Acute dysthyroid optic neuropathy exacerbated by orbital radiotherapy

A 76-year-old lady presenting with acute dysthyroid optic neuropathy (DON) was stabilised with systemic intravenous methylprednisolone (IVMP). Two separate attempts at a treatment course of orbital radiotherapy (OR) were commenced and subsequently abandoned as there was an acute worsening of her DON during OR, despite cover with oral glucocorticoids and subsequently IVMP. The patient underwent urgent orbital decompression which normalised her vision and optic neuropathy. Our case likely represents worsening of DON due to soft tissue swelling secondary to OR despite cover with IVMP in a patient previously responsive to IVMP alone. Some authors advocate the use of OR in active DON as either a surgery delaying or surgery sparing alternative. This case report illustrates the rare risk of transiently worsening DON with OR. We highlight the need for close monitoring of optic nerve function if OR is utilised in this patient group.

Approche épidurale temporopolaire transcaverneuse transpétreuse. Technique chirurgicale et indications

BACKGROUND AND PURPOSE

Several selective approaches have been recommended for access to the petroclival region (PCR). However, locoregional extension of the tumor may necessitate more extensive procedures. Dissections from injected specimens allowed us to describe the different osteodural triangles that are exposed to provide an extensive access to the PCR.

METHOD

The bony step included a temporopterional flap and exposure of the paraclinoid carotid after removal of the anterior clinoid process. The sphenoid wing was then extensively drilled, exposing the foramen rotundum and ovale. An anterior petrosectomy was subsequently performed. The dura propria of the cavernous sinus was elevated as far as the Meckel cave. The sylvian fissure was also opened. Then, the temporobasal dura and the dura from the posterior surface of the petrous bone were opened and the superior petrosal sinus was coagulated and divided. The tentorium was divided toward its free edge.

RESULTS

Via this approach, cranial nerves from the olfactory tract to the acousticofacial bundle are exposed. In the same way, the ventral and lateral surface of the pons is identified.

CONCLUSION

The epidural temporopolar transcavernous transpetrous approach is useful to expose during the same procedure, elements of the posterior and middle cranial fossa. It is of particular value when managing tumors simultaneously involving the PCR, the parasellar, and the suprasellar regions.

[Radiation therapy for thyroid-associated ophthalmopathy]

OBJECTIVE

To observe indication and effectiveness of radiation therapy (RT) in the treatment of the patients with thyroid-associated ophthalmopathy (TAO).

METHODS

23 patients of TAO who received RT in Sichuan University were collected from 1992 to 2004. Among those patients, 9 cases of infiltrative exophthalmos and 14 cases of compressive optic neuropathy were ineffectively with glucocorticoid treatment or could not treated with glucocorticoid, or could not perform orbital decompression due to severe diabetic mellitus or hypertension, or feared to receive the operation, all of patients were active ophthalmopathy and with short duration. Outer orbital radiation was applied using linear accelerator with Donaldson's method, radiation treatment fields was 4 cm x 5 cm, exposure energy was 2 GY fractions with total of 20 GY. In 11 cases with severe inflammation prednisone was administered during radiotherapy. Photos and CT scan were taken for each patient before and after RT.

RESULTS

Visual acuity (VA) of the patients was improved from before RT 0.04 - 0.2 to after RT 0.1 - 0.8 in 14 cases of compressive optic neuropathy. Extraocular muscle of patients decreased in size confirmed by CT scan. VA improvement was correlated with the degree of extraocular muscle decreased in size. Eyelid and conjunctive swelling, eyelid incompletely closure, exposure keratitis, limitation of motion and proptosis were improved after RT in 9 patients with infiltrative exophthalmos. Following up the patients for 1 - 3 years, it was found that VA decreased in 3 cases and inflammation recurred in 4 cases, eyelids could not closed in 2 cases after RT.

CONCLUSIONS

RT could be used in severe, active cases of TAO. If there is severe inflammation, steroids could be combined with RT therapy.

Metastatic pituitary tumor from renal cell carcinoma treated by fractionated stereotactic radiotherapy--case report

A 63-year-old man presented with rapidly progressive visual field deficit and hypopituitarism including diabetes insipidus, 8 years after treatment for a renal cell carcinoma. Neuroimaging studies revealed a dumbbell-shaped pituitary mass that had destroyed the sellar floor and abutted against the optic apparatus. Fractionated stereotactic radiotherapy (SRT), employing computer-image integration techniques and a frame that could be relocated to facilitate a fractionated dosing scheme, was carried out under a plan for reducing the treatment risk to the optic apparatus. Three months later, the patient exhibited marked improvement in the visual field deficit and visual acuity concomitant with a reduction in tumor volume. Magnetic resonance imaging of the sellar region confirmed striking shrinkage of the metastasis. His neurological status remained stable at 12 months after the SRT with no complications. Fractionated SRT appears to be effective for preserving or improving the residual vision in patients with visual loss secondary to metastatic tumor of the pituitary gland, and may result in a longer and better quality of life.

Radiotherapy for Moderate-to-Severe Graves?? Ophthalmopathy

PURPOSE

The purpose of this review is to quantify the response to radiotherapy delivered early in the active inflammatory phase of moderate-to-severe Graves' ophthalmopathy.

MATERIALS AND METHODS

A retrospective review of radiotherapy delivered early in the active phase of Graves' ophthalmopathy was performed. All 47 cases had moderate-to-severe ophthalmopathy, and 30 cases had optic neuropathy. Variables examined included exophthalmos, color vision, and resistance to retropulsion. Statistical analyses comparing these variables at presentation and at 3 and 6 months after radiotherapy were performed. Subset analyses comparing responses of patients with symptoms lasting longer or less than 6 months were also performed.

RESULTS

At 6 months after radiotherapy, there was improvement in exophthalmos in 74.5% of cases and improvement in retropulsion in 83.0%, and all cases of previous color deficiency improved. The mean improvement in exophthalmos was 1.38 mm, color vision was two plates, and retropulsion was 1 grade. On subset analyses, there was a trend toward greater improvement in patients treated earlier in the course of their symptoms.

CONCLUSIONS

Radiotherapy may play an important role in the treatment of Graves' ophthalmopathy, especially for patients with optic neuropathy. Early intervention (symptoms < 6 months) with radiotherapy may be the optimal timing for this treatment.

Management of thyroid eye disease

Thyroid eye disease (TED) is the most frequent extrathyroidal manifestation of Graves' disease. In most instances it is mild and non-progressive, but in 3%-5% of cases it is severe. Non-severe TED requires only supportive measures, such as eye ointments, sunglasses and prisms. By contrast, severe TED requires aggressive treatment, either medical (high-dose glucocorticoids, orbital radiotherapy) or surgical (orbital decompression). The choice of treatment relies on the assessment of both TED severity and activity. Removal of controllable risk factors, especially cigarette smoking, is important to improve the course and the therapeutic outcome. A coordinated approach to the treatment of hyperthyroidism and TED is also required. Novel promising treatments, to be verified in large series of patients, include somatostatin analogues and cytokine antagonists.

Intraocular pressure changes after treatment for Graves' orbitopathy

OBJECTIVE

To evaluate the change in intraocular pressure (IOP) in subjects with Graves' orbitopathy (GO) after orbital decompression, strabismus surgery, and orbital radiation.

DESIGN

Retrospective case review.

METHODS

The charts of 172 consecutive subjects from the Neuro-ophthalmology Service at Wills Eye Hospital (Philadelphia, PA) with GO who underwent either orbital decompression, strabismus surgery, or orbital radiation between 1994 and 1999 were analyzed. Subject age, gender, diagnosis of glaucoma in either eye, use of systemic steroids or topical glaucoma medications, procedure performed, and the preoperative and postoperative IOP (in primary position and upgaze) were evaluated.

RESULTS

Of 116 eyes that underwent orbital decompression, the mean preoperative IOP was 21.6+/-4.6 mmHg (standard deviation) in primary position and 27.9+/-6.8 mmHg in upgaze. The postoperative IOP was 17.5 mmHg +/- 3.0 mmHg in primary position and 20.1+/-4.7 mmHg in upgaze, a decrease in IOP of 18.9% in primary position and 27.9% in upgaze (P<0.001). Subjects taking glaucoma medication or who had IOP greater than 21 mmHg demonstrated a significantly (P<0.001) greater reduction in IOP postoperatively. The mean preoperative IOP in the 32 subjects who had strabismus surgery was 18.5+/-2.8 mmHg (primary position), and 24.7+/-4.3 mmHg (upgaze). Postoperative IOP was 16.1 mmHg (primary position) and 16.9 mmHg (upgaze), a decrease of 2.4 mmHg (13.3%, P<0.01 in primary position) and 7.8 mmHg (31.2%, P<0.01 in upgaze). There was no statistically significant reduction in IOP after orbital radiation.

CONCLUSIONS

In the selected subgroup of subjects with GO who required intervention, orbital decompression and strabismus surgery resulted in a significant reduction in IOP in the early postoperative period, especially in subjects with preoperative IOP greater than 21 mmHg.

Objective evaluation of improvement in optic neuropathy following radiation therapy for thyroid eye disease

PURPOSE

While the literature supports the use of radiation therapy for thyroid eye disease, it does not sufficiently describe in detail the results of radiation therapy for optic neuropathy associated with thyroid eye disease. The objective of this study is to quantify the changes in parameters of optic neuropathy after orbital irradiation for thyroid eye disease.

METHODS AND MATERIALS

Twelve consecutive patients with optic neuropathy from thyroid eye disease were followed by a single neuro-ophthalmology practice and treated by one radiation oncologist with radiation therapy from 1991 through 1995. All cases were prospectively followed for visual acuity, color vision, mean deviation, and/or foveal sensitivity and afferent pupillary defect. All patients received 2000 cGy in 10 fractions with megavoltage irradiation to the orbits.

RESULTS

Ten of 12 patients were evaluated for follow-up (one moved out of this country and one had a stroke, which confounded interpretation of examination results). An analysis was performed retrospectively while treatment and evaluation remained uniform. Five men and five women formed the basis of this study with a median age of 60 years (35-76 years). Nineteen eyes were evaluated for thyroid optic neuropathy. Improvement in optic nerve function occurred in eight of ten patients. Improvement was seen either during radiotherapy or within 2 weeks of completion. No long-term adverse effects were noted.

CONCLUSION

This study objectively demonstrates improvement in optic neuropathy from radiation therapy for thyroid eye disease.

Visual pathway glioma: an erratic tumour with therapeutic dilemmas

OBJECTIVE

Our experience in children with visual pathway glioma (VPG) was reviewed to delineate its clinical characteristics.

DESIGN

The charts and imaging studies of 21 children with VPG who were followed up in our centre during the last 12 years were reviewed and summarised.

RESULTS

VPG accounted for 13.1% of all brain tumours treated during this period. Sixty two per cent of the children with VPG had neurofibromatosis type 1 (NF-1). Among these, more than 60% were detected as part of routine work up. In some cases decreasing visual function preceded the appearance of the VPG on imaging studies. Tumour growth rate was markedly unpredictable. All treatment modalities employed led to tumour shrinkage and stabilisation for a variable period, but none was successful in totally eradicating the tumour. Complications were less severe after chemotherapy compared with radiotherapy. Three children died, none with NF-1, with a globular hypothalamic/chiasmatic tumour and accompanying electrolyte abnormalities.

CONCLUSIONS

NF-1 is a favourable prognostic marker for VPG. Whenever possible a period of observation is necessary before treatment is initiated, during which time tumour size and visual function should be closely followed up; an untoward change in either of these is an indication for the start of treatment, preferably chemotherapy first. The combination of a globular hypothalamic/chiasmatic glioma and electrolyte abnormalities in a child without NF-1 are related to a poor prognosis.

Management of pilocytic astrocytoma

Pilocytic astrocytoma, when totally resected, has a favorable outcome compared to other astrocytomas. However, when residual tumor remains, the prognosis is less satisfactory. Our study addressed the issues of prognosis in cases of residual tumor and the effect of post-surgical radiation therapy on tumor recurrence. We analyzed 41 cases of pilocytic astrocytoma which were diagnosed by histologic examination. Twenty-six patients were 15 years old or younger, and 15 patients were 16 years old or older. An analysis of the relationship between age and tumor location revealed a cerebellar predominance in both age groups; however, there were more brain stem and basal ganglia tumors among adults. Overall prognosis was favorable, with a 2-year survival rate of 97.6%, 94.6% at 5 years, and 94.6% at 10 years. Children had a better prognosis than adults due to more favorable tumor location. Gross total resection resulted in the best prognosis, i.e., no recurrence during a 10-year follow-up period. Radiation treatment after surgery suppressed residual tumor. We concluded that the best treatment for pilocytic astrocytoma is: 1) total resection, if possible, followed by 2) irradiation of any residual tumor to suppress recurrence.

Cerebro-vasculopathy and malignancy: catastrophic complications of radiotherapy for optic nerve glioma in a von Recklinghausen neurofibromatosis patient

The authors report a unique case of a patient with intraorbital optic nerve glioma and von Recklinghausen neurofibromatosis who developed cerebro-vasculopathy and malignant transformation in the orbit 18 months after radiotherapy treatment. The case is an important reminder of the possibly increased susceptibility of von Recklinghausen neurofibromatosis patients to the complications of radiotherapy.

Metastasis to the optic nerve: clinicopathological correlations

OBJECTIVE

To describe the clinical, radiologic and histopathological features of two cases of carcinoma metastatic to the optic nerve with different pathways of spread.

DESIGN

Chart review.

SETTING

Oncology clinic in Montreal.

PATIENTS

One patient previously treated for breast carcinoma and one patient previously treated for small-cell carcinoma of the lung.

RESULTS

The patient with breast carcinoma was found to have an elevated mass involving her right optic nerve head. This finding was confirmed by B-scan ultrasonography. The other patient initially presented with left retinal metastasis and subsequently manifested massive secondary involvement of the ipsilateral optic nerve, documented by computed tomography. Both patients were initially treated with radiotherapy to the eye and orbit, but postmortem histopathological study showed that this treatment had little effect on the tumour.

CONCLUSIONS

The histopathological observations suggest that if radiotherapy is to be used in the treatment of metastasis to the optic nerve, the dosage of radiation should be higher than that recommended for the treatment of choroidal metastasis.

Fetal dose estimates for radiotherapy of brain tumors during pregnancy

PURPOSE

To determine clinically the fetal dose from irradiation of brain tumors during pregnancy and to quantitate the components of fetal dose using phantom measurements.

METHODS AND MATERIALS

Two patients received radiotherapy during pregnancy for malignant brain tumors. Case 1 was treated with opposed lateral blocked 10 x 15 cm fields and case 2 with 6 x 6 cm bicoronal wedged arcs, using 6 MV photons. Fetal dose was measured clinically and confirmed with phantom measurements using thermoluminescent dosimeters (TLDs). Further phantom measurements quantitated the components of scattered dose.

RESULTS

For case 1, both clinical and phantom measurements estimated fetal dose to be 0.09% of the tumor dose, corresponding to a total fetal dose of 0.06 Gy for a tumor dose of 68.0 Gy. Phantom measurements estimated that internal scatter contributed 20% of the fetal dose, leakage 20%, collimator scatter 33%, and block scatter 27%. For case 2, clinical and phantom measurements estimated fetal dose to be 0.04% of the tumor dose, corresponding to a total fetal dose of 0.03 Gy for a tumor dose of 78.0 Gy. Leakage contributed 74% of the fetal dose, internal scatter 13%, collimator scatter 9%, and wedge scatter 4%.

CONCLUSIONS

When indicated, brain tumors may be irradiated to high dose during pregnancy resulting in fetal exposure < 0.10 Gy, conferring an increased but acceptable risk of leukemia in the child, but no other deleterious effects to the fetus after the fourth week of gestation. For our particular field arrangements and linear accelerators, internal scatter contributed a small component of fetal dose compared to leakage and scatter from the collimators and blocks, and 18 MV photons resulted in a higher estimated fetal dose than 6 MV photons due to increased leakage and collimator scatter. These findings are not universal, but clinical and phantom TLD measurements estimate fetal dose accurately for energies < 10 MV and should be taken for each pregnant patient considered for treatment to confirm and document acceptable dose.

A clonal translocation t(10;21) in an optic glioma of a patient with neurofibromatosis type 1 (NF 1)

An 11-year-old boy affected by neurofibromatosis type 1 is presented with severely impaired vision on the right eye (0.1). MRI demonstrated a 2.3 x 1.8 cm tumour of the optic chiasma. After open biopsy cytogenetic analysis was performed on primary cultures of this optic glioma (grade I). A clonal translocation t(10;21)(q21.2;21.1) was detected in 66% of the metaphases analysed. The boy received fractioned irradiation with a total tumour dose of 60 Gy. The ultimate MRI taken 18 months after radiotherapy showed no residual tumour. The vision on the right improved to 0.2, but decreased on the left to 0.6. The patient attends high school with no impairment in his daily life.

Optic nerve glioma presenting as a huge intrasellar mass. Case report

We report the case of a twelve-year-old boy who presented with visual impairment and headache and was found to harbour a purely intrasellar cystic pilocytic astrocytoma originating from proximal left optic nerve. The mass was explored transcranially and decompression of the optic apparatus and subtotal resection of the cyst wall was accomplished. The patient received post-operative radiotherapy and stays symptom-free after two years. A review of the literature revealed six cases of optic pathway astrocytomas associated with cyst formation. Our case appears as the first case of an optic glioma to present as an intrasellar mass.

Surgery of giant gliomas of chiasma and IIIrd ventricle

During a period of 17 years (from 1976 till now) 45 patients with giant gliomas of the chiasma and the IIIrd ventricle out of a total amount of 120 patients with hypothalamic gliomas were operated. The following classification of tumours was used: I) tumours with predominant anterior growth; II) tumours which infiltrate chiasma and penetrate into the IIIrd ventricle; III) gliomas of the floor of the IIIrd ventricle and the chiasma, growing into the ventricle cavity; IV) tumours of the chiasma, optic tract and thalamus. The authors come to the conclusion, that surgical removal of giant tumours of the chiasma and the IIIrd ventricle, though risk, may result in an improvement or stabilisation of visual functions (77%) and a long period free from recurrencies (9.5%). The postoperative period is relatively favourable and the mortality is low (6%). The main contraindication in our opinion is a wide infiltration of adjacent brain structures by the tumour and spreading along both optical tracts. We consider the giant size of a tumour in itself a sufficient indication for surgery.

Moyamoya phenomenon after radiation for optic glioma

The role of radiotherapy in the management of patients with optic pathway glioma is controversial. In a series of patients with optic pathway glioma treated at The Hospital for Sick Children in Toronto, five children were encountered who developed moyamoya phenomenon after radiotherapy. A retrospective review of the medical records was undertaken in order to assess the relationship between optic pathway glioma, neurofibromatosis type 1 (NF1), radiation therapy, and moyamoya disease. Forty-seven patients with optic pathway glioma were operated on at The Hospital for Sick Children between 1971 and 1990. The moyamoya phenomenon did not occur in any of the 19 patients not receiving radiotherapy. Among the 28 patients who received radiotherapy, five developed moyamoya disease (two of 23 without NF1 and three of five with NF1). There was a statistically significant relationship between radiotherapy and moyamoya disease when the analysis was stratified according to the presence of NF1 (Mantel-Haensel chi-squared test 15.23, p < 0.01). The high incidence of moyamoya disease (three of five cases, or 60%) in patients with NF1 who have undergone radiotherapy suggests a synergistic relationship that should be considered when formulating a treatment plan for NF1 patients with optic pathway glioma.

Metastatic lesion of the optic nerve

Metastatic disease to the optic nerve is uncommon. Optic nerve involvement has been described as an extension from choroidal, retinal, orbital, or central nervous system metastatic foci. Isolated optic nerve metastatic disease is extremely rare. We present the case of an isolated circumscribed metastatic lesion to the retrobulbar portion of the optic nerve detected radiographically.

Orbital fat removal. Decompression for Graves orbitopathy

BACKGROUND

Orbital decompression has been used to describe surgical procedures that remove some portion of the orbital walls to reduce pressure on the orbital contents. Substantial morbidity associated with these procedures includes infraorbital anesthesia, worsened extraocular motility, globe displacement, and blindness. The authors believe that orbital contents also may be decompressed by removing orbital fat.

METHODS

Eighty-one patients with nonactive Graves orbitopathy were selected for orbital fat decompression based on the presence of proptosis and associated signs and symptoms to avoid bone removal. Soft-tissue analysis by computed tomography (CT) scan showed distended pockets of fat extending into the intraconal space, which were removed through medial-upper and lateral-lower anterior orbitotomies. Decompression with bone removal was reserved for those few patients with compressive optic neuropathy unresponsive to medical treatment and those patients with residual deforming exophthalmos after fat removal.

RESULTS

One hundred fifty-eight fat decompressions were performed on 81 patients over 9 years. The authors measured an average reduction in proptosis of 1.8 mm (range, 0-6.0 mm). The greatest average reduction in proptosis (3.3 mm) was produced in patients with preoperative Hertel measurements of greater than 25.0 mm. Morbidity was limited to temporary motility impairment of the inferior oblique in two patients.

CONCLUSION

The concept of orbital decompression can include removal of orbital fat to reduce proptosis, eliminate symptoms, and improve appearance with far less morbidity than when bone decompression is used as the primary decompressive procedure.

Acute lymphoblastic leukemia following optic glioma treated by radiotherapy and surgery

A 14-year-old girl was diagnosed as having acute lymphoblastic leukemia following 5000 cGy cranial radiotherapy for treatment of optic glioma. In the absence of underlying predisposing factors, development of acute leukemia was attributed to the oncogenic effect of radiation.

Optic glioma in children: surveillance, resection, or irradiation?

Eighty-seven consecutive children with newly diagnosed optic glioma were managed at University of Toronto hospitals 1958-1990. Overall the 10-year survival, relapse-free survival and freedom from second relapse rates were 84%, 68% and 85%. Twenty-seven patients relapsed or progressed, of whom 40% were free of a second relapse 10 years after the first relapse. Fourteen patients had a second relapse. Thirteen are dead. None survived 5 years after second relapse. Patients with anteriorly located tumors (N = 35), which involved the optic nerve, or chiasm and optic nerves, fared better than those with posteriorly located tumors (N = 52) with spread beyond the chiasm, 10-year survival 95% versus 76%, (p = .02), 10-year relapse-free survival 80% versus 59% (p = .02), respectively. For posterior tumors primary irradiation was more effective than primary subtotal resection for prevention of subsequent relapse, 10-year relapse-free survival 75% versus 41% (p = .02), but salvage therapy was, in part, successful and multivariate analysis of prognostic factors influencing survival for posterior tumors indicated that neither primary resection nor primary irradiation were significant factors. For first relapse, primary irradiation and the presence of neurofibromatosis were the significant favorable factors. Since 1977 and for posterior optic glioma subtotal resection or surveillance were used in 21/29 (72%) patients compared with 4/23 (17%) previously. Ten-year survival rates before and after 1977 were 78% and 67% and 10-year relapse-free survival 64% and 56%, respectively.

Radiotherapy resolves leukemic involvement of the optic nerves

A 40-year-old woman with acute lymphoblastic leukemia had a visual disturbance OD. The optic disc was slightly swollen in the right fundus, and blast cells in the cerebrospinal fluid were found. Radiotherapy to the brain and orbit resolved these findings. Five months later, visual acuity decreased OS. Radiotherapy also was effective in treating the leukemic involvement of the optic nerve.

Precision radiation therapy for optic nerve sheath meningiomas

A more precise radiation therapy technique to treat unilateral optic nerve sheath meningioma is presented. It uses an immobilization device to align the ipsilateral optic nerve with a vertical axis and employs three small half-beam blocked fields to deliver radiation to a small conformal volume, thereby reducing the dose to the optic chiasm and the contralateral optic nerve. Three patients were successfully treated with this technique, and a fourth patient with optic nerve glioma was also treated in a similar fashion and was included in this study. The new technique irradiates a much smaller volume of tissue to high dose levels: 58 cm3 is irradiated to the 80% isodose level and only 18 cm3 to the 95% level. In contrast, the opposed lateral technique irradiates 171 and 73 cm3 to these levels, respectively. Thus, a considerable reduction in the volume of normal tissue irradiated was accomplished. Doses to the pituitary and contralateral optic nerve were 4% of the treatment dose for the new technique, whereas these doses were 40% and 100% for opposed laterals and 10% and 3% for wedged pair, respectively. The average setup error for this technique was very small, 50% of the setups measured were less than 1 mm off, and 92.5% were less than 3 mm off. However, for the conventional setups without a mask, only 21% of the setups were less than 1 mm off and 55% less than 3 mm off. We recommend this technique for localized unilateral optic nerve sheath meningioma and other optic nerve lesions that may require radiation therapy.

[Total removal of hypothalamic glioma 15 years after irradiation of right optic glioma]

Hypothalamic glioma was found in a 17 year old male patient 15 years after irradiation of right optic glioma. It was totally removed by surgery. He was first admitted to Ryukyu University Hospital at the age of 1 year and 11 months, with right exophthalmos and visual disturbance. Diagnosis was anterior type of right optic glioma. This was treated by irradiation (47 Gy). Follow-up CT scans revealed no regrowth in intraorbital and intracranial regions. At the age of 17 years, CT scan and MRI showed an enhanced mass in the hypothalamus above the suprasellar cistern. Total removal was performed by bifrontal interhemispheric trans-lamina terminalis approach. Histological diagnosis was pilocytic astrocytoma. Postoperatively, consciousness remained disturbed for 3 weeks because of infarction in the bilateral medial nucleus of the thalamus. Radical excision of hypothalamic glioma was reviewed in the literature. We concluded that such excision has a potentially good outcome, and should be attempted when circumstances indicate its feasibility.

Optic pathway tumors

Overall, the majority of patients with optic pathway tumors will have stable disease regardless if they are radiated or receive chemotherapy. This is a very indolent tumor system and, for the most part, not a threat to life. Because of this, issues regarding appropriate therapeutic approaches have yet to be resolved. Most agree that in patients with progressive visual loss and tumor limited to the orbit, surgery can be associated with a cure. The downside is the loss of vision associated with surgical extirpation. Radiation rather than surgery has been the mainstay of treatment for intracranial tumors of the optic pathway. To eliminate side effects associated with radiotherapy in the young child, chemotherapy may be the more considered choice. However, on escape of control, i.e., conversion of stable disease to progressive disease, radiotherapy should be considered.

Efficacy and complications of radiotherapy of anterior visual pathway tumors

A progressive disturbance in visual acuity or visual field, along with an unexplained optic nerve atrophy, suggests the possibility of a tumor. Tumors that frequently affect the anterior visual pathway include primary optic nerve sheath meningiomas, intracranial meningiomas, optic gliomas, pituitary tumors, and craniopharyngiomas. The location of these tumors sometimes prohibits a complete surgical excision that might jeopardize the visual system. Radiation therapy, however, can be beneficial in these cases. This article reviews the indications for radiotherapy of tumors that involve the anterior visual pathway, along with the possible complications. Cases that present the effect of radiation therapy and radiation damage are presented.

Growth and endocrine disorders in optic glioma

Hypothalamo-pituitary function in children with optic glioma may be impaired by the tumour itself and by the high cranial radiation doses used in treatment. This study evaluates the effect of optic glioma and its treatment on patient growth and pubertal development. Twenty-one patients (13 boys, 8 girls), treated for optic glioma by cranial irradiation (45-55 Grays) at a mean age of 5.4 years, were evaluated before (n = 10) and/or after (n = 21) irradiation. Growth hormone (GH) deficiency was present in only 1 patient tested before irradiation and in all patients after irradiation. Precocious puberty occurred in 7/21 cases, before irradiation in 5 patients and after irradiation in 2 patients. The cumulative height loss during the 2 years after irradiation was 0.2 +/- 0.2 SD (m +/- SEM) in 7 patients with precocious puberty and 1.1 +/- 0.2 SD in 14 prepubertal patients (P less than 0.01). The corresponding bone age advance over chronological age, evaluated 1-3 years after irradiation, was 1.1 +/- 0.5 and -0.7 +/- 0.3 year in the two groups (P less than 0.01). The mean height loss between time of irradiation and the final height was 2.3 +/- 0.6 SD (n = 6). Primary amenorrhoea, associated with low oestradiol levels, occurred in two of the three girls of pubertal age. These data indicate that the high dose of cranial radiation used to treat optic glioma invariably results in GH deficiency within 2 years and that hGH therapy is required when GH deficiency is documented.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation therapy for gliomas of the optic nerve and chiasm

Thirty-three patients with optic glioma seen over a 30-year period were reviewed. Five patients (15%) had tumor confined to the optic nerve, 8 patients (24%) had optic nerve and chiasmal involvement, and the remaining 20 patients (61%) had invasion of contiguous structures as well as chiasmal involvement. Eleven patients (33%) had a history of neurofibromatosis. Two-thirds of the patients had either a biopsy or a partial resection of the tumor, with the remaining one-third being clinically diagnosed. All patients received irradiation to local fields. The median dose was 5040 cGy in 160 cGy fractions. Of patients alive at last follow-up, the median time of follow-up was 12.3 years. The 5-, 10-, and 15-year overall actuarial survivals were 94, 81, and 74%, respectively. Univariate and multivariate analysis were performed on the following clinical variables: extent of primary tumor, extent of surgery, dose of radiation, gender, race, age, and presence or absence of neurofibromatosis. Extension of the primary lesion to the optic chiasm and age less than or equal to 15 years were the only two variables to have statistically significantly inferior 15-year progression free survivals by multivariate analysis. Eighteen (55%) patients had treatment related complications with most involving the pituitary gland. We conclude that postoperative radiotherapy is beneficial in patients with chiasmal involvement and those with incomplete resections. A minimum tumor dose of 4000 cGy is recommended.

Temporal parameters of low energy laser irradiation for optimal delay of post-traumatic degeneration of rat optic nerve

Compression injury of a central nerve results in its degeneration with irreversible loss of function due to the inability of the mammalian central nervous system (CNS) to regenerate. In contrast, the CNS of lower vertebrates has a high capacity to regenerate. Recently, low energy laser irradiation was shown to attenuate degeneration in injured CNS nerves. The optic nerves of rats were subjected to moderate crush, calibrated so that some electrophysiological activity was preserved. The nerves were then subjected to low energy laser irradiation (10.5 mW, 2 min daily) for various periods. The electrical activity of the nerves, distal to the site of injury, was determined by measuring the compound action potential at the termination of the experiment. Two weeks of irradiation begun immediately after injury and continued daily thereafter, resulted in a compound action potential which was significantly higher (mean +/- S.E.M. 1856 +/- 535 microV) than that of non-irradiated injured nerves (351 +/- 120 microV). The effect was temporary and subsided within a week. This two-week irradiation was slightly more effective than a treatment lasting one week (1406 +/- 225 microV) and was significantly more effective than 4 days of irradiation (960 +/- 133 microV). The number of treatments is therefore important. The time at which the treatment commences relative to the injury is also critical. Irradiation initiated two hours after the crush was about half as effective as immediate irradiation (810 +/- 42 microV). No apparent effect was evident when the laser was applied for the first time 5 h, or longer, after the crush.(ABSTRACT TRUNCATED AT 250 WORDS)

Sarcoidosis of the anterior visual pathway: successes and failures

Four patients with progressive visual deterioration were found to have sarcoidosis involving the anterior visual pathway. They all developed chiasmal dysfunction and bilateral optic neuropathy, which responded to megadose corticosteroid therapy. When an attempt was made to withdraw the corticosteroids, the patients experienced a recrudescence of visual dysfunction and were subsequently unable to tolerate the corticosteroid dose levels necessary to maximise their visual potential. Each patient was treated with high-voltage radiation therapy, totalling up to 4500 rads. The beneficial response obtained was temporary, and immunosuppressive therapy with azathioprine or chlorambucil was instituted, preventing further deterioration.

The management of optic nerve sheath meningiomas

Thirty-eight patients (39 eyes) with optic nerve sheath meningiomas were entered into a treatment plan and were followed up for at least three years. Eighteen eyes were simply observed because they had minimal functional deficit or the eye was blind. Radiation was used on six eyes with documented progressive visual loss that still had useful vision. Surgery was initially used in an attempt to remove optic nerve sheath meningiomas but was abandoned except in exceptional cases. Total surgical removal of the tumor was carried out in ten eyes with loss of vision and in which the meningioma was growing. Surgery for subtotal or complete removal of the tumor followed by radiation was carried out in five eyes exhibiting aggressive growth of the tumor. This treatment plan has helped us to treat patients with optic nerve sheath meningiomas in an orderly way.

Unresectable gliomas in children: tumor-volume response to radiation therapy

Serial tumor volume measurements were performed on computed tomographic (CT) scans or magnetic resonance (MR) images of 12 children treated with radiation therapy for high-grade (three children) or low-grade (nine children) astrocytomas of the optic nerve, thalamus, hypothalamus, cerebellar-pontine angle, and pons. Three types of initial tumor response were observed: Tumor volume increased in four children, remained unchanged in one, and decreased immediately after completion of radiation therapy in the others. High-grade tumors regressed maximally within 6 months and low-grade tumors within 10-25 months. All high-grade tumors recurred within 12 months. Three low-grade tumors recurred 3, 6 1/2, and 10 years after diagnosis, respectively. The tumor-volume halving time was 60-78 days for high-grade tumors and 108-330 days for low-grade tumors. The tumor doubling time was 48-60 days for high-grade tumors. The posttreatment increase in tumor volume has implications for radiation treatment planning. It did not indicate a poor prognosis.

Treatment response in malignant optic glioma of adulthood

Two adults with malignant optic gliomas displayed dramatic tumor shrinkage and prolonged survival after radiation therapy alone in one case and combined radiation and chemotherapy in the other. Although malignant optic gliomas have been reported to be radiation resistant, marked treatment response may occur and aggressive treatment protocols should be considered.

Management of low-grade gliomas of the optic nerve and chiasm

Thirty-six patients were evaluated between 1965 and 1983 for glioma of the optic nerves and/or chiasm. Median follow-up was 10.2 years. Pathologic verification was obtained in 32 patients. Tumor initially confined to the optic nerve recurred in one of five patients after complete resection. The actuarial survival for 25 patients irradiated for biopsy-proven glioma of the optic chiasm was 96%, 90%, and 90% at 5, 10, and 15 years, respectively, and the progression-free survival was 87% at 5, 10, and 15 years. Vision stabilized or improved in 86% of patients after radiotherapy. Patients irradiated to a dose greater than a NSD of 1385 ret had a significantly improved progression-free survival (P = 0.015). One serious complication occurred after a dose of 1533 ret. The recommended radiation dose for optic glioma is 45 to 50 Gy with 1.8 Gy fractions.

Efficacy of radiotherapy in optic gliomas

Twenty-five children with optic gliomas were evaluated over a seven year period by sequential computed axial tomography in order to determine the efficacy of radiotherapy as a treatment modality. Indices of tumor progression or regression included both size and contrast enhancement characteristics. Twenty of 25 patients followed during this period received radiotherapy. Of these patients, ten had tumor regression, nine were stable, and one was worse. This result contrasts with five untreated patients, four of whom had tumor progression and one who was stable (x2 = 18.37, p less than .001). One of the children with tumor progression later received radiotherapy and demonstrated marked tumor regression. Of the 18 treated patients who could be tested reliably, visual function and/or regression occurred in seven children. None of the untreated patients improved. There were no definite complications of radiotherapy in this small group.

Optic nerve gliomas in children: a reappraisal

The Children's Tumour Registry in Manchester records details of children in the North West Region of England with gliomas of the anterior optic pathways. In the 30 years to 1983, the diagnosis of optic nerve glioma was confirmed in only 22 children out of a population of 1 million under the age of 15 years. This paper examines the presentation, investigation and management of these children in relation to the site of their tumour. The place of radiotherapy is considered, and with the widespread availability of new imaging techniques, fresh protocols are offered for the investigation and treatment of this rare tumour.

Optic neuropathy of Graves' disease. A report of a perimetric follow-up

Endocrine ophthalmopathy is one of the most common space occupying lesions of the orbit. The optic nerve can be involved to varying degrees in the disease. Marked optic neuropathy may be found in cases with normal visual acuity and normal optic nerve head. Perimetry is, therefore, recommended to diagnose or rule out a neuropathy. A case report will demonstrate that a quick screening perimetry with the Octopus program 07 allows a diagnosis and follow-up of the neuropathy. It is helpful in deciding on therapeutic measures and permits a safe monitoring of the therapeutic effect during the treatment period. The case further demonstrates a very quick recovery of the visual field following radiotherapy.

The moyamoya syndrome associated with irradiation of an optic glioma in children: report of two cases and review of the literature

We report two cases of the moyamoya syndrome which became clinically apparent after irradiation of an optic glioma during childhood. A summary of 14 cases of this syndrome following irradiation of intracranial tumors is also presented. Nine of these cases were optic gliomas; five were found in children with neurofibromatosis, another disorder that has a strong association with the moyamoya syndrome. The effectiveness of irradiation of optic gliomas in childhood is not definitely established. The possibility of inducing serious vascular disease is a further reason for caution when considering irradiating these tumors.

Occlusion of the internal carotid artery after radiation therapy for the chiasmal lesion

Occlusion of the intracranial portion of the internal carotid artery were encountered in two cases with suprasellar tumours, who had received irradiation therapy previously and shown excellent clinical improvement postoperatively. Clinical features and the angiographic characteristics were analysed in these two cases and the results were compared with reports in the literature. The occlusive effect of radiation on the arterial wall was conceived as the cause of carotid obstruction. In order to avoid this side effect of radiation therapy, especially for brain tumours of low malignancy in childhood, careful estimation of the radiation dose should be required and cerebral angiographic follow-up during and after the treatment with radiation is indicated, particularly when the patient develops cerebral transient ischaemic symptoms.

Radiation therapy for thyroid eye diseases

Sixty-two patients (28 men and 34 women, 26 to 84 years old) with thyroid ophthalmopathy were treated with approximately 20 Gy of fractionated photon irradiation. Eight of 14 patients with motility problems improved after treatment. Ten of 14 with thyroid optic neuropathy improved or stabilized, but four had recurrences within five months after completion of irradiation. Generally, patients who had disease durations of less than six months responded better than those with more long-term ocular changes.