Lack of Radiation Optic Neuropathy in 72 Patients Treated for Pituitary Adenoma

Radiation-Induced Retinopathy and Optic Neuropathy after Radiation Therapy for Brain, Head, and Neck Tumors: A Systematic Review

Background: Patients with brain, head, and neck tumors experience a decline in their quality of life due to radiation retinopathy and optic neuropathy. Little is known about the dose–response relationship and patient characteristics. We aimed to systematically review the prevalence of radiation retinopathy and optic neuropathy. Method: The primary outcome was the pooled prevalence of radiation retinopathy and optic neuropathy. The secondary outcome included the effect of the total radiation dose prescribed for the tumor according to the patient’s characteristics. Furthermore, we aimed to evaluate the radiation dose parameters for organs at risk of radiation retinopathy and optic neuropathy. Results: The pooled prevalence was 3.8%. No retinopathy was reported for the tumor’s prescribed dose of <50 Gy. Optic neuropathy was more prevalent for a prescribed dose of >50 Gy than <50 Gy. We observed a higher prevalence rate for retinopathy (6.0%) than optic neuropathy (2.0%). Insufficient data on the dose for organs at risk were reported. Conclusion: The prevalence of radiation retinopathy was higher compared to optic neuropathy. This review emphasizes the need for future studies considering retinopathy and optic neuropathy as primary objective parameters.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02133-z.

Treatment and prophylaxis of radiation optic neuropathy: A systematic review and meta-analysis

PURPOSE

Radiation optic neuropathy (RON) generally follows radiation therapy that exceed 50 Gy to the visual axis and occurs within three years of therapy. Currently, there are no universally accepted treatments or prophylaxis for RON. The review aimed to examine the efficacy of all treatments and prophylaxis for RON.

METHODS

MEDLINE, Embase, the Cochrane Library, and gray literature were searched to December 2020. Studies on treatment(s) and/or prophylaxis of RON were included. Results were meta-analyzed using a random-effects model. Primary outcomes included the proportions of patients who experienced improvement, no change, or worsening of visual acuity (VA) for each treatment. Secondary outcome was the incidence of RON for studies on prophylaxis.

RESULTS

Overall, 50 studies (n = 5397) were included. Meta-analysis (n = 1752) showed significantly lower incidence of RON in patients who underwent intravitreal anti-VEGF prophylaxis compared to control (RR 0.64, 95%CI [0.48, 0.86]) for uveal melanoma. Intravitreal anti-VEGF injections (n = 68), hyperbaric oxygen therapy alone (n = 14), and pentoxifylline (n = 5) resulted in improved or stable vision ≤1 logMAR in 54.5%, 42.9%, and 40.0% of patients, respectively. Systemic corticosteroids (n = 82), anticoagulants (n = 12), and systemic bevacizumab (n = 7) showed improved or stable vision ≤1 logMAR in 17.1%, 33.3%, and 14.3% of patients, respectively. Overall risk of bias was low, but evidence was limited to retrospective studies.

CONCLUSION

Intravitreal anti-VEGF injections reduced incidence of RON in irradiated uveal melanoma patients. Systemic corticosteroids, systemic bevacizumab, and warfarin alone are likely ineffective treatments. Early hyperbaric oxygen therapy and intravitreal anti-VEGF injections were most effective among those investigated and require further investigation.

Necrosis of the optic nerve and chiasm with safe radiation doses: Report of two rare cases

INTRODUCTION

Radiation-induced optic neuropathy (RION) is still a devastating complication of brain and skull base radiation that has no effective treatment up until today, thus uttermost caution must be taken in treating patients that brain radiotherapy is needed. We present two cases of RION that happened in seemingly safe radiation doses.

CASE DESCRIPTION

A 48-year-old female with a history of pleomorphic pituitary adenoma developed bilateral and painless loss of vision 10 months after radiation to the brain; the total radiation dose was 45 Gy in 25 fractions and no other risk factors of RION were found. Magnetic resonance imaging of the brain depicted bilateral prechiasmatic optic nerve enhancement with involvement of the optic chiasm. Treatment with high doses of corticosteroids was unsuccessful. A 62-year-old female with a history of lung adenocarcinoma and brain metastases presented with a 1-month history of decreased vision in both eyes. He had undergone whole-brain radiotherapy with a total dose of 30 Gy over 10 fractions and concurrent chemotherapy with cisplatin and pemetrexed. Brain magnetic resonance imaging (MRI) with contrast showed bilateral intracranial optic nerve enhancement.

CONCLUSIONS

This is the second case report of RION in a patient with a history of brain radiotherapy and concurrent chemotherapy with pemetrexed. History of chiasmal compression, concurrent use of chemotherapeutic agents, and high fraction size (despite the safety of total radiation dose) were possible contributing risk factors to develop RION in our cases. Hence, adjusting the radiation dose according to the presence of these risk factors is recommended.

Radiation-Induced Optic Neuropathy: Literature Review

Radiation-induced optic neuropathy (RION) is a rare disease caused by exposure of the optic nerves to radiation during radiotherapy procedures for head and neck tumours. The purpose of this study was to review and summarise the epidemiology, risk factors, clinical presentations, pathphysiology characteristics, diagnosis, and management of RION. Its occurrence is associated with cumulative doses of radiation above 50 Gy, presence of multi-morbidities and the presence of concomitant chemotherapy and radiotherapy. It manifests with acute, painless, and monocular loss of vision, and these symptoms appear late after the radiation exposure. The diagnosis of the disease occurs by exclusion and, mainly, by the clinical analysis of the case associated with the time of radiation exposure. Treatment does not seem promising and there is not an effective cure. In this review, we mainly focus on compiling existing information on the topic and providing knowledge for early diagnosis and more efficient treatment.

Radiation-Induced Optic Neuropathy: Clinical and Imaging Profile of Twelve Patients

BACKGROUND

Radiation-induced optic neuropathy (RON) is a form of delayed radionecrosis of the anterior visual pathways, which develops within months to years after external cranial irradiation and causes severe and irreversible vision loss. Small series reports have adequately documented its clinical features, but imaging characteristics have been less completely described.

METHODS

We accrued cases from the University of Michigan Neuro-Ophthalmology Clinic files and from cases coded as "radiation optic neuropathy" at the University of Michigan Medical Center between 1994 and 2017. All patients had undergone 3D-conformal linear accelerator (photon) external beam radiation. We collected clinical details of vision loss, including the temporal relationship to radiation. A single neuroradiologist (E.A.L.) evaluated all available magnetic resonance imaging (MRI) studies, noting the presence of enhancement, expansion, or volume loss of the optic nerves or chiasm, corresponding T2 signal abnormalities, and the absence of demyelination or confounding compressive lesions.

RESULTS

Twelve patients (15 eyes) met inclusion criteria. Vision loss was usually monocular at outset, but both optic nerves were eventually involved in 3 (25%) patients. Although usually sudden in onset, vision loss often declined slowly over many months, frequently to finger counting, or worse without recovery. An afferent pupillary defect was always present at the time of presentation. Most affected optic discs were pale at the time of first visual symptoms, indicating that subclinical optic nerve damage had been present for several weeks. The latency from completion of radiation to onset of vision loss ranged from 7 to 48 months (average: 18 months). In 2 patients, radiation was delivered to the whole brain, rather than being limited to the anterior visual pathway. MRI typically displayed a discrete region of enhancement of the affected prechiasmatic optic nerve, often with expansion and high T2 signal in the enhancing segment. In 3 affected eyes, enhancement was apparent on imaging completed 3-6 weeks before the onset of vision loss. In one patient, segmental prechiasmatic enhancement became evident only on repeat MRI completed 7 months after vision loss. The duration of enhancement among 9 eyes with follow-up MRIs was at least 2 months, but in one case, enhancement was still present on a study performed 17 months after treatment.

CONCLUSIONS

This study further delineates the profile of RON. Visual loss is often acute, profound, and monocular but may decline slowly after acute onset and later affect both optic nerves. High-resolution MRI of the optic nerves usually will display enhancement of a discrete segment of the intracranial prechiasmatic optic nerve, often with accompanying expansion and T2 hyperintensity. In some cases, these imaging features may precede vision loss. They may be subtle or appear after vision loss. Enhancement lingers for a wide interval, ranging in this study from 2 to at least 17 months. Recognition of these imaging characteristics assists in confirmation of the diagnosis of RON.

Catastrophic vision loss from radiation-induced optic neuropathy

A 68-year-old woman presented with profound vision loss of 2-month duration in the right eye and 1-week duration in her left eye. This occurred in the context of craniopharyngioma that was twice resected and irradiated (54 Gy in 30 fractions) 9 months before her presentation. Ophthalmological examination revealed hand motion vision in the right eye and light perception vision in the left eye with poorly reactive pupils and bilateral optic disc pallor. A non-contrast MRI of the brain and sella showed significant reduction of the sellar mass. A repeat MRI of the brain and orbits with gadolinium showed pre-chiasmatic enhancement of both optic nerves. The diagnosis of radiation-induced optic neuropathy was made. Despite treatment with high-dose intravenous corticosteroids, 19 sessions of hyperbaric oxygen therapy, and 3 doses of intravenous bevacizumab, her vision worsened to no light perception in both eyes.

Factors Associated with Occurrence of Radiation-induced Optic Neuropathy at "Safe" Radiation Dosage

BACKGROUND

Radiation-induced optic neuropathy (RION) is a rare, and often visually devastating, complication of radiation therapy (RT) near the anterior visual pathways.

METHODS

A retrospective case series of patients who developed RION at a tertiary medical center, followed by a case-control study comparing RION cases with matched controls who received RT.

RESULTS

Thirteen patients (18 eyes) with RION were identified. Radiation modalities included external beam photon radiation, whole brain radiation, stereotactic radiosurgery, proton beam, and unknown. Most patients received doses below published "safe" thresholds (<55 Gy; <8-10 Gy for stereotactic radiosurgery). There was no statistically significant difference in prevalence of vasculopathic factors between cases and controls; on subgroup analysis in three patients who received surprisingly low radiation doses, smoking (p=0.05) and hypertension (p=0.02) appeared more prevalent.

CONCLUSION

RION can occur at doses below published "safe" thresholds and with different RT modalities. Smoking and hypertension might be risk factors for RION.

Organ-sparing radiation therapy for head and neck cancer

To improve locoregional tumor control and survival in patients with locally advanced head and neck cancer (HNC), therapy is intensified using altered fractionation radiation therapy or concomitant chemotherapy. However, intensification of therapy has been associated with increased acute and late toxic effects. The application of advanced radiation techniques, such as 3D conformal radiation therapy and intensity-modulated radiation therapy, is expected to improve the therapeutic index of radiation therapy for HNC by limiting the dose to critical organs and possibly increasing locoregional tumor control. To date, Review articles have covered the prevention and treatment of radiation-induced xerostomia and dysphagia, but few articles have discussed the prevention of hearing loss, brain necrosis, cranial nerve palsy and osteoradionecrosis of the mandible, which are all potential complications of radiation therapy for HNC. This Review describes the efforts to prevent therapy-related complications by presenting the state of the art evidence regarding advanced radiation therapy technology as an organ-sparing approach.

Optic neuropathy following radiotherapy for Cushing's disease: case report and literature review

Radiation-induced optic neuropathy is a rare adverse effect of radiotherapy applied for the treatment of pituitary adenomas. We report a patient with a recurrent adrenocorticotrophin secreting pituitary adenoma who received external beam irradiation after failing surgical and medical therapy. Sixteen months after radiotherapy, the patient was presented with declining visual acuity, and radiation-induced optic neuropathy was diagnosed. Despite treatment with glucocorticoids and hyperbaric oxygen, her vision did not improve. The pathophysiology, prevention and treatment of radiation-induced optic neuropathy, including the efficacy of hyperbaric oxygen therapy are reviewed.

Radiotherapy is Not Associated With Reduced Quality of Life and Cognitive Function in Patients Treated for Nonfunctioning Pituitary Adenoma

PURPOSE

To assess the influence of different treatment modalities on long-term health-related quality of life (HR-QoL) and cognitive problems among patients who had been treated for nonfunctioning pituitary adenoma (NFA).

METHODS AND MATERIALS

Eighty-one patients (49 men and 32 women, aged 55 +/- 10 years) with a minimal follow-up period of 1 year after treatment for NFA participated in this cross-sectional study. Sixty-two patients were initially treated by transsphenoidal surgery and 19 by craniotomy. Subsequently, 45 of these 81 subjects (56%) received additional radiotherapy (RT) after surgery because of a tumor remnant or regrowth. All subjects filled in standardized questionnaires measuring HR-QoL, depression, fatigue, and cognitive problems.

RESULTS

Patients who underwent additional RT more frequently underwent a craniotomy and were younger at surgery, but not at entering this study. They also used more hormonal substitution. Most HR-QoL domains showed a similar score in patients who underwent RT when compared with patients who did not receive RT. However, vitality and physical functioning proved to be better in RT subjects, and RT subjects also had better scores for depression and physical and mental fatigue (all p < 0.05). Some aspects of HR-QoL of patients who have been successfully treated for NFA are reduced compared with the normal population, but this was much more pronounced in the group that did not receive RT. In multivariate analysis, RT remained significantly associated with improved HR-QoL. No differences in cognitive function scores were observed.

CONCLUSION

Postoperative RT in patients with NFA is not associated with reduced quality of life or cognition when compared with surgery alone.

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.

Clinical results of conformal radiotherapy and radiosurgery for pituitary adenoma

Radiation therapy provides a valuable adjunct to surgery as well as a viable management alternative to surgery for pituitary adenomas. The availability of conformal radiotherapy has dramatically reduced complication rates, and the advent of radiosurgery has reduced the latency of response in these patients. Although extended follow-up is needed to elucidate the long-term outcomes of these treatments, they are likely to be a permanent part of the therapeutic armamentarium for these patients for the near future.

Pituitary radiotherapy: current controversies

External beam radiotherapy has been used extensively in the management of patients with pituitary disease. However, in view of advances in the techniques of radiotherapy planning and administration, neurosurgery and pharmacological manipulation of the pituitary, there are a growing number of questions and controversies surrounding the current and future use of pituitary radiotherapy in the management of pituitary disease.

Pegvisomant therapy in pituitary gigantism: successful treatment in a 12-year-old girl

OBJECTIVE

The use of a growth hormone (GH) receptor antagonist, pegvisomant has shown great promise in adults with acromegaly, but experience in paediatric patients is lacking. We aimed to describe the results of pegvisomant therapy in a 12-year-old girl with an aggressive GH-secreting pituitary tumour.

DESIGN

To evaluate the ability of pegvisomant therapy to control the effects of peripheral GH excess in a case of pituitary gigantism.

METHODS

Pegvisomant was introduced at 10 mg/day, given subcutaneously, and gradually increased to 20 mg/day until serum IGF-I was normal for age.

RESULTS

A large pituitary adenoma with suprasellar extension was diagnosed in a 12-year-old girl with progressive tall stature (178 cm), GH hypersecretion without suppression during oral glucose loading (nadir serum GH, 90 mU/l), high serum IGF-I and serum prolactin levels. Surgical extirpation was not possible because tumour tissue was fibrous and adherent to the optical nerves. Histological examination showed a mixed GH- and prolactin-secreting adenoma with lymphocytic infiltration of B and T cells. Treatment with a dopamine agonist, cabergoline, normalized serum prolactin, but GH secretion was resistant to both somatostatin analogue, octreotide and cabergoline. Radiation followed by pegvisomant therapy titrated up in dose to 20 mg/day led to a marked reduction in GH secretion and normalization of IGF-I, and to growth arrest and improvement of well-being.

CONCLUSIONS

We suggest that treatment in pituitary gigantism with pegvisomant is safe and may normalize IGF-I levels and effectively stop growing.

Sustained visual recovery after treatment with intrathecal methotrexate in a case of optic neuropathy caused by chronic lymphocytic leukemia

A 68-year-old woman with chronic lymphocytic leukemia (CLL) had acute optic neuropathy associated with cerebrospinal fluid evidence of meningeal spread of CLL. There was no evidence of a hematologic relapse. After undergoing four weekly doses of intrathecal methotrexate, vision improved dramatically and spinal fluid became normal. Four years later, she has near normal vision in the affected eye and remains in hematologic remission. This is the first reported case of successful treatment of optic neuropathy in CLL with intrathecal methotrexate alone.