Fractionated Stereotactic Radiotherapy for Pituitary Adenomas: Single-Center Experience in 75 Consecutive Patients

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.

Fractionated Stereotactic Radiation Therapy for Pituitary Adenomas: An alternative escalating protocol of hypofractionated stereotactic radiotherapy delivering 35Gy in 5 fractions

PURPOSE

Evaluate efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) for patients treated for pituitary adenoma (PA) with an alternative HSRT escalating protocol delivering 35Gy in 5 fractions.

MATERIAL AND METHODS

From June 2007 to March 2017, 29 patients with pituitary adenoma were treated in Antoine Lacassagne Cancer Centre with an alternative HSRT protocol. Prescribed dose was 35Gy in 5 fractions of 7Gy. Radiographic responses were assessed by annual MRI. Hormone blood samples were evaluated each year after HSRT.

RESULTS

A total of 29 patients aged between 23 and 86 years (median 54 years) were included. Twelve patients received HSRT for recurrent cases and 12 received postoperative adjuvant HSRT, 5 patients did not have surgery. After a median follow-up period of 47 months local control rate was 96%. One patient presented an out-field tumor regrowth 73 months after HSRT. The majority of PA were endocrine-active (18 patients, 62%). After HSRT, 8 patients (44%) presented complete response on initial secretion, 4 patients (23%) presented partial response on initial secretion. Four patients (14%) presented grade 2 or more acute radiation toxicities. One grade 4 visual disorder was observed for one patient.

CONCLUSIONS

HSRT delivering 35Gy in 5 fractions represents a feasible treatment and shows promising results to reduce hormonal overproduction and to improve local control in PA.

Long-term Outcomes of Hypofractionated Stereotactic Radiotherapy for the Treatment of Perioptic Nonfunctioning Pituitary Adenomas

The efficacy of stereotactic radiotherapy (SRT) has been well established for postoperative residual and recurrent nonfunctioning pituitary adenomas (NFPAs). However, the risk of visual impairment due to SRT for lesions adjacent to the optic pathways remains a topic of debate. Herein, we evaluated the long-term clinical outcomes of hypofractionated stereotactic radiotherapy (HFSRT) for perioptic NFPAs. From December 2002 to November 2015, 32 patients (18 males and 14 females; median age 63 years; range, 36-83 years) with residual or recurrent NFPAs abutting or displacing the optic nerve and/or chiasm (ONC) were treated with HFSRT. The median marginal dose was 31.3 Gy (range, 17.2-39.6) in 8 fractions (range, 6-15). Magnetic resonance imaging (MRI) and visual and hormonal examinations were performed before and after HFSRT. The median follow-up period was 99.5 months (range, 9-191). According to MRI findings at the last follow-up, the tumor size had decreased in 28 (88%) of 32 patients, was unchanged in 3 (9%), and had increased in 1 (3%). The successful tumor size control rate was 97%. Visual functions remained unchanged in 19 (60%) out of 32 patients, improved in 11 (34%), and deteriorated in 2 (6%). Two patients had deteriorated visual functions; no complications occurred because of the HFSRT. One patient developed hypopituitarism that required hormone replacement therapy. The result of this long-term follow-up study suggests that HFSRT is safe and effective for the treatment of NFPAs occurring adjacent to the ONC.

Gamma Knife radiosurgery as the initial treatment for elderly patients with nonfunctioning pituitary adenomas

PURPOSE

The aim of this study was to investigate the efficacy and safety of initial Gamma Knife radiosurgery (GKRS) for elderly patients with nonfunctioning pituitary adenomas (NFPAs).

METHODS

We retrospectively reviewed 45 elderly patients underwent GKRS as the initial treatment for NFPAs at our institution between December 2007 and December 2017. Patients' radiographic and clinical data were collected.

RESULTS

The median age of patients at the time of GKRS was 71 years (range 65-82 years). The median tumor volume was 2.6 cm³ (range 0.3-21.8 cm³). The median marginal dose was 13 Gy (range 6-23 Gy). The median maximum dose to the optic apparatus was 6.5 Gy (range 2.3-10.3 Gy). Thirty-five patients (77.8%) achieved tumor regression, 6 patients (13.3%) had tumor stable and 4 patients (8.9%) occurred tumor progression during a median radiological follow-up time of 51.4 months (range 11.1-158.7 months). The crude tumor control rate was 91.1%. The actuarial tumor control rates were 100%, 95.0%, 87.6%, and 87.6%, at 1, 3, 5, and 10 years after initial GKRS, respectively. New-onset hypopituitarism occurred in 6 patients. Two patients with pre-GKRS visual dysfunction developed further deterioration of visual function. No other radiation-induced complications were noted.

CONCLUSION

Initial GKRS can provide a high tumor control rate as well as low risk of postradiosurgical complications for elderly patients with NFPAs. Attention should be paid to avoid radiation-related adverse effects including hypopituitarism, optic neuropathy and cranial neuropathy in elderly patients.

Intensity-modulated Radiotherapy for Pituitary Somatotroph Adenomas

OBJECTIVE

To summarize our experience in the treatment of pituitary somatotroph adenomas by fractionated intensity-modulated radiotherapy (IMRT), describe the treatment outcomes, and determine predictors.

METHODS AND MATERIALS

Patients with pituitary somatotroph adenoma treated by IMRT in our institution from August 2009 to January 2019 were reviewed. A total of 113 patients (37 male) were included in this study. The median age was 33 years (range 12-67 years). A total of 112 patients had not achieved complete remission after surgery, and 1 patient was treated by radiotherapy (RT) alone because she refused to surgery. The median growth hormone level was 8.6 ng/mL (range 2-186 ng/mL) and the median insulin-like growth factor (IGF)-1 level was 732 ng/mL (range 314-1485 ng/mL) pre-RT. The radiation doses to clinical target volume were usually 50-56 Gy in 25 to 30 fractions and to gross tumor volume were 60.2 Gy in 28 fractions while simultaneous integrated boost-IMRT used. After RT, the patients were followed up with endocrine testing every 6 to 12 months and magnetic resonance imaging annually. Endocrine complete remission was defined as a normal sex- and age-adjusted IGF-1 level without any pituitary suppressive medications. The outcomes including endocrine remission and new hypopituitarism after RT were recorded. The median follow-up time was 36 months (range 6-105.5 months).

RESULTS

The endocrine complete remission rates of IGF-1 at 1, 2, 3, and 5 years were 6%, 22.8%, 48.6%, and 74.3%, respectively. The median time to complete remission was 36.2 ± 3.8 months. The tumor control rate was 99% during the follow-up. The overall incidence of RT-induced hypopituitarism was 28.3% at the last follow-up. Univariate and multivariate analysis demonstrated that tumor sizes before RT, pre-RT IGF-1 level, and age significant predicted the endocrine remission.

CONCLUSIONS

IMRT is a highly effective treatment for pituitary somatotroph adenoma. Endocrine remission rate, tumor control rate, the median time to remission and hypopituitarism incidence are similar to stereotactic radiosurgery. Age and IGF-1 level before RT were significant predictive factors in endocrine remission.

Management of patients with persistent or recurrent Cushing's disease after initial pituitary surgery

INTRODUCTION

Treatment options for persistent and recurrent Cushing's disease (CD) include an individualized approach for repeat surgery, medical treatment, radiation therapy (RT), and bilateral adrenalectomy (BLA).

AREAS COVERED

In this expert opinion perspective, the authors review the latest treatment(s) for persistent/recurrent CD. A PubMed search was undertaken (English articles through May 2020) and relevant articles discussed. Repeat pituitary surgery should be considered in most patients with proven hypercortisolism; there is potential for cure with low risk of major complications. Medical therapy is valuable either alone, while awaiting the effects of RT, or in preparation for BLA. Medical therapy includes steroidogenesis inhibitors, agents that act at the pituitary or glucocorticoid receptor level, and novel agents in development. Radiation therapy has been used successfully to treat CD, but hypopituitarism risk and delayed efficacy (improved with radiosurgery) are major drawbacks. Laparoscopic BLA is safe and effective in patients with severe, difficult-to-manage hypercortisolism, but long-term follow-up is required as corticotroph tumor progression can develop.

EXPERT OPINION

Treatment of persistent/recurrent CD is challenging. Most patients require >1 therapy to achieve long-lasting remission. There is currently no ideal single treatment option that provides high and rapid efficacy, low adverse effects, and preserves normal pituitary-adrenal axis function.

Proposed Neuroimmune Roles of Dimethyl Fumarate, Bupropion, S-Adenosylmethionine, and Vitamin D3 in Affording a Chronically Ill Patient Sustained Relief from Inflammation and Major Depression

We had discussed earlier that, after most of the primary author's multiple sclerosis (MS) symptoms were lessened by prior neuroimmune therapies, use of dimethyl fumarate (DMF) gradually subdued his asthma and urticaria symptoms, as well as his MS-related intercostal cramping; and bupropion supplemented with S-adenosylmethionine (SAMe) and vitamin D3 (vit-D3) helped remit major depression (MD). Furthermore, the same cocktail (bupropion plus supplements), along with previously discussed routines (yoga, meditation, physical exercises, and timely use of medications for other illnesses), continued to subdue MD during new difficulties with craniopharyngioma, which caused bitemporal vision loss; sphenoid sinus infections, which caused cranial nerve-VI (CN6) palsy and diplopia; and through their treatments. Impressed by the benefit the four compounds provided, in this manuscript, we focus on explaining current neuroimmune literature proposals on how: (1) DMF impedes inflammation, oxidative stress, and cell death in CNS and peripheral tissues; (2) Bupropion curbs anxiety, MD, and enhances alertness, libido, and moods; (3) SAMe silences oxidative stress and depression by multiple mechanisms; and (4) Vit-D3 helps brain development and functioning and subdues inflammation. we realize that herein we have reviewed proposed mechanisms of remedies we discovered by literature searches and physician assisted auto-experimentation; and our methods might not work with other patients. We present our experiences so readers are heartened to reflect upon their own observations in peer-reviewed forums and make available a wide body of information for the chronically ill and their physicians to benefit from.

Postsurgical Salvage Radiosurgery for Nonfunctioning Pituitary Adenomas Touching/Compressing the Optic Chiasm: Median 13-Year Postirradiation Imaging Follow-up Results

BACKGROUND

There is little information on long-term outcomes after salvage treatment by either surgery or stereotactic radiosurgery (SRS) for patients with recurrent/residual nonfunctioning pituitary adenomas (NFPAs).

OBJECTIVE

To reappraise the efficacy and safety of SRS for patients with NFPAs touching/compressing the optic apparatus (OA).

METHODS

We studied 27 patients (14 females, 13 males; mean age: 61 [range, 19-85] yr) who underwent SRS between 1998 and 2008 for NFPAs with such condition. The median tumor volume was 4.9 (range, 1.8-50.8) cc. To avoid excess irradiation to the OA, the lower part of the tumor was covered with a 50% or a 60% isodose gradient, ie 49% to 98% (mean, 84%; median, 88%) of the entire tumor received the selected doses. Median doses at the tumor periphery/OA were 7.6/11.0 (interquartile range [IQR], 5.8-9.1/10.1-11.8) Gy.

RESULTS

Seven patients (26%) were confirmed to be deceased due to unrelated diseases at a median post-SRS period of 149 (IQR, 83-158) mo. Follow-up magnetic resonance imaging (MRI) showed tumor growth in 2 patients (7%) at the 11th and 134th post-SRS month; the former underwent surgery and the other SRS. Excluding these 2 patients, the latest follow-up MRI examinations, performed 13 to 238 (median: 168, IQR: 120-180) mo after SRS, showed no size changes in 5 (19%) and shrinkage in 20 (74%) patients. Cumulative incidences of tumor growth control were 96.3% and 91.8% at the 120th and 180th post-SRS month. None of our patients developed subjective symptoms suggesting SRS-induced optic neuropathy or endocrinological impairment.

CONCLUSION

In patients with NFPAs touching/compressing the OA, SRS achieves good long-term results.

Benign Intracranial Lesions - Radiotherapy: An Overview of Treatment Options, Indications and Therapeutic Results

BACKGROUND

Radiation Therapy (RT) is an established treatment option for benign intracranial lesions. The aim of this study is to display an update on the role of RT concerning the most frequent benign brain lesions and tumors.

METHODS

Published articles about RT and meningiomas, Vestibular Schwannomas (VSs), Pituitary Adenomas (PAs), Arteriovenous Malformations (AVMs) and craniopharyngiomas were reviewed and extracted data were used.

RESULTS

In meningiomas RT is applied as an adjuvant therapy, in case of patientrefusing surgery or in unresectable tumors. The available techniques are External Beam RT (EBRT) and stereotactic ones such as Stereotactic Radiosurgery (SRS), Fractionated Stereotactic RT (FSRT), Intensity Modulated RT (IMRT) and proton-beam therapy. The same indications are considered in PAs, in which SRS and FSRT achieve excellent tumor control rate (92-100%), acceptable hormone remission rates (>50%) and decreased Adverse Radiation Effects (AREs). Upon tumor growth or neurological deterioration, RT emerges as alone or adjuvant treatment against VSs, with SRS, FSRT, EBRT or protonbeam therapy presenting excellent tumor control growth (>90%), facial nerve (84-100%), trigeminal nerve (74-99%) and hearing (>50%) preservation. SRS poses an effective treatment modality of certain AVMs, demonstrating a 3-year obliteration rate of 80%. Lastly, a combination of microsurgery and RT presents equal local control and 5-year survival rate (>90%) but improved toxicity profile compared to total resection in case of craniopharyngiomas.

CONCLUSION

RT comprises an effective treatment modality of benign brain and intracranial lesions. By minimizing its AREs with optimal use, RT projects as a potent tool against such diseases.

Post-Craniopharyngioma and Cranial Nerve-VI Palsy Update on a MS Patient with Major Depression and Concurrent Neuroimmune Conditions

We report the case of a male multiple sclerosis (MS) patient with type 2 diabetes (T2D), asthma, major depression (MD or major depressive disorder, MDD), and other chronic conditions, after his recent difficulties with craniopharyngioma and cranial nerve-VI (CN6) palsy. In addition, we show magnetic resonance image and spectroscopy (MRI, MRS), Humphrey's Visual Field (HVF), and retinal nerve fiber layer thickness (RNFLT) findings to explain the changes in the patient's health, and discuss the methods that helped/help him sustain productivity and euthymia despite long-standing problems and new CNS changes.

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.

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.

Remitting long-standing major depression in a multiple sclerosis patient with several concurrent conditions

In this report, we discuss the case of an multiple sclerosis (MS) patient, age 62, who learned to attain and sustain euthymia despite his ailments. He has Ehlers Danlos Syndrome (EDS), asthma, MS, urticaria, and major depression (MD). Despite thriving limitations, the patient is an accomplished scientist, who struggled for > twelve years to emerge from being confined to bed and wheel chair with MS, to walking with crutches, scuba diving, writing manuscripts, and living a positive life. Through former educators, he reacquired problem-solving habits to study the literature on his illnesses; keep records; try new therapies; and use pharmaceutical, nutritional, physical, and psychological methods to attain euthymia. With this inculcation, years later, he discovered that dimethyl fumarate (DMF) suppressed inflammation, cramping, urticaria, and asthma; and the combination of bupropion, S-adenosylmethionine (SAMe), vitamin-D3 (vit-D3), yoga, and self-hypnosis relieved MD. Then, after a 14-month respite, the patient, discovered that he had adult onset craniopharyngioma: a benign, recurring, epithelial tumor that grows from vestigial embryonic tissue (Rathke's pouch) which formed the anterior pituitary. The tumor grows aggressively and causes surrounding tissue and function losses. It caused headaches, disorientation, bitemporal vision loss, among other problems. To emerge from this conundrum, the patient employed his relearned habits; the above antidepressant cocktail (bupropion, SAMe, and vit-D3); and with 30 fractionated stereotactic radiation treatments shrank his tumor and gained relief. This is a single case, and methods we discovered serendipitously may not work for other chronically ill patients. Consequently, we want to encourage such patients and their physicians to discuss their experiences in peer-reviewed domains so readers may acquire new perspectives that help individualize their care, and have productive contented lives.

Radiosurgical decompression for benign perioptic tumors causing compressive cranial neuropathies: a feasible alternative to microsurgery?

Several studies have reported the efficacy and safety of hypofractionated stereotactic radiosurgery (hSRS) in the treatment of benign perioptic tumors. This study went further and evaluated the feasibility of hSRS in the treatment of those causing compressive cranial neuropathies (CCNs) among perioptic tumors with special consideration of functional improvement. Twenty-six patients with CCNs (CN II = 19; CN III/IV/VI = 9; CN V = 3) caused by perioptic tumors underwent hSRS between 2011 and 2015. hSRS was delivered in five fractions with a median marginal dose of 27.8 Gy (≈14 Gy in a single fraction, assuming an α/β of three) to a tumor volume of 8.2 ± 8.3 cm³. All tumors except one shrank after treatment, with a mean volume decrease of 35 % (range 4-84 %) during the mean follow-up period of 20 months. In 19 patients (38 eyes) with compressive optic neuropathy, vision improved in 55.3 % of eyes (n = 21), was unchanged in 36.8 % (n = 14), and worsened in 7.9 % (n = 3) (2.6 % after excluding two eyes deteriorated due to transient tumor swelling). A higher conformity index (p = 0.034) and volume of the optic apparatus receiving >23.0 Gy (p = 0.019) were associated with greater tumor shrinkage. A greater decrease in tumor volume (p = 0.035) was associated with a better improvement in vision. Ophthalmoplegia and facial hypesthesia improved in six of nine (66.7 %) and three of three (100 %) patients, respectively. There was no newly developed neurological deficit. Decompressive SRS for benign perioptic tumors causing CCN is feasible using hypofractionation, representing a useful alternative to microsurgical resection.

Curative effects of head γ-SRT for the treatment of functional pituitary macroadenoma

The aim of the study was to examine the curative effects and proper radiotherapy plan of head γ-stereotactic radiotherapy (γ-SRT) for the treatment of functional pituitary macroadenoma. Clinical samples of 30 patients that underwent γ-SRT (radiotherapy group) and 26 patients that underwent pituitary adenoma resection via single nasal-sphenoidal approach (surgery group) were analyzed retrospectively and their curative effects were compared. The results showed that in the radiotherapy group, 12 cases accepted single fraction irradiation, with an average maximum diameter of tumor body of 1.8±0.6 cm, average volume of 0.6±0.4 cm³, average dose of the central point of 52.6±18.7 Gy, average dose of the peripheral point of 24.7±10.2 mGy, and isodose curve of 50–70%. The remaining 18 cases accepted multiple fraction irradiation, with an average irradiation of 3.7±1.6 times, maximum average diameter of tumor body of 4.3±1.8 cm, average volume of 4.8±2.7 cm³, average dose of the central point of 24.6±12.5 Gy, average dose of the peripheral point of 13.6±7.4 mGy, and isodose curve of 50–70%. Following treatment, the tumor volumes of patients in the radiotherapy group that received single and multiple irradiation were significantly reduced and the visual acuity and visual field were improved (p<0.05). The two groups were followed up for an average of 3.8 years, and the follow-up results showed that differences of the two groups on the tumor control, mortality and hypopituitarism rates were not statistically significant (p>0.05). In addition, the incidence of complications of the radiotherapy group was significantly decreased as compared to that of the surgery group (p<0.05). In conclusion, γ-SRT was safe and effective for the treatment of functional pituitary adenomas. Its curative effects were equivalent to that of the microscopic single nasal-sphenoidal approach with fewer complications.