Utility of optic pathway glioma screening in young children with neurofibromatosis type I: questions generated by a clinical audit

Visual field outcomes in children treated for neurofibromatosis type 1-associated optic pathway gliomas: a multicenter retrospective study

BACKGROUND

Optic pathway gliomas associated with neurofibromatosis type 1 (NF1-OPGs) may adversely affect visual acuity, but data regarding visual field (VF) outcomes after treatment in children are limited. The purpose of this study was to investigate the effects of NF1-OPGs on VF function in a large cohort of children after treatment with chemotherapy.

METHODS

We performed a retrospective, international, multicenter study of VF outcomes in patients treated with chemotherapy for NF1-OPGs.

RESULTS

A total of 25 participants underwent VF testing using formal perimetric techniques. At the end of treatment, 19 participants (76%) had persistent VF deficits. Formal VF testing was available for 16 participants (64%) at initiation and completion of treatment. Of the 16 children who underwent VF testing at initiation and completion of treatment, 7 (44%) showed stability of VF changes, 3 (19%) showed improvement of VF function, and 6 (38%) had worsening of VFs. Improvement or worsening of VF outcome did not always correlate with visual acuity outcome. Posterior tumor location involving the optic tracts and radiations was associated with more frequent and more profound VF defects.

CONCLUSIONS

In our study cohort, children undergoing initial chemotherapy for NF1-OPGs had a high prevalence of VF loss, which could be independent of visual acuity loss. A larger, prospective study is necessary to fully determine the prevalence of VF loss and the effects of chemotherapy on VF outcomes in children with NF1-OPGs.

Role of visual evoked potentials and optical coherence tomography in the screening for optic pathway gliomas in patients with neurofibromatosis type I

PURPOSE

The purpose of the present study was to compare visual function assessment, visual evoked potential, and optical coherence tomography with measurement of retinal nerve fiber layer thickness for the diagnosis of optic pathway glioma in children with neurofibromatosis type 1.

METHODS

This retrospective observational study included patients with neurofibromatosis type 1 who underwent brain magnetic resonance imaging scan, visual evoked potential study, and peripapillary retinal nerve fiber layer evaluation by optical coherence tomography. Patients were tested with pattern-reversal visual evoked potential and with flash visual evoked potential in case of poor cooperation. Optical coherence tomography was performed with HRA Spectralis (Heidelberg Engineering, Heidelberg, Germany). The area under the curve of receiver operating characteristic curves was used to evaluate the accuracy of each parameter for diagnosing optic pathway glioma.

RESULTS

In all, 110 patients with neurofibromatosis type 1 were included in the study. Fifty of them had an optic pathway glioma diagnosed with magnetic resonance imaging, while 60 did not. Global retinal nerve fiber layer thickness demonstrated the highest diagnostic power for discriminating patients with and without optic pathway glioma (area under the curve = 0.758, sensitivity = 65.3%, specificity = 83.3%), followed visual acuity (area under the curve = 0.723, sensitivity = 51.1%, specificity = 91.7%) and P100 of visual evoked potential (area under the curve = 0.712, sensitivity = 69.6%, specificity = 63.8%).

CONCLUSION

The results of the present study showed that the measurement of retinal nerve fiber layer thickness was the most efficient test for discriminating patients with and without optic pathway glioma. Brain magnetic resonance imaging remains the gold standard to confirm the diagnosis of optic pathway glioma. Longitudinal studies are required to define if the early detection of tumors with optical coherence tomography could prevent vision loss and morbidity.

Prevalence of Strabismus Among Children With Neurofibromatosis Type 1 Disease With and Without Optic Pathway Glioma

PURPOSE

To evaluate the prevalence of strabismus in neurofibromatosis type 1 (NF-1) by comparing children with normal neuroimaging to those with optic pathway glioma.

METHODS

A retrospective data collection of all children with NF-1 with neuroimaging studies examined at a single medical center between 2000 and 2016.

RESULTS

Of the 198 children with NF-1 reviewed, 109 (55%) were male, 121 (61%) had normal neuroimaging, and 77 (39%) had an optic pathway glioma. Mean age at presentation was 6.3 ± 4.7 years and mean follow-up was 4.8 ± 3.1 years. Strabismus was present in 29 (15%) children and was significantly more prevalent in children with NF-1 with optic pathway glioma (21 of 77 [27%]) than in those with normal neuroimaging (8 of 121 [7%], P < .001). Sensory strabismus was only found in children with optic pathway glioma, accounting for most cases (12 of 21 [57%]). A strong association between strabismus and optic pathway glioma is demonstrated by an odds ratio of 5.29 (P < .001). Children with NF-1 with optic pathway glioma have a 4.13 times higher relative risk of developing strabismus than children with NF-1 without it (P = .001). The direction of ocular misalignment in children with NF-1 with optic pathway glioma was not significantly different than that observed in children without optic pathway glioma (P = .197, Fisher's exact test). Only 5 (17%) children with NF-1 with strabismus (3 with optic pathway glioma) underwent corrective surgery to align their eyes.

CONCLUSIONS

Optic pathway glioma in children with NF-1 is associated with an increased risk of strabismus that is often sensory. Although exotropia is the most common ocular misalignment associated with optic pathway glioma, the direction of strabismus cannot be used as an accurate predictor for its presence. [J Pediatr Ophthalmol Strabismus. 2019;56(1):19-22.].

Impact of vision loss among survivors of childhood central nervous system astroglial tumors

BACKGROUND

The impact of impaired vision on cognitive and psychosocial outcomes among long-term survivors of childhood low-grade gliomas has not been investigated previously but could inform therapeutic decision making.

METHODS

Data from the Childhood Cancer Survivor Study were used to investigate psychological outcomes (measures of cognitive/emotional function) and socioeconomic outcomes (education, income, employment, marital status, and independent living) among astroglial tumor survivors grouped by 1) vision without impairment, 2) vision with impairment (including unilateral blindness, visual field deficits, and amblyopia), or 3) bilateral blindness. The effect of vision status on outcomes was examined with multivariate logistic regression with adjustments for age, sex, cranial radiation therapy, and medical comorbidities.

RESULTS

Among 1233 survivors of childhood astroglial tumors 5 or more years after their diagnosis, 277 (22.5%) had visual impairment. In a multivariate analysis, survivors with bilateral blindness were more likely to be unmarried (adjusted odds ratio (OR), 4.7; 95% confidence interval [CI], 1.5-15.0), live with a caregiver (adjusted OR, 3.1; 95% CI, 1.3-7.5), and be unemployed (adjusted OR, 2.2; 95% CI, 1.1-4.5) in comparison with those without visual impairment. Bilateral blindness had no measurable effect on cognitive or emotional outcomes, and vision with impairment was not significantly associated with any psychological or socioeconomic outcomes.

CONCLUSIONS

Adult survivors of childhood astroglial tumors with bilateral blindness were more likely to live unmarried and dependently and to be unemployed. Survivors with visual impairment but some remaining vision did not differ significantly with respect to psychological function and socioeconomic status from those without visual impairment. Cancer 2016;122:730-739. © 2016 American Cancer Society.

The Use of Magnetic Resonance Imaging Screening for Optic Pathway Gliomas in Children with Neurofibromatosis Type 1

OBJECTIVE

To evaluate the utility of screening brain/orbital magnetic resonance imaging (MRI) in a large population of children with neurofibromatosis type 1 (NF1) over a 20-year period.

STUDY DESIGN

A retrospective analysis of clinical and imaging data from children with NF1 seen at a single center between 1990 and 2010 was performed.

RESULTS

During the 20-year study period, 826 individuals with NF1 (402 females, 424 males) ages 1-9 years were screened for optic pathway gliomas (OPGs) using brain/orbital MRI; 18% were identified with OPGs with a median age at detection of 3 years. Fifteen percent of patients with OPGs had radiologic or clinical progression requiring therapy. Children with chiasmatic and postchiasmatic tumors were more likely to require therapy compared with patients with prechiasmatic OPGs (P < .0001). Patients with visual deficits at the time of diagnosis were more likely to experience visual decline despite therapy when compared with patients treated based on radiologic progression (P < .012).

CONCLUSIONS

Our findings confirm that chiasmatic and postchiasmatic OPG in children with NF1 have the highest risk for progression and vision loss. Early identification of OPG by screening MRI prior to the development of vision loss may lead to improved visual outcomes. Children with negative brain and orbital MRI screening at age 15 months or later did not develop symptomatic OPGs.

Rare childhood tumors in a Turkish pediatric oncology center

Background:

It has been estimated that rare tumor rate is about 15% of all childhood cancer in United States. According to Turkish Pediatric Oncology Group (TPOG) datas, 8889 children were diagnosed between 2002 and 2008 in our country and 3.7% of them were diagnosed as rare tumors.

Aim:

To investigate the frequency and clinical features of rare tumors in our pediatric oncology center.

Materials and Methods:

A total of 43 cases that have diagnosed as rare tumor in 574 cancer patients between the yaer 2002 and 2012 were reviewed retrospectively. All cases definitive diagnosis were established by histopathological and immunohistochemical studies.

Results:

Frequency of rare tumors was 7.4% in our center. Benign and border line rare tumors were 27 (62.7%) cases, malignant rare tumor were 16 (37.2%) cases. Median follow-up period was 48 months (between 1 and 110 months). Six of the malignant rare tumors were died with progressive disease (synovial sarcoma, mixed malignant mesenchymal tumor, undifferentiated sarcoma, plexus choroideus carcinoma, renal peripheral primitive neuroectodermal tumor, adrenocortical carcinoma). Malignant rare tumor mortality rate was found 37.5% in our clinic.

Conclusion:

We have found that our rare tumor rate (7.4%) was higher than Turkish rare tumor rate (3.7%) according to TPOG's datas. However, it was still lower than rare tumor rates of western countries (15%), probably due to difficulties of diagnosis and referral problems.

Functional outcome measures for NF1-associated optic pathway glioma clinical trials

OBJECTIVE

The goal of the Response Evaluation in Neurofibromatosis and Schwannomatosis Visual Outcomes Committee is to define the best functional outcome measures for future neurofibromatosis type 1 (NF1)-associated optic pathway glioma (OPG) clinical trials.

METHODS

The committee considered the components of vision, other ophthalmologic parameters affected by OPG, potential biomarkers of visual function, and quality of life measures to arrive at consensus-based, evidence-driven recommendations for objective and measurable functional endpoints for OPG trials.

RESULTS

Visual acuity (VA) assessments using consistent quantitative testing methods are recommended as the main functional outcome measure for NF1-OPG clinical trials. Teller acuity cards are recommended for use as the primary VA endpoint, and HOTV as a secondary endpoint once subjects are old enough to complete it. The optic disc should be assessed for pallor, as this appears to be a contributory variable that may affect the interpretation of VA change over time. Given the importance of capturing patient-reported outcomes in clinical trials, evaluating visual quality of life using the Children's Visual Function Questionnaire as a secondary endpoint is also proposed.

CONCLUSIONS

The use of these key functional endpoints will be essential for evaluating the efficacy of future OPG clinical trials.

Fractional anisotropy of the optic radiations is associated with visual acuity loss in optic pathway gliomas of neurofibromatosis type 1

BACKGROUND

No more than half of patients with neurofibromatosis type 1 (NF1)-associated optic pathway gliomas (OPGs) develop vision loss. Prospectively identifying those who will require therapy remains challenging, because no reliable factors have yet been identified that predict future vision loss. To determine whether brain tissue microstructure is associated with visual acuity loss, we examined diffusion tensor imaging (DTI) and ophthalmologic evaluations in children with NF1-associated OPG.

METHODS

We retrospectively reviewed ophthalmology records and concurrent DTI measurements of the optic nerves, tracts, and radiations from 50 children with NF1-associated OPGs. Multivariate linear regression measured the association between fiber trajectory quantity and white matter integrity on visual acuity measured by the logarithm of the minimal angle of resolution (logMAR).

RESULTS

In multivariate analysis, fractional anisotropy (FA) of the optic radiations was associated with visual acuity loss (adjusted coefficient = -6.081 logMAR/FA; P = .006) after adjusting for age, extent of tumor, DTI acquisition type, prior chemotherapy, and fundus examination findings. The association remained after eliminating tumors involving the optic radiations. In an evaluation of 15 subjects with paired ophthalmologic examination and DTI a year apart, initial FA of the optic radiation was associated with a trend toward change in visual acuity a year later (coefficient = -2.652 logMAR/FA; P = .069).

CONCLUSIONS

A decrease in FA of the optic radiations is associated with abnormal visual acuity in NF1-associated OPGs and may be predictive of visual acuity loss during the following year.