Optic Nerve Sheath Meningioma Research Articles

Orbital Lesions: A bird's eye view of series of 2068 cases in 27 years in a tertiary care hospital in Pakistan.

To determine the relative frequency of orbital lesions based on the site of origin and histopathology at a Tertiary care hospital (Mayo Hospital, Lahore Pakistan) from 1996 till 2022 (27 years). This descriptive case series included 2651 patients of all age groups presenting with orbital lesions who initially got enrolled at Institute of Ophthalmology Mayo Hospital, Lahore from 1996 till 2022. Of these, 583 patients left against medical advice. So, clinical data of 2068 patients were completely analyzed. Lesions were managed medically and/ or surgically. Final clinical diagnosis, with the help of histopathology, was used to classify the lesions. There were 1258 (60.9%) adults and 810 (39.1%) children, 1358 (65.66%) were neoplastic while 710 (34.33%) non-neoplastic lesions. Amongst the neoplastic lesions, 405 (29.8 %) were benign and 953 (70.2%) malignant. Primary orbital lesions were 1676 (81.04%), Secondary orbital lesions were 300 (14.51%), Endocrine/ hematopoietic reticulo-endothelial system lesions were 84 (4.06%) and Metastatic lesions from distant organs were 08 (0.39%). Retinoblastoma, rhabdomyosarcoma, optic nerve gliomata were common in children. Pleomorphic adenoma & adenocystic carcinoma of lacrimal gland, cavernous hemangioma, optic nerve meningioma, neurofibroma, schwannoma, squamous cell carcinoma of eyelid, carcinoma of maxillary antrum and lymphomas were more common in adults.

Optic Nerve Amyloid Deposition Disguised as Optic Nerve Sheath Meningioma.

Localized orbital amyloidosis is a rare clinical entity. Periocular and orbital amyloid deposits are mainly located at the lacrimal apparatus, eyelid, conjunctiva, ocular adnexa, extraocular muscles, and levator palpebrae muscle. In this article, we report an unusual case of optic nerve amyloid deposition in an 82-year-old African American woman who presented with vertical diplopia. MRI revealed an enhancing mass from the optic nerve sheath, and CT showed foci of calcifications suggestive of optic nerve meningioma. However, an incisional biopsy demonstrated lymphoproliferative disease with focal optic nerve sheath amyloid deposition confirmed by histologic Congo red staining and immunohistochemistry.

ETMR-04. OPTIC NERVE SHEATH MENINGIOMAS IN CHILDREN-DIAGNOSTIC AND THERAPEUTIC CHALLENGES BASED ON A CASE SERIES

Abstract BACKGROUND Optic nerve sheath meningiomas (ONSM) are rare, comprising 1-2% of paediatric CNS meningiomas. Despite slow growth, ONSM often lead to vision loss in the affected eye. Diagnosis is challenging due to the tumour’s proximity to the optic nerve, complicating biopsy or complete removal. METHODS We searched our Neuro-Oncology MDT database for patients treated for ONSM between Jan 2018 and Dec 2023. We retrospectively reviewed clinical presentation and diagnostic workup that led to the diagnosis of ONSM. RESULTS 6 children aged 3-15years (mean 9 years) were identified over 5 years. 3 children were treated at GOSH, 2 at UCLH and 1 at BCH. 3/6 patients were male. 2/6 underwent a biopsy. Presenting symptoms included headache, acute visual loss and eye pain. 2/6 patients presented with bilateral vision deterioration. The average time between onset of symptoms and presentation was 8 months (range 3–15 months). Identified causes of delayed diagnosis included delayed presentation related to COVID-19 pandemic (2 patients) and impaired quality of imaging due to dental braces (1 patient). Whilst awaiting diagnosis, 2 patients lost vision completely in their affected eye. Diagnostic workup included: optic disc examination (6 patients), lumbar puncture (2 patients), angiotensin-converting enzyme (sACE) (2 patients), MRI brain and spine (6 patients), CT scan (6 patients), PET-DOTATE scan (3 patients), NF2 genetic testing (4 patients). Two patients completed PBT therapy while 1 is undergoing radiotherapy. One patient underwent an enucleation, while the rest are under surveillance. CONCLUSIONS Paediatric ONSM diagnosis remains challenging despite advanced imaging. Our review highlights the added value of CT and PET-DOTATATE when a biopsy is high-risk. CT reveals calcification in 20-50% ONSM while the role of PET-DOTATATE is related to the expression of somatostatin receptor 2 in meningiomas. Despite optimal treatment, vision loss maybe unavoidable. Early multidisciplinary consultations are advised for enhanced outcomes.

Treatment of Meningiomas Involving the Optic Canal with Endoscopic Transnasal Decompression of the Optic Nerve

Management of patients with optic nerve sheath meningiomas (ONSMs) is controversial and the treatment strategy in this patient group is still up for discussion. Transnasal endoscopic orbital and optic nerve decompression aims to reduce the pressure in the orbit and on the optic nerve and thereby prevent vision loss. This article presents material from 7 cases of transnasal endoscopic orbital decompression. The study design is a retrospective cohort study. The aim was to include all patients with a meningioma residing along the nerve sheath and who were operated using endoscopic transnasal decompression of the orbit and if needed the optic canal at Odense University Hospital. Data from the medical records were collected and pre- and postoperative eye examinations were compared. In addition, it was recorded whether there were complications to the procedure and whether additional treatments were given. In total, 4 women and 3 men were included in the study. Four out of 7 patients experienced improvement in vision after the operation. One patient experienced unchanged vision and 2 patients experienced deterioration of vision after surgery. The current report of 7 patients with ONSM shows promising results for this surgical procedure as 4 out of 7 patients experienced improvement in their vision at follow-up examinations. The 2 patients who experienced deterioration of vision already had severely reduced vision preoperatively, which indicates that surgery should be considered before the vision becomes significantly reduced.

Development of Magnetic Resonance-Compatible Head Immobilization Device and Initial Experience of Magnetic Resonance-Guided Radiation Therapy for Central Nervous System Tumors

PurposeWe aimed to develop and investigate positional reproducibility using a fixation device (Unity Brain Tumor Immobilization Device, UBID) in brain tumor patients undergoing magnetic resonance (MR)-guided radiotherapy (RT) with a 1.5 Tesla (T) MR-linear accelerator (LINAC) to evaluate its feasibility in clinical practice and report representative cases of central nervous system (CNS) tumor patients. Materials and MethodsQuantitative analysis was performed by comparing images obtained by placing only the MR phantom on the couch with those obtained by placing UBID next to the MR phantom. Twenty patients who underwent RT for CNS tumors using 1.5T MR-LINAC between June 2022 and October 2022 were retrospectively analyzed. Among them, five did not use UBID, whereas 15 used UBID. The positional reproducibility of UBID was evaluated using the median interfractional and intrafractional errors in the first 10 fractions. ResultsEach MR quality factor of the MR phantom with UBID satisfied the criteria presented by Elekta. Median values of median shifts in the mediolateral, anteroposterior, and craniocaudal axes for interfractional errors were 2.98-mm, 2.35-mm, and 1.40-mm, respectively. For intrafractional errors, the median values were 0.05-mm, 0.03-mm, and 0.06-mm, respectively. The median values of the median rotations in pitch, roll, and yaw for both interfractional and intrafractional rotations were 0.00°. One patient diagnosed with an optic nerve sheath meningioma received RT with motion monitoring during irradiation. In two patients, changes in the tumor cavity and residual lesions were observed in the MR images obtained using 1.5T MR-LINAC on the day of the first treatment and immediately before the 21st fraction, respectively; therefore, offline/online adaptation was performed. ConclusionThe reproducible and immobile UBID is clinically feasible in patients with CNS tumors receiving RT with 1.5T MR-LINAC. Based on our initial experience, we developed a workflow for 1.5T MR-LINAC treatment of CNS tumors.

Tumors of the third ventricle in children (literature review).

Tumors of the third ventricle are rare and account for 0.6–0.9 % of all pediatric brain tumors. Tumors of the third ventricle are divided into primary tumors, such as choroid plexus papillomas and ependymomas, and secondary tumors, such as craniopharyngiomas, optic nerve gliomas, pineal tumors, and meningiomas. Choroid papilloma is a common tumor, the treatment of which is mainly based on microsurgical resection. Apart from the many treatment options for craniopharyngiomas, microsurgery is the preferred treatment option. Ependymomas also have several treatment options, with microsurgical removal considered the first line of treatment.

Gross-total resection in optic nerve sheath meningiomas: minimally invasive and cosmetic pleasing

PurposeThe optic nerve sheath meningioma (ONSM) is one of the most challenging tumors in orbital surgery. From the perspective of mental health and patient needs, we analyzed the necessity and importance of the endoscopic transnasal approach (ETA) combined with optic nerve transection (ONT) in gross-total resection (GTR) in ONSM patients with residual vision and aim to broaden the use of ONT for specific people.MethodsThe authors included patients with ONSMs who were treated between 2014 and 2022. We divided those cases into two groups named ETA group and lateral orbitotomy approach (LOA) group. We present the application of ETA and analyze the preoperative indication of the ONT and compared the advantages and disadvantages between ETA and LOA. The degree of tumor resection was based on imaging and surgical evaluation.ResultsA total of 23 patients with ONSM were included. Sixteen patients underwent ETA, and seven underwent LOA. Among ETA cases, GTR was achieved in 14 patients with ONT and most patients maintained normal eye movement function (75%) and morphology (93.75%). In the ETA group, 14 patients experienced vision loss, while two other patients saw improvements in vision. And proptosis was alleviated (5.20 ± 2.34 vs 0.27 ± 0.46, p < 0.0001). Six patients with blindness and proptosis of the LOA group resulted in GTR with ONT and ophthalmectomy. Although intracranial extension and recurrence included no cases in the two groups, a significant psychological gap was presented due to cosmetic problems.ConclusionsUnder the premise of reducing damage and improving aesthetics, the selection of ETA combined with ONT to gross-total resect ONSMs successfully provides a minimally invasive access with acceptable complications. As an important adjunct to GTR in the surgical treatment of ONSM, the scope of ONT application should be expanded to relieve the patient’s psychological burden.

Radiation therapy for optic nerve sheath meningiomas: Local control and treatment related visual changes

ObjectiveOur primary objective is to evaluate the local control of optic nerve sheath meningiomas (ONSMs) treated with ionizing radiation and related visual changes after treatment. Our secondary objective is to describe the clinical characteristics and perform an analysis of the treatment impact on the functional status of this group of patients. MethodsWe present our series of 19 patients treated with ionizing radiation therapy at our radio-neurosurgery unit between 2016 and 2022. The setting, ophthalmological follow-up, morbidity, and survival are analyzed and discussed. ResultsPatients were followed up, and the impact of treatment on local disease control, visual alterations of the affected eye, and functional status of the patient were analyzed. The progression-free survival (PFS) median was 60 months (95% CI 50.3–69.6 months). The estimated PFS rates at 48 and 66 months were 100% and 66%, respectively. At diagnosis, nine (47.3%) eyes were in amaurosis and ten (52.6%) with vision. Of the ten patients without amaurosis at the time of diagnosis, three (30%) maintained unchanged visual acuity, and seven (70%) had decreased visual acuity; three of them developed amaurosis during the first year after treatment (p = 0.018). ConclusionsUsing ionizing radiation therapy is a successful treatment for the local control of ONSMs. This therapeutic modality can compromise the visual acuity of the affected eye and improve dyschromatopsia and campimetry defects. The life prognosis is good for these patients, with a zero mortality rate, but their vision prognosis is poor.

Detection of Optic Nerve Sheath Meningioma Using Computed Tomography Somatostatin Receptor Scintigraphy: A Case Report

Optic nerve sheath meningiomas (ONSM) pose diagnostic challenges due to their rarity and imaging overlap with other optic pathway lesions. This case study presents a patient initially exhibiting decreased visual acuity, where conventional MRI failed to conclusively diagnose the underlying pathology. Employing Tektrotyd-Tc99m tomography, a novel imaging modality utilizing somatostatin analog radiotracers, enabled precise localization and characterization of the ONSM. This study underscores the importance of leveraging advanced imaging techniques in the comprehensive management of optic nerve sheath meningiomas.

Optic nerve meningioma and cloacal adenocarcinoma in a Humboldt penguin.

A 26-y-old, male, captive Humboldt penguin (Spheniscus humboldti) was euthanized following a 3.5-mo history of weakened elimination mechanics, recurrent tenesmus, intermittent hemorrhagic droppings, and a cloacal mass. Blepharospasm, of unknown cause, of the right eye was present for ~3 mo before euthanasia. Autopsy revealed a cloacal adenocarcinoma with localized coelomic carcinomatosis and distant metastases to the liver and lungs. On histopathology, a 2.6 × 1.2 × 0.5-mm, well-demarcated mass was found surrounding the right optic nerve, expanding the subdural space and wrapping the leptomeninges. The mass was composed of neoplastic spindle-to-polygonal cells consistent with a meningioma, meningothelial subtype. No evidence of neoplasia was found in the optic chiasm or brain, indicating a primary retrobulbar meningioma. Immunohistochemistry for cytokeratin AE1/AE3, vimentin, and S100 revealed robust and consistent immunoreactivity to vimentin, and weak and variable immunoreactivity to cytokeratin and S100, supporting the diagnosis. Meningiomas have been described only rarely in avian species, and we found no reports of optic nerve meningiomas in any avian species to date. The optic nerve meningioma in this case was considered a clinically incidental finding.

Orbital tumors

Orbital tumours include a variety of orbital diseases of different origins. In the case of malignant orbital tumours, early detection is important so that treatment can be initiated promptly. Neuroradiological imaging, in particular magnetic resonance imaging (MRI), plays an important role in the diagnostic of orbital tumours. In adults, lymphoproliferative diseases, inflammations and secondary orbital tumours are most frequently found, whereas in children mostly dermoid cysts, optic gliomas and capillary haemangiomas are found. Optic glioma is a pilocytic astrocytoma and accounts for two thirds of all primary optic tumours. Optic nerve sheath meningiomas mostly affect middle-aged women. In childhood, retinoblastoma is the most common intraocular tumour. This is an aggressive malignant tumour which can occur unilaterally or bilaterally. Based on the imaging findings, differential diagnoses can usually be easily narrowed down using criteria such as age of manifestation, frequency, localisation and imaging characteristics.

Analysis of safety and efficacy of proton radiotherapy for optic nerve sheath meningioma.

Primary optic nerve sheath meningiomas (ONSMs) represent a group of benign tumors originating from the optic nerve sheath, typically causing painless, gradual onset monocular visual loss, which can result in blindness if left untreated. Radiation therapy represents an important treatment option for patients with ONSM, allowing for preservation and potential improvement in visual function. In particular, proton radiotherapy may enable a reduction of the side effects due to its physical advantage of an inverted dose profile with a steep dose gradient. The study investigates the visual acuity, local tumor control, and treatment-related toxicities following proton beam radiotherapy with a single institutional cohort comprising 32 patients treated for ONSM. Patients with primary ONSM, either histologically (16/32) or radiologically confirmed (16/32), which were treated at the Department of Radiation Oncology at the University Hospital Heidelberg (Germany) were assessed in regard to their visual outcomes, treatment toxicity, and local tumor control following radiotherapy according to response assessment in neuro-oncology criteria. After a median follow-up time of 39.5 months, the 5-year local progression-free survival was estimated at 100%, with 84.4% of patients reporting improvement or stability in visual acuity during their last follow-up. Radiation-induced optic neuropathy (RION) was encountered in 9.4%. Our study demonstrates proton beam therapy as a safe and effective treatment alternative in the therapeutic management of ONSMs. RION represents a rare but dreaded complication after treatment. Future head-to-head comparisons with photon radiotherapy in a prospective setting are required to demonstrate a potential, additional clinical benefit.

Optic Nerve Sheath Meningiomas: A National Surveillance, Epidemiology, and End Results (SEER) Database Analysis.

Optic nerve sheath meningioma (ONSM) is a rare optic nerve cancer with considerable morbidity. This national analysis validates previously known ONSM concepts while providing insight into novel risk factors. The Surveillance, Epidemiology, and End Results (SEER) Program was queried from 2000 to 2019 for all histologic subtypes of meningioma primary to the optic nerve. Relevant clinical and demographic variables were analyzed. Asymptotic one-sample test for binomial proportions and Cox proportional hazards modeling evaluated the significance of factor associations. A total of 51 ONSM cases were extracted. A greater proportion of cases were observed in females (N = 37, 73% , P < 0.001) and individuals with age 50 years or more (N = 29, 57% , P < 0.001); the mean number of months from diagnosis to treatment was 4.6 months (SD 4.1, range 13). Psychosocial epidemiologic parameter analysis demonstrated a greater proportion of patients with married status on diagnosis (N = 31, 61% , P < 0.001), listed total family income between $55,000 and $74,999 (N = 24, 47% , P < 0.001). Relative to cases diagnosed clinically only, cases diagnosed radiologically without microscopic confirmation experienced decreased all-cause mortality (HR = 0.041, P = 0.050). Our SEER national analysis affirms previously characterized ONSM concepts. Upon ONSM diagnosis and if needed, treatment protocols are not significantly delayed. Novel psychosocial factors for ONSM were identified, including marital status, total family income, and non-Hispanic white race. Additional ONSM diagnostics may reduce longitudinal mortality burden.

Atypical orbital primary optic nerve sheath meningioma with severe disfiguring proptosis: an alternative surgical approach

Primary optic nerve sheath meningioma is generally a benign tumor. In rare instances, however, the growth rate and intraocular and intracranial extensions can be highly aggressive, especially in children, leading to poor prognosis. Here, we reported a case of a 24-year-old woman who presented with left eye swelling for 3 years. This was associated with blurred vision, retrobulbar pain, and redness. On examination, the left eye was severely proptosed with complete ophthalmoplegia. Magnetic resonance imaging showed an extensive tumor occupying the whole left orbital cavity with a disfigured eyeball. However, no intracranial extension was observed. Interestingly, complete surgical excision was feasible via transconjunctival anterior orbitotomy without bone removal. The histopathological examination confirmed the diagnosis of optic nerve sheath meningioma. Adjunct radiotherapy was given. On a follow-up after 2 years, left enophthalmos with esotropia was observed.

Primary Tumours of The Optic Disc and The Optic Disc Sheath

Primary optic nerve and optic nerve sheath tumors constitute approximately 8% of intraorbital tumors and although most of them are benign, they are manifested by findings that significantly affect visual function such as vision loss, visual field defect and proptosis. Tumors originating from the optic nerve trunk are mostly benign optic nerve glioma, but rarer tumors such as ganglioglioma, medulloepithelioma, hemangioblastoma, melanocytoma and high-grade glioblastomas such as malignant optic nerve glioma can also be detected. Tumors originating from the optic nerve sheath usually have optic nerve sheath meningioma (ONSM), of those with intraorbital and intracanalicular origin are classified as primary and intracranial ONSMs are classified as secondary tumors. Optic glioma, ONSM, and hemangioblastomas can be seen sporadically or as a component of Type 1 and Type 2 Neurofibromatosis (NF) and Von Hippel-Lindau (VHL) syndromes, respectively. Treatment with systemic chemotherapy, surgical resection and radiotherapy methods should be considered when progressive vision loss, visual field defect and cosmetically intolerable proptosis develop in optic nerve and nerve sheath tumors, which can have a quiet course for years in terms of visual function. While systemic chemotherapy is accepted as the main treatment method in optic gliomas, more successful results are obtained with specialized treatment methods such as stereotactic fractionated radiotherapy in ONSMs.

Role of hypofractionated stereotactic radiotherapy for primary optic nerve sheath meningioma.

Optic nerve sheath meningiomas (ONSM) are rare tumors potentially causing visual deficits. This study aims to report the anatomic and visual outcomes of patients with primary ONSM treated with hypofractionated stereotactic radiotherapy (HF-SRT). Data of 36 patients treated with HF-SRT between 2008 and 2019 were retrospectively collected. The clinical target volume (CTV) was equal to the gross tumor volume and a 2 mm was added for the planning target volume. All responses other than progression were accepted as local control (LC). The VA grading was performed under 3 groups to provide an even distribution; 20/400 or worse, 20/40-20/400, and 20/40 or better. Median HF-SRT dose was 25 Gy and the median CTV was 1.94 cc. After a median of 106 months of follow-up, the tumor regressed in 23 (64%), was stable in 9 (25%), and progressed in 4 (11%) eyes. The overall rate of LC was 89% with 2-, 5-, 10-, and 15-year rate of 100%, 94%, 84%, and 84%, respectively. Treatment-related late toxicity rate was 11%. The VA was stable in 27 (75%) eyes, improved in 5 (14%) eyes, and worsened in 4 (11%) eyes, respectively, after HF-SRT. Female gender was the only independent predictor of an improved VA. Hypofractionated stereotactic radiotherapy is a safe and satisfactory treatment option for primary ONSM without severe toxicity. It may be advisable to commence treatment before an established visual deficit of 20/400 or worse occurs, to make the most of the functional benefit.

Diagnostic Pearls in Case of Optic Nerve Sheath Meningioma

Diagnostic Pearls in Case of Optic Nerve Sheath Meningioma

A Novel Framework to Define and Prognosticate Visual Outcomes Following Fractionated Radiation Therapy for Optic Nerve Sheath Meningiomas

Abstract Objective: Optic nerve sheath meningiomas (ONSMs) are rare tumors that can cause significant visual problems due to their location along the optic nerve. Fractionated radiation therapy (RT) is the standard treatment, but data related to the discussion of visual outcomes are limited. No comprehensive guidelines exist to classify or define visual outcomes postoncological therapy. We propose the Wills Eye Visual Outcomes (WEVO) classification system to evaluate visual outcomes based on visual acuity, visual fields, and color vision status. Methods: We retrospectively reviewed visual and radiographic outcomes for 29 ONSMs in 27 patients who were treated with fractionated stereotactic RT between 1997 and 2012. Results: Median radiation dose of 52.2 Gy (range, 50.4-55.8). Median visual and radiographic follow-ups were 7 years (range, 1-22 y) and 6 years (range, 2-18 y), respectively. Ultimately, progression-free survival was 100% at the last follow-up. Using the WEVO criteria, visual outcomes were determined to be improved, unchanged, or worsened. At the last follow-up, 11 cases had improved vision, 10 cases had unchanged vision, and 8 cases had worsened vision. Patients aged &gt; 46, those presenting with large visual field defects, and those with color vision defects were more likely to have worsened visual outcomes following RT. Poor visual acuity at treatment and an observation time of &gt; 6 months from presenting with symptoms to RT did not significantly correlate with worsening visual outcomes. Conclusion: We provide groundwork to predict individualized risk of blindness or worsened visual outcomes in the radiation of ONSMs.

A Novel Framework to Define and Prognosticate Visual Outcomes Following Fractionated Radiation Therapy for Optic Nerve Sheath Meningiomas

Abstract Objective: Optic nerve sheath meningiomas (ONSMs) are rare tumors that can cause significant visual problems due to their location along the optic nerve. Fractionated radiation therapy (RT) is the standard treatment, but data related to the discussion of visual outcomes are limited. No comprehensive guidelines exist to classify or define visual outcomes postoncological therapy. We propose the Wills Eye Visual Outcomes (WEVO) classification system to evaluate visual outcomes based on visual acuity, visual fields, and color vision status. Methods: We retrospectively reviewed visual and radiographic outcomes for 29 ONSMs in 27 patients who were treated with fractionated stereotactic RT between 1997 and 2012. Results: Median radiation dose of 52.2 Gy (range, 50.4-55.8). Median visual and radiographic follow-ups were 7 years (range, 1-22 y) and 6 years (range, 2-18 y), respectively. Ultimately, progression-free survival was 100% at the last follow-up. Using the WEVO criteria, visual outcomes were determined to be improved, unchanged, or worsened. At the last follow-up, 11 cases had improved vision, 10 cases had unchanged vision, and 8 cases had worsened vision. Patients aged &gt; 46, those presenting with large visual field defects, and those with color vision defects were more likely to have worsened visual outcomes following RT. Poor visual acuity at treatment and an observation time of &gt; 6 months from presenting with symptoms to RT did not significantly correlate with worsening visual outcomes. Conclusion: We provide groundwork to predict individualized risk of blindness or worsened visual outcomes in the radiation of ONSMs.

Optic Nerve Sheath Meningiomas: Solving Diagnostic Challenges with 68Ga-DOTATOC PET/CT.

68Ga-DOTATOC PET could be a noninvasive, highly sensitive, and specific technique for the challenging diagnosis of optic nerve sheath meningioma (ONSM). Our objective was to report the use and results of 68Ga-DOTATOC PET in suspected ONSM. Twelve subjects who underwent 68Ga-DOTATOC PET for suspected ONSM in our department were retrospectively included. Standardised clinical and radiological data were collected. The PET examination results were classified as positive or negative, and lesion standardised uptake values (SUVmax) were recorded. 68Ga-DOTATOC PET confirmed positive uptake in six cases (SUVmax > 5), leading to ONSM diagnoses followed by radiation therapy in patients with vision loss. Six 68Ga-DOTATOC PET scans were considered negative (SUVmax < 5); these comprised one case of neurosarcoidosis, one cavernous malformation, and four uncertain diagnoses, leading to further investigation. 68Ga-DOTATOC PET was helpful in tumour volume delineation before radiation therapy, leading to a decrease in dose exposure. Noninvasive 68Ga-DOTATOC PET should be performed before treating nonhistologically proven meningiomas with radiotherapy or stereotactic radiosurgery, particularly in cases of uncertain diagnosis with MRI, which characterises most ONSM cases. PET SUVmax thresholds to distinguish meningioma from nonspecific uptake in other lesions need to be adapted to ONSM. 68Ga-DOTATOC PET improves the intraorbital lesion diagnostic approach and therefore impacts therapeutic management.