Precision radiation therapy for optic nerve sheath meningiomas

Ophthalmic Ultrasound: A Diagnostic Atlas, 2nd Edition

BACKGROUND

Treatment of primary optic nerve sheath meningiomas (ONSMs) remains controversial. Although recent studies have suggested a favorable outcome of radiotherapy, controlled data on the efficacy of fractionated stereotactic conformal radiotherapy (SCRT) in primary ONSMs are still lacking.

METHODS

Seven eyes treated with SCRT (total dose: 54 Gy) were compared with six eyes that were not treated because of patient or physician preference. The indication for intervention was deterioration of visual function with or without imaging evidence of tumor progression. Patients with secondary ONSMs and those with neurofibromatosis type 2 were excluded. The mean follow-up period was 57 months for the treated eyes and 61 months for the untreated eyes.

RESULTS

Among the seven treated eyes, visual acuity improved in six, five of which sustained improvement of three or more Snellen lines. One eye deteriorated by two lines. Visual field improved in four eyes, remained stable in two, and deteriorated in one. Four untreated eyes showed worsening of visual acuity and two remained stable. Visual field deteriorated in three eyes and was stable in three. None of the untreated eyes experienced improvement in visual acuity or visual field. No complications of treatment were documented.

CONCLUSIONS

In agreement with previous reports, these results indicate that SCRT is superior to observation in its impact on visual function in eyes with primary ONSMs.

Optic nerve sheath meningioma: current diagnosis and treatment

✓Optic nerve sheath meningiomas (ONSMs) are rare tumors of the anterior visual pathway and constitute approximately 2% of all orbital tumors and 1–2% of all meningiomas. Untreated ONSMs almost always lead to progressive visual decline, color blindness, and finally complete loss of vision. Although resection is warranted in cases of widespread ONSM, surgery can lead to significant morbidity. Recently, stereotactic fractionated radiotherapy has shown effectiveness in improving or stabilizing remaining visual function with minimal procedural morbidity in patients with ONSM. The authors review the incidence, histopathological characteristics, clinical presentation, neuroimaging findings, and current treatment modalities for ONSMs, with an emphasis on fractionated stereotactic radiotherapy.

Primary optic nerve sheath meningioma: stereotactic fractionated radiation therapy as an emerging treatment of choice

BACKGROUND

Radiotherapy (RT) has occasionally been practiced in the treatment of optic nerve sheath meningioma (ONSM). Recently, stereotactic fractionated RT (SFRT) has been introduced as a tool with better precision for RT delivery. A comprehensive review was undertaken to provide more insight into this matter.

METHODS

A literature search was performed to identify reports dealing with both clinical aspects (diagnosis) and treatment in ONSM, focusing on RT in primary (p)ONSM. In particular, major emphasis was placed on the role of SFRT in pONSM.

RESULTS

SFRT was capable of achieving excellent local tumor control, with improved/stable functional capacity in > or = 80%, accompanied with very low toxicity in meticulously planned RT. This holds true for the majority of patients with progressive functional loss and probably the vast majority of those with some degree of functional loss at presentation. Those blind at presentation benefit from postoperative RT, whereas those with only minimal functional loss at presentation must be carefully selected for the best treatment, because a wait-and-see policy will inevitably lead to serious dysfunction or even blindness.

CONCLUSIONS

SFRT should be considered the treatment of choice for the majority of patients with pONSM. Every effort should be made to further investigate the remaining questions in this disease, such as optimal timing for the patients with no or slight vision loss at presentation.

The role of surgery in meningiomas involving the optic nerve sheath

OBJECTIVE

Clinical presentation, radiological appearance and treatment options of patients with optic nerve sheath meningiomas (ONSM) vary. To provide a baseline for treatment of this tumour entity a series of 24 patients with ONSM is presented.

METHOD

Clinical charts of the patients including surgical and histological records, imaging studies as well as meticulously focusing questionnaires of clinical outcome were reviewed.

RESULTS

Twenty four patients with ONSM were treated at the Neurosurgical Department from 1981 to 2002. Mean age at diagnosis was 44 years (14-69) with a female:male ratio of 7:1. The preoperative duration of symptoms was negatively correlated with the preoperative visual acuity. The microsurgical approach consisted of pterional craniotomy, intra-/extradural subtotal excision of the meningioma and bony decompression of the optic canal. Surgical results showed low surgical morbidity and preserved or even improved vision in 8/16 patients (50%) all of whom had rapid visual decline preoperatively. In the long-term, visual loss occur again occurred due to recurrence in about 20% of cases.

CONCLUSION

Microneurosurgery for treatment of ONSMs is still reserved for cases with intracranial extension, disfiguring proptosis and patients with rapid visual deterioration. Radiotherapy should be considered as treatment option in all other cases as it prolongs the time for functional vision in the affected eye with low morbidity.

Meningioma

Total excision is an appropriate treatment option for patients with benign meningiomas that are resectable with minimal morbidity. It is particularly appropriate for patients with significant mass effect causing symptoms. Fractionated conformal radiotherapy is an appropriate primary treatment option for patients with benign meningiomas of all sizes and all sites. It is particularly appropriate and preferred for optic nerve sheath meningiomas, for which there are few alternatives. Planned subtotal resection is appropriate if decompression is expected to relieve acute symptoms. After subtotal resection, it is appropriate to offer single-fraction radiosurgery or multifraction radiotherapy, depending on the size, location, and extent of residual tumor, so as to achieve progression-free survival and cause-specific survival rates comparable to those of other approaches.

The optic nerve: radiologic, clinical, and pathologic evaluation

The radiologic investigation of the optic nerve plays an integral part in the diagnostic evaluation of diverse lesions of the optic pathways including inflammatory diseases, vascular disorders and benign and malignant tumors and these radiologic modalities consist principally of CT and MR imaging and, in vascular lesions, MR angiography and conventional angiography. The selection of radiologic studies and their focus is based on the ophthalmologic examination where the ophthalmologist can often determine the suspected location of lesions in the anterior or posterior visual pathways. Furthermore, inspection of the eye, including adnexal structures and funduscopy, provides additional information in the clinical assessment of these patients. With technical advances in the last few years, CT and MR imaging can detect lesions and determine their location and extent with high sensitivity and specificity. This article discusses the radiologic, clinical, and pathologic evaluation of the optic nerve.

Primary radiotherapy for optic nerve sheath meningioma

Radiotherapy has recently been recognized as the treatment of choice for most primary optic nerve sheath meningiomas (ONSM). Radiotherapy is incorporated into the treatment of non optic nerve sheath meningiomas for unresectable or subtotally resected tumors. Most primary ONSM are not surgically approachable without a high risk of visual deterioration. Radiotherapy has been found to prevent or delay tumor growth for the majority of patients and improve vision in some. We review the rational and current methods of the use of radiotherapy for these tumors.

Preliminary visual outcomes after three-dimensional conformal radiation therapy for optic nerve sheath meningioma

PURPOSE

We assessed visual outcomes, local control, and toxicity associated with three-dimensional conformal radiation therapy (3D-CRT) for primary optic nerve sheath meningiomas (ONSM).

METHODS

Twenty-three patients diagnosed with ONSM were evaluated at the University of Michigan between 1986 and 2001. Fourteen patients were treated with 3D-CRT. Detailed pre- and postradiation treatment ophthalmologic examinations and MRIs were performed on all patients. Clinically significant visual acuity change was defined as a >or=three line change on the Snellen chart. Mean deviation change of >or=three decibels was defined as a clinically significant visual field change. Radiographic progression was defined as any increase in size on MRI. Acute and late toxicity was scored according to RTOG criteria.

RESULTS

Median follow-up was 51.3 months. Five patients had a clinically significant improvement in visual acuity. Seven had stable acuity, and only 2 worsened. Nine patients had clinically significant visual field improvement. One patient developed early radiation retinopathy, 1 experienced orbital pain, 1 developed dry eye, and 2 developed iritis. No patient has required additional treatment, and none have demonstrated radiographic progression.

CONCLUSION

3D-CRT is effective in controlling tumor growth while improving or preserving vision in most patients with optic nerve sheath meningiomas.

Update on treatment modalities for optic nerve sheath meningiomas

Optic nerve sheath meningiomas (ONSMs) represent 1 to 2% of all meningiomas and one third of all optic nerve tumors. The management of ONSMs is controversial. Traditional surgical removal often results in postoperative blindness in the affected eye and thus has been abandoned as a treatment option in most patients. Surgery may be unnecessarily aggressive, especially if the patient has useful vision. When these tumors are left untreated, however, ensuing progressive visual impairment may lead to complete blindness. More recently, radiotherapy has gained wider acceptance as a treatment for these lesions. The authors of some reports have suggested that fractionated stereotactic radiosurgery (SRS) may be the best option for treating primary ONSMs. In patients with documented progressive visual deterioration, fractionated SRS may be effective in improving or stabilizing remaining functional vision. The authors review the clinical presentation, radiographic characteristics, and management of ONSMs, emphasizing the use of fractionated SRS.

Stereotactic fractionated radiotherapy in patients with optic nerve sheath meningioma

PURPOSE

To evaluate the effectiveness of stereotactic fractionated radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). METHODS AND MARERIALS: Between 1994 and 2000, a total of 39 patients with either primary (n = 15) or secondary (n = 24) ONSM were treated with SFRT and received a median total tumor dose of 54 Gy using 1.8 Gy/fraction.

RESULTS

The radiographic response to SFRT was documented in all patients as stable disease (no change) except for 1 patient with a partial response. After a median follow-up of 35.5 months, all patients with ONSM were alive without recurrence. The visual fields and visual acuity were improved in 6 of 15 and 1 of 16 examined eyes in patients with primary ONSM, respectively, and in 6 of 24 and 7 of 26 examined eyes in patients with secondary ONSM, respectively. Stable visual fields and visual acuity was observed in 8 of 14 and 15 of 16 patients with primary ONSM, respectively, and in 17 of 24 and 19 of 26 patients with secondary ONSM, respectively. Except for reversible alopecia and erythema, no other SFRT-related toxicity was observed.

CONCLUSION

SFRT represents a very effective and low-toxic treatment modality for ONSM. Despite a median follow-up of 3 years, this series of primary ONSM holds promise for future studies. It adds substantial evidence that SFRT may definitely become a standard treatment approach in selected cases of ONSM.

Stereotactic fractionated irradiation of optic nerve sheath meningioma: a new treatment alternative

BACKGROUND

Primary optic nerve sheath meningioma (ONSM) is a rare but almost invariably blinding tumour when its natural history is observed in a "wait and see" strategy. Surgery has hitherto only been advocated in case of progressive disease involving intracranial structures, as it leads to iatrogenic blindness in the overwhelming majority of cases. Therefore, treatment options bearing lesser risk of functional deterioration are highly desirable, both in cases of intracranial involvement as well as during earlier phases of the disease which are currently generally left untreated. The authors report the outcome of the largest series of patients to date treated by stereotactic fractionated irradiation as a new treatment approach in ONSM at all stages.

METHODS

15 patients (16 nerves) underwent stereotactic fractionated conformal irradiation with a total dose of 54 Gy, using standard fractionation. Main outcome parameters included visual acuity and visual field, as well as three dimensional remission as documented by imaging.

RESULTS

Tumour control was confirmed in all 15 patients undergoing stereotactic fractionated conformal irradiation (mean follow up 37 (range 12-71) months). No patient developed functional deterioration during or after treatment. Moreover, visual acuity improved by more than two lines in one patient and the visual field improved in six cases. Visual outcome in the other patients remained unchanged. There were no significant side effects of radiation therapy.

CONCLUSION

These data provide convincing evidence that stereotactic fractionated conformal irradiation is an effective treatment option for primary ONSM with minimal treatment related morbidity. It should therefore be considered as therapeutic option both in early stage ONSM where surgery cannot be justified as well as in later stages, where surgery is so far considered the first line approach.

Fractionated stereotactic radiotherapy for the treatment of optic nerve sheath meningiomas: preliminary observations of 33 optic nerves in 30 patients with historical comparison to observation with or without prior surgery

OBJECTIVE

We investigated the safety and efficacy of stereotactic radiotherapy as an alternative therapy to surgical resection for optic nerve sheath meningiomas (ONSMs).

METHODS

Thirty patients and 33 optic nerves with ONSMs were treated with conventional fractionated stereotactic radiotherapy treatment (CF-SRT) between July 1996 and May 2001 with the use of a 6-MeV LINAC designed for and dedicated to radiosurgery. The LINAC technique involved daily CF-SRT involving a relocatable frame, an average of three isocenters, and high-radiation dose conformality established by noncoplanar arc beam shaping and differential beam weighting. The patients who were treated with CF-SRT were followed clinically with serial visual fields and radiographically with both magnetic resonance imaging and functional (111)In-octreotide single-photon emission computed tomography. The results of treatment were compared with a historical control group of ONSM patients who were either observed or treated surgically and then observed.

RESULTS

Our study population comprised 18 women and 12 men with a median age of 44 years (age range, 20-76 yr). The median isosurface radiation dose was 51 Gy (dose range, 50-54.0 Gy), and the median clinical follow-up time was 89 weeks (range, 9-284 wk). Of 22 optic nerves with vision before CF-SRT, 20 nerves (92%) demonstrated preserved vision, and 42% manifested improvement in visual acuity and/or visual field at follow-up. Comparison of our patients with a historical control group revealed preserved vision in only 16% of patients in a comparable period of observation, along with a 150% greater probability of visual improvement. Four patients (13%) had posttreatment morbidities, including visual loss (two patients), optic neuritis (one patient), and transient orbital pain (one patient). On magnetic resonance imaging studies, there was no evidence of tumor progression or recurrence in all patients, including tumor volume reductions noted in four patients. All six patients monitored with (111)In-octreotide scintigraphy demonstrated significant decreases in tumor activity after CF-SRT.

CONCLUSION

To date, this article describes the largest reported series of ONSMs. Although longer follow-up is necessary, we think that CF-SRT represents a safe alternative to surgery and offers a higher likelihood of preserved or improved vision in patients with ONSM. Our analysis suggests that CF-SRT is also preferable to observation. Functional (111)In-octreotide single-photon emission computed tomographic scintigraphy provides a useful technique for the assessment of tumor control that complements serial posttreatment magnetic resonance imaging in patients with ONSMs.

Optic nerve sheath meningiomas: visual improvement after stereotactic radiotherapy

OBJECTIVE

The management of primary optic nerve sheath meningioma (ONSM) is controversial. Surgery often results in postoperative blindness in the affected eye and thus has been abandoned as a treatment option for most patients. When these tumors are left untreated, however, progressive visual impairment ensues, which also leads to blindness. Recently, radiation therapy has gained wider acceptance in the treatment of these lesions. Experience with stereotactic radiotherapy (SRT) in the treatment of ONSMs is limited because of the rare incidence of this tumor. We present a series of patients with ONSM who were treated with SRT.

METHODS

Five patients (three women, two men), ranging in age from 40 to 73 years, presented with progressive visual loss with decreased visual field, visual acuity, and color vision affecting six eyes (one patient had tumor involving both optic nerves). One patient also presented with proptosis and diplopia. Five eyes had functional residual vision (range, 20/20 to 20/40), and one eye was completely blind. All five patients were diagnosed clinically and radiographically to have an ONSM. Three were intraorbital, one was intracanalicular as well as intraorbital, and one was a left ONSM extending through the optic foramen into the intracranial space and involving the right optic nerve. The five functional eyes were treated with SRT by use of 1.8-Gy fractions to a cumulative dose of 45 to 54 Gy.

RESULTS

Follow-up ranged from 1 to 7 years, and serial magnetic resonance imaging revealed no changes in the size of the tumor in all five patients. Four patients experienced dramatic improvement in visual acuity, visual field, and color vision within 3 months after SRT. One patient remained stable without evidence of visual deterioration or disease progression. None had radiation-induced optic neuropathy.

CONCLUSION

SRT may be a viable option for treatment of primary ONSM in patients with documented progressive visual deterioration, and it may be effective in improving or stabilizing remaining functional vision.

A long-term visual outcome comparison in patients with optic nerve sheath meningioma managed with observation, surgery, radiotherapy, or surgery and radiotherapy

PURPOSE

Comparison of treatment outcome in patients with primary optic nerve sheath meningioma (ONSM).

DESIGN

Retrospective, nonrandomized, comparative interventional case series.

PARTICIPANTS

Sixty-four patients with at least 50 months of well-documented follow-up.

INTERVENTION

Observation, surgery only, radiotherapy only, or surgery and radiotherapy.

MAIN OUTCOME MEASURES

Visual acuity expressed as ratio, radiographic progression, and treatment complications.

RESULTS

Sixty-four patients (55 women [85.9%] and nine men [14.1%]) were followed for a mean of 150.2 months (range, 51-516 months; standard deviation [SD], 74.7). The mean age at diagnosis was 47.1 years (range, 17-81 years; SD, 15.4). Fifty-eight patients had unilateral disease and six patients had bilateral disease. Of 59 patients with vision greater than no light perception at diagnosis, 13 patients were observed only, 12 had surgery only (four biopsies or partial resections, eight total resections), 18 received radiation alone, and 16 had surgery and radiation (14 biopsies or partial resections and radiation, two total resections and radiation). Irradiated patients received 4000 to 5500 cGy of conventional multiport or conformal external beam therapy, typically fractionated over 6 weeks. Visual acuity measurements at diagnosis among the four groups were not different (ratio, P = 0.186). Visual acuity at diagnosis was > or =0.5 in 56.3%, 0.4 to 0.050 in 12.5%, and <0.050 in 31.3%. Visual acuity measures at last follow-up were different among the four groups (ratio, P = 0.004). At last follow-up the acuity was > or =0.5 in 28.1%, 0.4 to 0.050 in 15.6%, and <0.050 in 56.3%. Visual acuity fell significantly for the observed only (ratio, P = 0.002), surgery only (ratio, P = 0.019), and surgery with radiation groups (ratio, P = 0.030). The radiation only group showed a decrease in visual acuity that was not significant (ratio, P = 0.301). Complication rate was 33.3% in radiation only cases, 66.7% in surgery only cases, and 62.5% in surgery with radiation cases. Twenty-one patients (32.8%) showed radiographic progression. Four patients who were observed, seven patients who had surgery alone, and eight patients who had surgery and radiation developed radiographic progression. Two patients who had radiation alone had radiographic progression before treatment. Only two patients treated with radiation only showed radiographic progression after radiotherapy, and both had at least one surgical procedure before the radiotherapy.

CONCLUSIONS

Patients with ONSM receiving radiation alone demonstrated the best visual outcome during the follow-up period. We recommend that fractionated external beam radiation (5000-5500 cGy) be considered as initial treatment in adults in selected cases of ONSM when preservation of visual function is a reasonable therapeutic goal.

Intensity modulated conformal therapy for intracranial lesions

The Peacock planning and delivery system was used to create treatment plans and deliver these plans to patients. The system involves an arc therapy delivery of small (2 cm long) slices of radiation combined with indexing of the couch to achieve target coverage. Two clinical examples are shown to demonstrate the system's capability and evaluate the resources required to produce and deliver the plans. One plan is an optic sheath meningioma and the other is a craniopharyngioma that surrounded the optic chiasm. The optic sheath meningioma was treated to 50 Gy in 25 fractions. The treatment involved delivery of two arcs. The total time to set up the patient and deliver the treatment was less than 15 min. Planning and plan validation after computed tomography required approximately 3 days. The patient had 100% restoration of her field of vision and is stable 3 years post therapy. The second patient is a 9-year-old who had a craniopharyngioma which surrounded the optic chiasm. The tumor was treated to 50.4 Gy in 28 fractions and the dose to the optic chiasm was limited to 45 Gy. The treatment required three arcs and total treatment time was less than 20 min. The patient is stable 15 months post therapy. The system is able to create and deliver radiation patterns that are unique. These plans can be created and delivered in times that rival conventional forward planning conformal radiotherapy systems that cannot produce or conveniently deliver such plans.

Target volumes in radiotherapy for high-grade malignant glioma of the brain

Delineation of the clinical target volume (CTV) in radiation treatment planning of high-grade glioma is a controversial issue. The use of computerized tomography (CT) and magnetic resonance imaging (MRI) has greatly improved the accuracy of tumor localization in three-dimensional planning. This review aims at critically analyzing available literature data in which tumor extent of high-grade glioma has been assessed using CT and/or MRI and relating this to postmortem observations. Attention is given to the pattern of tumor spread at initial presentation and to tumor recurrence pattern after external beam irradiation. Special emphasis is given to the site of tumor regrowth after radiation treatment in relation to the boundaries of the CTV. Guidelines for delineating CTV will be inferred from this information, taking data on radiation effects on the normal brain into account.

Optimizing radiotherapy of orbital and paraorbital tumors: intensity-modulated X-ray beams vs. intensity-modulated proton beams

PURPOSE

This study presents a dosimetric optimization effort aiming to compare intensity-modulated (IM) X-rays and IM protons in 4 different orbital and paraorbital tumors. These are most challenging targets for standard radiotherapy due to their close relationship with the eyes and related structures.

METHODS AND MATERIALS

A primary orbital lymphoma, an optic nerve meningioma, a sphenoidal ridge meningioma protruding into the orbit, and a pediatric parameningeal paraorbital rhabdomyosarcoma were selected for the purpose of this study. Planning target volumes (PTVs) and organs at risk (OAR) were defined in each patient CT data set for each tumor site. IM X-ray and IM proton three-dimensional treatment plans were implemented. The following total tumor doses were prescribed: 30 Gy for the orbital lymphoma, 54 Gy for both meningiomas, and 50.4 Gy for the rhabdomyosarcoma case. Dose-volume histograms (DVHs) were obtained for all targets and OAR with both treatment techniques. DVHs were used to predict normal tissue complication probabilities (NTCPs) for the OAR in the vicinity of the tumor.

RESULTS

The PTV coverage was optimal and equally homogeneous with both IM X-rays and IM proton plans in the 4 tumor sites. DVHs for most OAR were better with IM proton beams especially in the low- to mid-dose range region. The integral nontarget dose was lower with IM protons in every case (factor ranging from 1.5 to 1.9). However, predicted NTCPs (for severe late effects) were equally low for both treatment techniques in every tumor site.

CONCLUSION

Although IM proton plans optimally decreased the dose to the OAR in all tumor sites, both optimized X-ray and proton beams equally succeeded to reduce severe-toxicity prediction risks to less than 5% while optimally treating the PTV.

A new approach to an old problem

A patient with progressive visual loss was found to have an optic nerve sheath meningioma. The patient was treated with stereotactic radiotherapy, a computer-guided stereotactic technique that minimizes the risk of radiation-induced optic neuropathy. Six months after treatment, the patient was doing well and showed no signs of radiation-induced optic neuropathy.

Radiotherapy of primary malignant brain tumors

Radiotherapy is usually recommended for patients with a primary malignant brain tumor. The foundation for its use is grounded on the results of randomized trials for malignant gliomas which have demonstrated a relationship between survival and external beam radiation dose. Although similar trials have not been performed for most other primary intracranial tumors, radiation oncologists treat them in a similar fashion, delivering the highest possible dose consistent with acceptable levels of normal tissue damage. In most cases, focal therapy is required, using modern three-dimensional treatment planning and delivery--with whole brain or craniospinal therapy used only for infrequently encountered clinical presentations. With modern planning, the volume of normal tissue subjected to possible radiation damage can be minimized. Radiation effects in normal tissues typically occur months to years after treatment.

Big muscles and big nerves

For 11 years, a 50-year-old woman with euthyroid Graves' disease experienced intermittent exacerbations of her orbitopathy associated with a decline in visual acuity. On each occasion, treatment with systemic corticosteroids led to prompt recovery of vision. Upon referral for consideration for orbital decompressive surgery, computed tomography and magnetic resonance imaging scanning detected bilateral optic-nerve sheath meningiomas, as well as typical findings of Graves' disease. Orbital radiation therapy led to stabilization of visual function and orbital findings, eliminating the need for systemic steroids. To our knowledge, this is the first reported case of Graves' disease associated with bilateral optic nerve sheath meningiomas.

Management of orbital tumors

Orbital tumors are uncommon. In children, both malignant and benign causes of orbital proptosis necessitate urgent assessment; in many cases, emergent intervention is necessary to avoid blindness. In adults, proptosis is most commonly associated with thyroid orbitopathy. Orbital tumors in adults rarely are characterized by the explosive growth and damage that can occur with childhood lesions. In both age-groups, the evolution of better scanning modalities, such as magnetic resonance imaging with fat saturation and gadolinium enhancement, has improved diagnostic accuracy, especially in patients with loss of vision. In more than 95% of cases, noninvasive techniques yield a correct diagnosis. In patients who require nonsurgical intervention, especially if the diagnosis is uncertain, fine-needle aspiration biopsy has an accuracy that exceeds 95%. Combined-modality therapy has improved the control of and decreased the morbidity associated with several orbital tumors. Surgical advances, such as the ancillary use of the CO2 laser, have enhanced the management of some orbital tumors.