MRI of retinoblastoma

Retinoblastoma - A comprehensive review, update and recent advances

Retinoblastoma is the most common pediatric ocular malignancy. It is triggered by a biallelic mutation in the RB1 gene or MYCN oncogene amplification. Retinoblastomas can be unilateral (60%-70%) or bilateral (30%-40%); bilateral tumors are always heritable and present at an earlier age as compared to unilateral ones (18-24 months vs. 36 months in India). High prevalence rates, delayed presentation, and inaccessibility to healthcare lead to worse outcomes in developing countries. The past few decades have seen a paradigm change in the treatment of retinoblastomas, shifting from enucleation and external beam radiotherapy to less aggressive modalities for eye salvage. Multimodality treatment is now the standard of care and includes intraarterial or intravenous chemotherapy along with focal consolidation therapies such as transpupillary thermotherapy, cryotherapy, and laser photocoagulation. Intravitreal and intracameral chemotherapy can help in controlling intraocular seeds. Advanced extraocular or metastatic tumors still have a poor prognosis. Genetic testing, counseling, and screening of at-risk family members must be incorporated as essential parts of management. A better understanding of the genetics and molecular basis of retinoblastoma has opened up the path for potential targeted therapy in the future. Novel recent advances such as liquid biopsy, prenatal diagnosis, prognostic biomarkers, tylectomy, and chemoplaque point to promising future directions.

Pediatric orbital lesions: ocular pathologies

Orbital pathologies can be broadly classified as ocular, extra-ocular soft-tissue (non-neoplastic and neoplastic), osseous, and traumatic. In part 1 of this orbital series, the authors will discuss the differential diagnosis and key imaging features of pediatric ocular pathologies. These include congenital and developmental lesions (microphthalmos, anophthalmos, persistent fetal vasculature, coloboma, morning glory disc anomaly, retinopathy of prematurity, Coats disease), optic disc drusen, infective and inflammatory lesions (uveitis, toxocariasis, toxoplasmosis), and ocular neoplasms (retinoblastoma, retinal hamartoma, choroidal melanoma, choroidal nevus). This pictorial review provides a practical approach to the imaging work-up of these anomalies with a focus on ocular US as the first imaging modality and additional use of CT and/or MRI for the evaluation of intracranial abnormalities. The characteristic imaging features of the non-neoplastic mimics of retinoblastoma, such as persistent fetal vasculature and Coats disease, are also highlighted.

Magnetic resonance imaging in paediatric ocular and orbital lesions: A pictorial review

Paediatric orbital lesions encompass a wide spectrum of benign and malignant entities that can arise from different components of the orbit. Clinical symptoms and signs are often nonspecific, and imaging plays a crucial role in the diagnosis and management. Ultrasonography has a limited role and radiation is a major concern with CT especially in the paediatric population. MRI is the modality of choice that avoids the radiation hazard and provides superior soft tissue contrast. The lesions can be localized using the 'compartment' approach which helps to narrow the list of differentials. MRI also provides critical information for management such as presence of perineural spread and intracranial extension. This article depicts the spectrum of Magnetic Resonance imaging findings encountered in paediatric ocular and orbital lesions.

Imaging of pediatric calvarial and skull base tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

A standardized imaging protocol for pediatric oncology patients is essential for accurate and efficient imaging, while simultaneously promoting collaborative understanding of pathologies and radiologic assessment of treatment response. The objective of this article is to provide standardized pediatric imaging guidelines and parameters for evaluation of tumors of the pediatric orbit, calvarium, skull base, and temporal bone. This article was drafted based on current scientific literature as well as consensus opinions of imaging experts in collaboration with the Children's Oncology Group Diagnostic Imaging Committee, Society of Pediatric Radiology Oncology Committee, and American Society of Pediatric Neuroradiology.

Orbital Tumors-Clinical, Radiologic and Histopathologic Correlation

Orbital masses include a broad spectrum of benign and malignant entities. Often these masses are asymptomatic or show a slow growth rate, so that emergence of clinical symptoms is prolonged. In this context, cross-sectional imaging plays an elementary role in the characterization of these lesions. Aside from the characterization of the underlying entity, an evaluation of the involved compartments is possible by sufficient imaging, which also facilitates optimal treatment and surgery planning. The purpose of this review is to explore different benign and malignant orbital tumors and their typical appearance in imaging together with histopathologic findings.

Magnetic resonance imaging of the orbit, Part 2: Characterization of orbital pathologies

In this article we focus on a systematic approach to assess common orbital lesions on magnetic resonance imaging (MRI). The identification of the probable compartment or structure of origin helps narrow the differential diagnosis of a lesion. Analyzing the morphology, appearance, and signal intensity on various sequences, the pattern, and degree of contrast enhancement are key to characterize lesions on MRI. Imaging features suggesting cellularity and vascularity can also be determined to help plan for biopsy or surgery of these lesions. MRI can also distinguish active from chronic disease in certain pathologies and aids in selecting appropriate medical management. MRI may thus serve as a diagnostic tool and help in guiding therapeutic strategies and posttreatment follow-up.

Carotid disease and retinal optical coherence tomography angiography parameters in patients with non-arteritic anterior ischemic optic neuropathy

PURPOSE

In order to analyze the data and retinal microvasculature for non-arteritic anterior ischemic optic neuropathy (NAION), patients were referred to have carotid Doppler ultrasound (CDU) from 2016 to 2020.

METHODS

In this case-control observational study, 30 NAION patients were evaluated with CDU. Twenty-two NAION patients (at least 3 months after the onset of symptoms) and 9 normal subjects underwent a complete ophthalmic examination including optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A). NAION eyes and fellow eyes were further divided into two groups based on the presence of carotid stenosis (CS). NAION patients with CS were termed "CS-NAION"; and those without CS were termed "NCS-NAION." Measurements of radial peripapillary capillary vessel density (RPC VD), ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thicknesses were compared among groups.

RESULTS

Fourteen of 30 NAION patients referred to have carotid Doppler were positive for CS with each one of such referrals having less than 50% stenosis. RNLF, GCC and RPC VDs were reduced in NAION patients' eyes, when compared to controls and the fellow eyes. RPC VD was significantly lower in the temporal-superior (P = 0.037) and the superior-temporal (P = 0.012) sectors of the NCS-NAION patients than in the CS-NAION patients. No significant differences were found between CS-fellow eyes and NCS-fellow eyes in terms of RPC VDs, RNLF or GCC.

CONCLUSION

Results of the study highlight the effect of the carotid artery stenosis on ocular perfusion pressure in the pathogenesis of NAION. More extensive studies are necessary.

Neuroimaging in Children with Ophthalmological Complaints: A Review

Pediatric patients are commonly referred to imaging following abnormal ophthalmological examinations. Common indications include papilledema, altered vision, strabismus, nystagmus, anisocoria, proptosis, coloboma, and leukocoria. Magnetic resonance imaging (MRI) of the brain and orbits (with or without contrast material administration) is typically the imaging modality of choice. However, a cranial CT scan is sometimes initially performed, particularly when MRI is not readily available. Familiarity with the various ophthalmological conditions may assist the radiologist in formulating differential diagnoses and proper MRI protocols afterward. Although MRI of the brain and orbits usually suffices, further refinements are sometimes warranted to enable suitable assessment and accurate diagnosis. For example, the assessment of children with sudden onset anisocoria associated with Horner syndrome will require imaging of the entire oculosympathetic pathway, including the brain, orbits, neck, and chest. Dedicated orbital scans should cover the area between the hard palate and approximately 1 cm above the orbits in the axial plane and extend from the lens to the midpons in the coronal plane. Fat-suppressed T2-weighted fast spin echo sequences should enable proper assessment of the globes, optic nerves, and perioptic subarachnoid spaces. Contrast material should be given judiciously, ideally according to clinical circumstances and precontrast scans. In this review, we discuss the major indications for imaging following abnormal ophthalmological examinations.

Histopathological assessment of optic nerve invasion guided by radiological findings in enucleated globes with retinoblastoma

Background

Optic nerve (ON) invasion is an important high-risk feature, and an indicator for neoadjuvant chemotherapy and prognosis. We aim through this study to correlate the detected-ON invasion by Magnetic resonance imaging (MRI) with the corresponding confirmed histopathological level of invasion.

Methods

A retrospective study of enucleated globes with the diagnosis of retinoblastoma received in the histopathology department(s) from January 2015 to December 2016 (2 years). Slides were reviewed for ON invasion assessment, charts were reviewed for basic demographic data. All patients underwent MRI under sedation upon diagnosis and MRI findings were collected for the above correlation.

Results

A total of 38 patients were included: 21 males and 17 females. 29 (77.3%) had unilateral involvement, 7 (18.4%) had bilateral involvement and 2 cases had trilateral disease. The overall mean age at diagnosis was 22.63 ± 15.15 months. Histopathological examination revealed ON invasion in 28 cases (74%) distributed as follows: prelaminar (31.6%), laminar (18.4%), and post-laminar (23.7%). MRI confirmed post-laminar ON invasion in 8 cases (true positive) but failed to detect this in 1 case. Additionally, MRI detected another 8 cases of ON invasion that were false positive on histopathology (accuracy: 63.3%; sensitivity: 88.9%; specificity: 72.4%; Positive predictive value (PPV): 50%; Negative predictive value (NPV): 95.5%).

Conclusions

MRI is found to be less sensitive in evaluating prelaminar and laminar ON invasion (0.0 and 42.9%) compared to post-laminar invasion (88.9%). MRI has generally better specificity in detecting ON invasion irrespective of the invasion level. In our study, obtaining deeper and/or additional histologic sections from the other surface of the tissue block in cases where a post-laminar ON invasion by MRI is found but not confirmed histopathologically in routine sections is essential to avoid missing such an important high-risk feature.

Novel observations in choroidal osteoma by multispectral imaging: a pilot case series

PURPOSE

To identify novel tumor-specific features of ossification by using multispectral imaging (MSI) in patients diagnosed with choroidal osteoma.

METHODS

Six eyes of 5 patients previously diagnosed with choroidal osteoma by ocular ultrasonography and orbital computerized tomography were observed with multispectral imaging (MSI). Traditional multimodal imaging, including color fundus photograph (CFP) and enhanced depth-imaging-optical coherence tomography (EDI-OCT), fundus autofluorescence (FAF), indocyanine green angiography/fundus fluorescein angiography (ICGA/FFA), was performed. Osseous features detected by MSI such as calcification and decalcification were characterized and compared with other imaging modalities.

RESULTS

In all 3 eyes with calcified choroidal osteoma (100%), MSI featured by the homogeneous reflectance in 550 nm but the beehive appearance in 600-680 nm and homogenous hyper-reflectance in 780-850 nm', indicating the compact bone in the outer layers and bone trabecula in the middle layer (Sandwich sign). The pigmentary change showed high agreement between MSI and FAF. In other 3 eyes with extensive decalcification, MSI was able to differentiate the inactive portion of the osteoma from the decalcified area. The inactive portion was characterized by geographic hyper-reflective islands with higher reflectivity border (floating island sign). Decalcified portion was featured by increased definition and reflectivity from osteoma. Partial decalcification and total decalcification can be differentiated in one decalcifying eye (33.3%). MSI revealed better the presence and border of the osteoma compared with FFA, FAF and MC (100%) in all six eyes in our study.

CONCLUSIONS

MSI presented characteristic osseous-related features of choroidal osteoma, providing clear evidence for differentiating osteoblastic and osteoclastic regions and noncalcifying regions. It can contribute to en-face visualization of choroidal osteomas at different stages, providing new insight into the spectrum behavior of CO.

Apolipoprotein A1 and B as risk factors for development of intraocular metastasis in patients with breast cancer

Objective: Breast cancer is the most common primary lesion resulting in intraocular metastasis (IOM). In this study, we investigated the differences between breast cancer patients with and without IOM, and clarified the risk factors for IOM in patients with breast cancer.

Methods: A total of 2,381 patients with breast cancer were included in this study from January 2005 to December 2017. The chi-square test and Student’s t-test were applied to evaluate differences between the IOM and non-IOM (NIOM) groups. Risk factors were calculated using binary logistic regression analysis. Receiver operating curve (ROC) analysis was used to assess the diagnostic value of IOM in patients with breast cancer.

Results: The IOM incidence in patients with breast cancer was 1.35%. No significant differences were detected in age, gender, menopausal status, or histopathology between the IOM and NIOM groups. The IOM group had more axillary lymph node metastases, lower ApoA1 and higher ApoB, compared with the NIOM group. Binary logistic regression indicated that ApoA1 and ApoB were risk factors for IOM in breast cancer patients (P-values<0.001 and P-values=0.005, respectively). ROC curve analysis revealed area under the curve values for ApoA1 and ApoB of 0.871 and 0.633, using cutoff values of 1.165 and 0.835 g/L, respectively. The sensitivity and specificity values for ApoA1 were 0.813 and 0.849, respectively, while those for ApoB were 0.813 and 0.481.

Conclusion: Our data indicate that ApoA1 and ApoB are risk factors for IOM in patients with breast cancer and that ApoA1 is more reliable than ApoB at distinguishing IOM from NIOM in patients with breast cancer.

Retinoblastoma, the visible CNS tumor: A review

The pediatric ocular cancer retinoblastoma is the only central nervous system (CNS) tumor readily observed without specialized equipment: it can be seen by, and in, the naked eye. This accessibility enables unique imaging modalities. Here, we review this cancer for a neuroscience audience, highlighting these clinical and research imaging options, including fundus imaging, optical coherence tomography, ultrasound, and magnetic resonance imaging. We also discuss the subtype of retinoblastoma driven by the MYCN oncogene more commonly associated with neuroblastoma, and consider trilateral retinoblastoma, in which an intracranial tumor arises along with ocular tumors in patients with germline RB1 gene mutations. Retinoblastoma research and clinical care can offer insights applicable to CNS malignancies, and also benefit from approaches developed elsewhere in the CNS.

The predictive value of magnetic resonance imaging of retinoblastoma for the likelihood of high-risk pathologic features

PURPOSE:

To evaluate the predictive value of magnetic resonance imaging in retinoblastoma for the likelihood of high-risk pathologic features.

METHODS:

A retrospective study of 64 eyes enucleated from 60 retinoblastoma patients. Contrast-enhanced magnetic resonance imaging was performed before enucleation. Main outcome measures included demographics, laterality, accuracy, sensitivity, and specificity of magnetic resonance imaging in detecting high-risk pathologic features.

RESULTS:

Optic nerve invasion and choroidal invasion were seen microscopically in 34 (53%) and 28 (44%) eyes, respectively, while they were detected in magnetic resonance imaging in 22 (34%) and 15 (23%) eyes, respectively. The accuracy of magnetic resonance imaging in detecting prelaminar invasion was 77% (sensitivity 89%, specificity 98%), 56% for laminar invasion (sensitivity 27%, specificity 94%), 84% for postlaminar invasion (sensitivity 42%, specificity 98%), and 100% for optic cut edge invasion (sensitivity100%, specificity 100%). The accuracy of magnetic resonance imaging in detecting focal choroidal invasion was 48% (sensitivity 33%, specificity 97%), and 84% for massive choroidal invasion (sensitivity 53%, specificity 98%), and the accuracy in detecting extrascleral extension was 96% (sensitivity 67%, specificity 98%).

CONCLUSIONS AND RELEVANCE:

Magnetic resonance imaging should not be the only method to stratify patients at high risk from those who are not, eventhough it can predict with high accuracy extensive postlaminar optic nerve invasion, massive choroidal invasion, and extrascleral tumor extension.

Performance of apparent diffusion coefficient of medial and lateral rectus muscles in Graves' orbitopathy

Objective The purpose of this study was to determine the performance of the apparent diffusion coefficient in the detection of involvement of the medial and lateral rectus muscles in patients with Graves' orbitopathy. Methods and materials This prospective study was conducted on 33 consecutive patients (16 males, 17 females with a mean age of 36 years) with Graves' orbitopathy and 18 age- and sex-matched volunteers. The patients and volunteers underwent diffusion-weighted magnetic resonance imaging of the orbit in the axial plane using echo-planar imaging. The apparent diffusion coefficient of the medial and lateral rectus muscles was calculated. Results The medial rectus muscle was more affected than the lateral rectus muscle. The mean apparent diffusion coefficient value of the medial and lateral rectus muscles was 1.81 ± 0.19 and 1.72 ± 0.07 × 10^-3mm²/s in patients with Graves' orbitopathy and 1.59 ± 0.06 and 1.51 ± 0.06 × 10^-3 mm²/s in volunteers, respectively. There was a significant difference in apparent diffusion coefficient values of the medial and lateral rectus muscles between patients with Graves' orbitopathy and volunteers ( p = 0.001). The classification performance as measured with area under the receiver operator characteristic curve was 0.89 (95% confidence interval: 0.732-0.904). The best performing threshold of the apparent diffusion coefficient value of the medial rectus muscle was 1.69 × 10^-3 mm²/s and associated efficiency was 86%, sensitivity was 97%, and specificity was 97%. Conclusion We concluded that the apparent diffusion coefficient of the medial rectus muscle can be used for diagnosis of Graves' orbitopathy.

Sonographic Detection of Unilateral Retinoblastoma

Retinoblastoma is a cancer that affects the eye, and if untreated, it can spread to other parts of the body. Retinoblastoma is the most common pediatric eye cancer and accounts for 3% of all childhood cancers. It can be hereditary or sporadic (nonhereditary). This case study presents a unilateral retinoblastoma of the right eye in a pediatric patient. A diagnosis of retinoblastoma was made by correlating sonography, magnetic resonance imaging, and ophthalmology. Treatment for retinoblastoma depends on the severity of the cancer but can include radiation, chemotherapy, focal laser therapy, and/or surgery. This particular case of retinoblastoma was treated with chemotherapy.

Magnetic resonance imaging of optic nerve

Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI), plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies.

Bilateral persistent fetal vasculature due to a mutation in the Norrie disease protein gene

We report a case of a 7-week-old boy with bilateral leukocoria and asymmetric microphthalmia who was found to have Norrie disease. Symmetrically hyperdense globes with no evidence of calcification were seen on CT scan. The MRI showed bilateral retinal hemorrhages resulting in conical vitreous chambers-narrow at the optic disc and widened toward the lens-characteristic of persistent fetal vasculature. Genetic evaluation revealed a previously undescribed mutation in the Norrie disease protein gene.

Recent advances in management of retinoblastoma: A review

The management of retinoblastoma has evolved significantly over recent years. Current treatment options aim to preserve the globe as well as vision with minimum morbidity. High resolution imaging has improved tumor detection and is useful for prognosticating cases and monitoring response to treatment. Targeted chemotherapy such as intra-arterial and intra-vitreal chemotherapy has shown promising results and these routes are being increasingly employed world-wide for globe preservation. The advent of new radiotherapy techniques has led to improved radiation delivery to the target and more conformal treatment plans with better normal tissue sparing. This review aims to highlight newer advancements in the field of diagnosis and management of retinoblastoma that have been introduced in recent times, with a special emphasis on globe-preserving therapy.

Correlation of apparent diffusion coefficient at 3T with prognostic parameters of retinoblastoma

BACKGROUND AND PURPOSE

Pathologic prognostic parameters for retinoblastoma have been defined. Our purpose was to correlate ADC values at 3T with prognostic parameters of retinoblastoma.

MATERIALS AND METHODS

This study included 72 children (30 boys and 42 girls, mean age 19 ± 2.6 months) with retinoblastoma. Pretreatment diffusion-weighted MR imaging was performed on a 3T scanner with b factors of 0, 500, and 1000 seconds/mm(2). ADC values were calculated and pathologic specimens were analyzed. ADC values of the tumors were then correlated with prognostic parameters, including degree of histologic differentiation, tumor size, bilaterality, choroidal invasion, and optic nerve extension.

RESULTS

The mean ADC value of retinoblastoma was 0.49 ± 0.12 × 10(-3) mm(2)/s. The ADC values of well- and moderately differentiated tumors were significantly different (P = .007) from poorly and undifferentiated retinoblastoma. There was also a significant difference in the ADC value among small, medium, and large tumors (P = .015), as well as between unilateral and bilateral retinoblastoma (P = .001), and this was independent of the degree of differentiation. The ADC value was also significantly lower (P = .003) when optic nerve invasion was present. There was no correlation of ADC value with growth pattern or choroidal invasion (P = .640 and 0.661, respectively). The ADC value of retinoblastoma was well correlated with the degree of differentiation of the tumor (r = 0.87, P = .007) and inversely correlated with the size of the tumor (r = -0.68, P = .015).

CONCLUSIONS

ADC correlated with some of the accepted parameters of poor prognosis for retinoblastoma and may serve as a noninvasive prognostic parameter for assessment of newly diagnosed retinoblastoma.