with residual NFA compared with surgery alone, without an additional deleterious effect on pituitary function and life expectancy.

Radiotoxicity after conformal radiation therapy for benign intracranial tumors

Acoustic schwannomas, skull base meningiomas, and pituitary adenomas are benign intracranial tumors frequently managed with radiotherapy. Control rates after treatment for each of these tumors are generally high, and toxicity from treatment is relatively low. Side effect profiles depend on the tumor location, the volume treated, the dose delivered, and the presence of nearby critical structures. In addition, patient-specific factors, such as hypertension and diabetes, may increase a patient's risk for complications. This article reviews radiotoxicity after conformal radiation therapy for acoustic schwannomas, skull base meningiomas, and pituitary adenomas.

Radiosurgery for nonfunctioning pituitary adenomas

OBJECTIVE

We evaluated the effectiveness of gamma knife radiosurgery in the treatment of nonfunctioning pituitary adenomas.

METHODS

Between January 1994 and December 1999, we treated 34 patients with nonfunctioning pituitary adenomas. Thirty-one of these patients were followed for more than 30 months. Their mean age was 52.9 years. All patients underwent resection before radiosurgery. In four patients, treatment was performed with staged radiosurgery. The treatment volume was 0.7 to 36.2 cm3 (median, 2.5 cm3). The treatment dose ranged from 8 to 20 Gy (median, 14.0 Gy) to the tumor margin. In 15 patients (48.4%), the tumor either compressed or was attached to the optic apparatus. The maximum dose to the optic apparatus was from 2 to 11 Gy (median, 8 Gy).

RESULTS

Patients were followed for 30 to 108 months (median, 59.8 mo). The tumor size decreased in 18 patients (58.1%), remained unchanged in 9 patients (29.0%), and increased in four patients (12.9%). The 5-year actual tumor growth control rate was 93%. Among patients with tumor growth, two cases were secondary to cyst formation. Two patients (6.5%) required adrenal and thyroid hormonal replacement during the follow-up period after radiosurgery because of radiation-induced endocrinopathy. None of the patients sustained new cranial nerve deficits, which included optic neuropathy.

CONCLUSION

In this series, radiosurgery had a high tumor growth control rate during the long-term follow-up period. Furthermore, we observed a low morbidity rate, with endocrinopathies and optic neuropathies. This low rate included even patients in whom the tumor compressed or was attached to the optic apparatus. We emphasize the necessity of long-term follow-up to evaluate late complications.

Cerebrovascular disease in patients with pituitary tumors

Several studies have shown that patients with acromegaly have increased mortality rates for cardiovascular disease and cerebrovascular disease (CVD). Similar associations have also been seen for patients with hypopituitarism or with non-functional pituitary adenomas. This review summarizes these data and discusses the relative importance of different risk factors for cardiovascular, especially CVD, mortality among patients with acromegaly or non-functional pituitary adenomas, and for those with hypopituitarism as a result of other causes.

Gamma knife surgery for glomus jugulare tumors: an intermediate report on efficacy and safety

OBJECT

Glomus jugulare tumors are rare tumors that commonly involve the middle ear, temporal bone, and lower cranial nerves. Resection, embolization, and radiation therapy have been the mainstays of treatment. Despite these therapies, tumor control can be difficult to achieve particularly without undo risk of patient morbidity or mortality. The authors examine the safety and efficacy of gamma knife surgery (GKS) for glomus jugulare tumors.

METHODS

A retrospective review was undertaken of the results obtained in eight patients who underwent GKS for recurrent, residual, or unresectable glomus jugulare tumors. The median radiosurgical dose to the tumor margin was 15 Gy (range 12-18 Gy). The median clinical follow-up period was 28 months, and the median period for radiological follow up was 32 months. All eight patients demonstrated neurological stability or improvement. No cranial nerve palsies arose or deteriorated after GKS. In the seven patients in whom radiographic follow up was obtained, the tumor size decreased in four and remained stable in three.

CONCLUSIONS

Gamma knife surgery would seem to afford effective local tumor control and preserves neurological function in patients with glomus jugulare tumors. If long-term results with GKS are equally efficacious, the role of stereotactic radiosurgery will expand.

Gamma knife surgery for glomus jugulare tumors: an intermediate report on efficacy and safety

Object. Glomus jugulare tumors are rare tumors that commonly involve the middle ear, temporal bone, and lower cranial nerves. Resection, embolization, and radiation therapy have been the mainstays of treatment. Despite these therapies, tumor control can be difficult to achieve particularly without undo risk of patient morbidity or mortality. The authors examine the safety and efficacy of gamma knife surgery (GKS) for glomus jugulare tumors.

Methods. A retrospective review was undertaken of the results obtained in eight patients who underwent GKS for recurrent, residual, or unresectable glomus jugulare tumors. The median radiosurgical dose to the tumor margin was 15 Gy (range 12–18 Gy). The median clinical follow-up period was 28 months, and the median period for radiological follow up was 32 months.

All eight patients demonstrated neurological stability or improvement. No cranial nerve palsies arose or deteriorated after GKS. In the seven patients in whom radiographic follow up was obtained, the tumor size decreased in four and remained stable in three.

Conclusions. Gamma knife surgery would seem to afford effective local tumor control and preserves neurological function in patients with glomus jugulare tumors. If long-term results with GKS are equally efficacious, the role of stereotactic radiosurgery will expand.

Treatment of Acromegaly

Mortality is increased in individuals with acromegaly unless serum growth hormone (GH) levels are below 2 microg/l and serum insulin-like growth factor (IGF)-I levels are normal following treatment. These combined criteria have been used to define remission of the disorder in this review. Transsphenoidal surgery achieves remission targets in an average of 55% of patients. For those not in remission following surgery, options include repeat surgery or use of adjuvant therapy. Fractionated external beam pituitary radiotherapy achieves 10-year remission rates of 47% but leaves patients exposed to excess GH until remission occurs. Stereotactic radiotherapy and gamma knife radiosurgery achieve remission rates of 40% over 3 years, and dopamine agonists produce remission in about 20% of patients. Somatostatin analogues induce remission in 59% of patients within the first year of treatment. The GH receptor antagonist pegvisomant leads to remission in 90% of patients, using IGF-I levels for assessment. Optimal treatment for a patient with acromegaly thus depends on the likely efficacy of treatment, cost, surgical skill, severity of side effects, tolerability, control of tumour growth, and improvement in complications related to tumour mass. A primary surgical approach, followed by medical therapy for those not in remission, remains the preferred option in most centres.

Treatments of multi-invasive giant prolactinoma

We present a 68-year-old male patient with an exceptionally aggressive tumour which invaded to the skull base, cavernous sinus, nasopharynx, sphenoid sinus, pituitary fossa, bilateral parasellar regions, premedullary cistern, and left infratemporal fossa. Headache was the only symptom. The serum prolactin level was 95,973 ng/ml. The patient was treated by right subfrontal craniotomy with removal of the tumour. Because it did not respond well to surgical treatment and the electron micrograph showed abundant secretory granules in some parts of the specimen, post-operative radiotherapy and bromocriptine therapy were instituted. After combined therapies and a long-term follow-up, only little residual pituitary tumour was seen with serum prolactin progressively dropped to 717 ng/ml with no obvious symptoms. The histological findings, the ideal treatments and the clinical course of multi-invasive giant prolactinoma will be discussed.

Radiotherapy and stereotactic radiosurgery for pituitary tumors

Based on a review of the literature and our medical center experience, we believe that transphenoidal surgery is the procedure of choice in most patients with pituitary adenomas. Conversely, SRS is a procedure of choice for those with cavernous sinus involvement. Patients with incomplete surgical excision should be considered either for a planned stereotactic treatment or for external beam radiotherapy. The same applies to patients with recurrent tumors. We favor stereotactic treatment in patients who have tumors that are less than 35 mm in diameter and at least 3 mm from the chiasm or optic nerves. Other patients should be considered for three-dimensional conformal radiotherapy. Radiotherapy provides a good treatment alternative in those patients who either refuse surgery or have contraindications to this therapy. Contemporary radiotherapy and SRS for pituitary adenomas is safe and effective treatment. This treatment should be undertaken in medical centers with appropriate expertise and instrumentation.

Radiosurgery for residual or recurrent nonfunctioning pituitary adenoma

Object. Nonfunctioning pituitary adenomas comprise approximately 30% of all pituitary tumors. The purpose of this retrospective study is to evaluate the efficacy and role of gamma knife radiosurgery (GKS) in the management of residual or recurrent nonfunctioning pituitary adenomas.

Methods. A review was conducted of the data obtained in 42 patients who underwent adjuvant GKS at the University of Pittsburgh between 1987 and 2001. Prior treatments included transsphenoidal resection, craniotomy and resection, or conventional radiotherapy. Endocrinological, ophthalmological, and radiological responses were evaluated. The duration of follow-up review varied from 6 to 102 months (mean 31.2 months). Fifteen patients were observed for more than 40 months. The mean radiation dose to the tumor margin was 16 Gy. Conformal radiosurgery planning was used to restrict the dose to the optic nerve and chiasm.

Tumor control after GKS was achieved in 100% of patients with microadenomas and 97% of patients with macroadenomas. Gamma knife radiosurgery was equally effective in controlling adenomas with cavernous sinus invasion and suprasellar extension. No patient developed a new endocrinological deficiency following GKS. One patient's tumor enlarged with an associated decline in visual function. Another patient experienced a deterioration of visual fields despite a decrease in tumor size.

Conclusions. Gamma knife radiosurgery can achieve tumor control in virtually all residual or recurrent nonfunctioning pituitary adenomas. Dose sparing facilitates tumor management even when the adenoma is close to the optic apparatus or invades the cavernous sinus.

Cerebrovascular mortality in patients with pituitary adenoma

OBJECTIVE

To assess cerebrovascular mortality in a UK cohort of patients with pituitary adenoma known to have increased incidence of cerebrovascular accidents (CVA).

METHODS

A total of 334 patients treated at the Royal Marsden Hospital (RMH) between 1962 and 1986 with surgery and postoperative radiotherapy were followed up via the NHS Central Register (NHSCR) to identify deaths and emigrations. The causes of death were assessed by NHSCR-based death certificates and coded according to the 9th revision of ICD. Follow-up was censored at age 85, on emigration or cancellation of NHSCR. Thirteen patients could not be traced. A total of 4982 person-years was accumulated in the cohort. Expected numbers of deaths were computed from the national age-, sex- and period-specific mortality rates for England and Wales.

RESULTS

In the pituitary adenoma cohort, 128 deaths were observed compared to 80.9 expected [relative risk (RR) of death 1.58 (95% CI: 1.32-1.90)]. There were 33 cerebrovascular deaths compared with 8.04 expected (RR 4.11, 95% CI 2.84-5.75). Three deaths were from subarachnoid haemorrhage compared to 0.54 expected (RR 5.51, 95% CI 1.14-16.09). There was an increased cerebrovascular mortality in women (RR 6.93, 95% CI 4.29-10.60) compared to men (RR 2.4, 95% CI 1.24-4.20; P = 0.002) and in patients having debulking surgery (RR 5.19, 95% CI 3.50-7.42) compared to biopsy/no surgery (RR 1.33, 95% CI 0.27-3.88; P = 0.02). The RR in patients with nonsecretory tumours was 3.65 (95% CI 2.26-5.58), compared with 5.23 (95% CI 2.25-10.30) in secretory tumours (P = 0.4). The effect of age at radiotherapy was not significant (P = 0.4).

CONCLUSION

Patients with pituitary adenoma treated with surgery and radiotherapy have an increased risk of cerebrovascular mortality compared to the general population, which mirrors the increased incidence of CVA. The possible risk factors include hypopituitarism, radiotherapy and extent of surgery but none are at present proven causes. The evaluation of new treatment strategies should not only assess intermediate end-points of tumour and endocrine control but should concentrate on long-term survival with particular emphasis on CVA incidence and mortality.