Diagnostic Performance of Magnetic Resonance Imaging and Computed Tomography for Advanced Retinoblastoma

Optic nerve thickening on high-spatial-resolution MRI predicts early-stage postlaminar optic nerve invasion in retinoblastoma

OBJECTIVES

To assess the diagnostic accuracy of nerve thickening on MRI to predict early-stage postlaminar optic nerve invasion (PLONI) in retinoblastoma. Furthermore, this study aimed to incorporate measurements into a multiparametric model for radiological determination of PLONI.

METHODS

In this retrospective multicenter case-control study, high-spatial-resolution 3D T2-weighted MR images were used to measure the distal optic nerve. Histopathology was the reference standard for PLONI. Two neuroradiologists independently measured the optic nerve width, height, and surface at 0, 3, and 5 mm from the most distal part of the optic nerve. Subsequently, PLONI was scored on contrast-enhanced T1-weighted and 3D T2-weighted images, blinded for clinical data. Optic nerve measurements with the highest diagnostic accuracy for PLONI were incorporated into a prediction model for radiological determination of PLONI.

RESULTS

One hundred twenty-four retinoblastoma patients (median age, 22 months [range, 0-113], 58 female) were included, resulting in 25 retinoblastoma eyes with histopathologically proven PLONI and 206 without PLONI. ROC analysis of axial optic nerve width measured at 0 mm yielded the best area under the curve of 0.88 (95% confidence interval: 0.79, 0.96; p < 0.001). The optimal width cutoff was ≥ 2.215 mm, with a sensitivity of 84% (95% CI: 64, 95%) and specificity of 83% (95% CI: 75, 89%) for detecting PLONI. Combining width measurements with the suspicion of PLONI on MRI sequences resulted in a prediction model with an improved sensitivity and specificity of respectively up to 88% and 92%.

CONCLUSION

Postlaminar optic nerve thickening can predict early-stage postlaminar optic nerve invasion in retinoblastoma.

CLINICAL RELEVANCE STATEMENT

This study provides an additional tool for clinicians to help determine postlaminar optic nerve invasion, which is a risk factor for developing metastatic disease in retinoblastoma patients.

KEY POINTS

• The diagnostic accuracy of contrast-enhanced MRI for detecting postlaminar optic nerve invasion is limited in retinoblastoma patients. • Optic nerve thickening can predict postlaminar optic nerve invasion. • A prediction model combining MRI features has a high sensitivity and specificity for detecting postlaminar optic nerve invasion.

Histone Deacetylases in Retinoblastoma

Retinoblastoma, a pediatric ocular malignancy, presents significant challenges in comprehending its molecular underpinnings and targeted therapeutic approaches. The dysregulated activity of histone deacetylases (HDACs) has been associated with retinoblastoma pathogenesis, influencing critical cellular processes like cell cycle regulation or retinal ganglion cell apoptosis. Through their deacetylase activity, HDACs exert control over key tumor suppressors and oncogenes, influencing the delicate equilibrium between proliferation and cell death. Furthermore, the interplay between HDACs and the retinoblastoma protein pathway, a pivotal aspect of retinoblastoma etiology, reveals a complex network of interactions influencing the tumor microenvironment. The examination of HDAC inhibitors, encompassing both established and novel compounds, offers insights into potential approaches to restore acetylation balance and impede retinoblastoma progression. Moreover, the identification of specific HDAC isoforms exhibiting varying expression in retinoblastoma provides avenues for personalized therapeutic strategies, allowing for interventions tailored to individual patient profiles. This review focuses on the intricate interrelationship between HDACs and retinoblastoma, shedding light on epigenetic mechanisms that control tumor development and progression. The exploration of HDAC-targeted therapies underscores the potential for innovative treatment modalities in the pursuit of more efficacious and personalized management strategies for this disease.

Diagnostic Imaging for Retinoblastoma Cancer Staging: Guide for Providing Essential Insights for Ophthalmologists and Oncologists

Retinoblastoma is the most common cause of all intraocular pediatric malignancies. It is caused by the loss of RB1 tumor suppressor gene function, although some tumors occur due to MYCN oncogene amplification with normal RB1 genes. Nearly half of all retinoblastomas occur due to a hereditary germline RB1 pathogenic variant, most of which manifest with bilateral tumors. This germline RB1 mutation also predisposes to intracranial midline embryonal tumors. Accurate staging of retinoblastoma is crucial in providing optimal vision-, eye-, and life-saving treatment. The AJCC Cancer Staging Manual has undergone significant changes, resulting in a universally accepted system with a multidisciplinary approach for managing retinoblastoma. The authors discuss the role of MRI and other diagnostic imaging techniques in the pretreatment assessment and staging of retinoblastoma. A thorough overview of the prevailing imaging standards and evidence-based perspectives on the benefits and drawbacks of these techniques is provided. Published under a CC BY 4.0 license. Test Your Knowledge questions for this article are available in the supplemental material.

Preoperative Detection of Local Tumor Extent in Patients with Advanced Retinoblastoma: Predictive Value of MRI and Clinical Findings

OBJECTIVE

Before planned enucleation, local tumor extension in advanced retinoblastoma is routinely assessed preoperatively using high-resolution magnetic resonance imaging (MRI). The aim of our study was to analyse the predictive value of MRI and clinical characteristics for predicting tumor extent, as confirmed by histopathology postoperatively.

PATIENTS AND METHODS

All consecutive patients were included who underwent primary enucleation for advanced retinoblastoma after high-resolution MRI examination in our hospital between January 2011 and December 2021. The primary study endpoint was the evaluation of the predictability of histopathological risk factors on preoperative MRI examination. The sensitivity and specificity of the MRI examination with respect to clinically relevant optic nerve infiltration and choroidal infiltration were determined.

RESULTS

The mean age of the 209 included patients was 1.6 years (range 1 month to 4.7 years). MRI indicated optic nerve infiltration in 46 (22%) patients, extensive choroidal infiltration in 78 (40.2%) patients, and scleral infiltration in one patient (2.6%). Histopathological examination demonstrated postlaminar optic infiltration in 25 (12%) patients and extensive choroidal infiltration in 17 (8.1%) cases. Scleral infiltration was evident in 8 (3.8%) patients. In the final multivariate analysis, MRI findings of tumor infiltration and a preoperative intraocular pressure ≥ 20 mmHg were independently associated with histopathological evidence of clinically relevant optic nerve (p = 0.033/p = 0.011) and choroidal infiltration (p = 0.005/p = 0.029). The diagnostic accuracy of the prediction models based on the multivariate analysis for the identification of the clinically relevant optic nerve (AUC = 0.755) and choroidal infiltration (AUC = 0.798) was greater than that of purely MRI-based prediction (respectively 0.659 and 0.742). The sensitivity and specificity of MRI examination for determining histopathological risk factors in our cohort were 64% and 65% for clinically relevant optic infiltration and 87% and 64% for clinically relevant choroidal infiltration.

CONCLUSION

The local tumor extent of retinoblastoma with infiltration of the optic nerve and choroid can be well estimated based on radiological and clinical characteristics before treatment initiation. The combination of clinical and radiological risk factors supports the possibility of early treatment stratification in retinoblastoma patients.

Changing trends in pseudoretinoblastoma diagnoses: A 10 year review from the United Kingdom

AIM

To study the different types and frequency of pseudoretinoblastoma (pseudoRB) lesions who present to a retinoblastoma centre due to concern that the condition may be retinoblastoma.

METHODS

A retrospective chart review of 341 patients presenting sporadically to the Royal London Hospital from January 2009 to December 2018.

RESULTS

220 patients (65%) were confirmed to have retinoblastoma, while 121 (35%) had pseudoRB. There were 23 differential diagnoses in total. The top 3 differential diagnoses were Coats' disease (34%), Persistent Foetal Vasculature (PFV) (17%) and Combined Hamartoma of Retina and Retinal Pigment Epithelium (CHR-RPE) (13%). PseudoRBs differed with age at presentation. Under the age of 1 (n = 42), the most likely pseudoRB conditions were PFV (36%), Coats' disease (17%) and CHR-RPE (12%). These conditions were also the most common simulating conditions between the ages of 1 and 2 (n = 21), but Coats' disease was the most common in this age group (52%), followed by CHR-RPE (19%) and PFV (14%). Between the ages of 2 and 5 (n = 32), Coats' disease remained the most common (44%) pseudoRB lesion followed by CHR-RPE (13%), or PFV, Retinal Astrocytic Hamartoma (RAH), familial exudative vitreoretinopathy (FEVR) (all 6.3%). Over the age of 5 (n = 26), pseudoRBs were most likely to be Coats' disease (35%), RAH (12%), Uveitis, CHR-RPE, FEVR (all 7.7%).

CONCLUSION

35% of suspected retinoblastoma cases are pseudoRB conditions. Overall, Coats' disease is the most common pseudoRB condition, followed by PFV. Hamartomas (CHR-RPE & RAH) are more prevalent in this cohort, reflecting improvements in diagnostic accuracy from referring ophthalmologists.

[Imaging of retinoblastoma : Current state-of-the-art and future prospects]

BACKGROUND

Retinoblastoma is the most common malignant eye tumor in children and is associated with tumor predisposition syndrome (RB1 mutation) in up to 40% of cases. Imaging is an important part of the diagnostic workup of children with retinoblastoma both during the initial diagnosis and follow-up.

OBJECTIVES

The goal of this review is to present the current state-of-the-art regarding imaging of children with retinoblastoma, including technical background and diagnostic clues with a brief discussion of future prospects. In addition, we summarize the general clinical diagnostic workup and therapeutic options.

MATERIALS AND METHODS

Review of the literature and our own experience in the imaging of retinoblastoma.

CONCLUSION

High-resolution magnetic resonance imaging (MRI) is the imaging modality of choice in children with retinoblastoma for diagnosis (estimation of diagnosis/differential diagnosis, evaluation of local and intracranial tumor extension) and during follow-up. Despite the characteristic calcifications, computed tomography (CT) examinations are no longer indicated in these patients. Due to the high association with tumor predisposition syndrome, genetic counselling is recommended.

Diffusion‐Weighted MR Imaging of the Optic Nerve Can Improve the Detection of Post‐Laminar Optic Nerve Invasion from Retinoblastoma

BACKGROUND

Post-laminar optic nerve invasion (PLONI) is a high-risk factor for the metastasis of retinoblastoma (RB). Unlike conventional MRI, diffusion-weighted imaging (DWI) reflects histopathological features, and may aid the assessment of PLONI.

PURPOSE

To determine the value of conventional MRI plus DWI in detecting PLONI in RB patients.

STUDY TYPE

Retrospective.

POPULATION

Eighty-three RB patients, including 28 with histopathologically proven PLONI and 55 without PLONI.

FIELD STRENGTH/SEQUENCE

3.0 T, precontrast axial T1-weighted and T2-weighted imaging, DWI, and postcontrast axial, coronal, and oblique-sagittal T1-weighted imaging.

ASSESSMENT

PLONI was assessed using post-enucleation histology and preoperative MRI features (optic nerve signal intensity, enlargement, and enhancement on conventional MRI, and apparent diffusion coefficient [ADC] of the optic nerve on DWI) evaluated by three observers.

STATISTICAL TESTS

MRI features suggesting the presence of PLONI were identified using univariable and multivariable analyses. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to analyze diagnostic performance.

RESULTS

Optic nerve enhancement and low ADC of the optic nerve were significant indicators of PLONI. ROC curve analysis showed that the AUC of the combination of these two features for detecting PLONI was 0.87 (95% confidence interval [CI]: 0.78-0.93). The diagnostic performance of this model was significantly superior to that of optic nerve enhancement alone (0.76, 95% CI: 0.65-0.85) and marginally superior to that of the ADC of the affected optic nerve (0.78, 95% CI: 0.68-0.87, P = 0.051).

DATA CONCLUSION

Conventional MRI combined with DWI can improve the detection of PLONI in RB patients over conventional MRI alone.

EVIDENCE LEVEL

3 Technical Efficacy: Stage 2.

A case of retinoblastoma resulting in phthisis bulbi after proton beam radiation therapy

Purpose

Proton beam radiation therapy (PBRT) is a treatment option for advanced retinoblastoma (RB) resistant to chemotherapy and focal ophthalmic treatment. Here we report a case of RB with phthisis bulbi following PBRT.

Observations

A 16-day-old boy with a family history of RB was referred to our institution. Initial examination revealed an extensive white mass in the right eye and a small tumor near the optic disk of the left eye. The patient was diagnosed with bilateral RB and treated with chemotherapy and focal ophthalmic therapy. The right eye showed shrinkage in the treatment course. The tumor control was not achieved bilaterally, and, therefore, PBRT was performed to preserve the eyes. However, the right eye became significantly phthisical following PBRT and ultimately required enucleation.

Conclusions and importance

PBRT for RB may result in phthisis bulbi. Further investigations of its role and possible complications are warranted.

Nanotechnology for Pediatric Retinoblastoma Therapy

Retinoblastoma is a rare, sometimes hereditary, pediatric cancer. In high-income countries this disease has a survival rate approaching 100%, while in low- and middle-income countries the prognosis is fatal for about 80% of cases. Depending on the stage of the disease, different therapeutic protocols are applied. In more advanced forms of the disease, surgical removal of the entire globe and its intraocular contents (enucleation) is, unfortunately, necessary, whereas in other cases, conventional chemotherapy is normally used. To overcome the side-effects and reduced efficacy of traditional chemotherapic drugs, nanodelivery systems that ensure a sustained drug release and manage to reach the target site have more recently been developed. This review takes into account the current use and advances of nanomedicine in the treatment of retinoblastoma and discusses nanoparticulate formulations that contain conventional drugs and natural products. In addition, future developments in retinoblastoma treatment are discussed.

High-risk Pathologic Features Based on Presenting Findings in Advanced Intraocular Retinoblastoma: A Multicenter, International Data-Sharing American Joint Committee on Cancer Study

PURPOSE

To determine the value of clinical features for advanced intraocular retinoblastoma as defined by the eighth edition of the American Joint Committee on Cancer (AJCC) cT3 category and AJCC Ophthalmic Oncology Task Force (OOTF) Size Groups to predict the high-risk pathologic features.

DESIGN

International, multicenter, registry-based retrospective case series.

PARTICIPANTS

Eighteen ophthalmic oncology centers from 13 countries over 6 continents shared evaluations of 942 eyes enucleated as primary treatment for AJCC cT3 and, for comparison, cT2 retinoblastoma.

METHODS

International, multicenter, registry-based data were pooled from patients enrolled between 2001 and 2013. High-risk pathologic features were defined as AJCC categories pT3 and pT4. In addition, AJCC OOTF Size Groups were defined as follows: (1) less than half, (2) more than half but less than two thirds, (3) more than two thirds of globe volume involved, and (4) diffuse infiltrating retinoblastoma.

MAIN OUTCOME MEASURES

Statistical risk of high-risk pathologic features corresponding to AJCC cT3 subcategories and AJCC OOTF Size Groups.

RESULTS

Of 942 retinoblastoma eyes treated by primary enucleation, 282 (30%) showed high-risk pathologic features. Both cT subcategories and AJCC OOTF Size Groups (P < 0.001 for both) were associated with high-risk pathologic features. On logistic regression analysis, cT3c (iris neovascularization with glaucoma), cT3d (intraocular hemorrhage), and cT3e (aseptic orbital cellulitis) were predictive factors for high-risk pathologic features when compared with cT2a with an odds ratio of 2.3 (P = 0.002), 2.5 (P = 0.002), and 3.3 (P = 0.019), respectively. Size Group 3 (more than two-thirds globe volume) and 4 (diffuse infiltrative retinoblastoma) were the best predictive factors with an odds ratio of 3.3 and 4.1 (P < 0.001 for both), respectively, for high-risk pathologic features when compared with Size Groups 1 (i.e., < 50% of globe volume).

CONCLUSIONS

The AJCC retinoblastoma staging clinical cT3c-e subcategories (glaucoma, intraocular hemorrhage, and aseptic orbital cellulitis, respectively) as well as the AJCC OOTF Size Groups 3 (tumor more than two thirds of globe volume) and 4 (diffuse infiltrative retinoblastoma) both allowed stratification of clinical risk factors that can be used to predict the presence of high-risk pathologic features and thus facilitate treatment decisions.

MRI can reliably differentiate optic nerve inflammation from tumor invasion in retinoblastoma with orbital cellulitis

OBJECTIVE

To investigate prevalence and MRI phenotype of retinoblastoma-associated orbital cellulitis. Additionally, this study aimed to identify postlaminar optic nerve enhancement patterns differentiating between inflammation and tumor invasion.

DESIGN

A monocenter cohort study assessed the prevalence of orbital cellulitis features on MRI in retinoblastoma patients. A multicenter case-control study compared MRI features of the retinoblastoma-associated orbital cellulitis cases with retinoblastoma controls.

SUBJECTS

A consecutive retinoblastoma patient cohort of 236 patients (311 eyes) was retrospectively investigated. Subsequently, 30 retinoblastoma cases with orbital cellulitis were compared with 30 matched retinoblastoma controls without cellulitis.

METHODS

In the cohort study, retinoblastoma MRI scans were scored on presence of inflammatory features. In the case-control study MRI scans were scored on intraocular features and postlaminar optic nerve enhancement patterns. Postlaminar enhancement patterns were compared with histopathologic assessment of postlaminar tumor invasion. Interreader agreement was assessed and exact tests with Bonferroni-correction were adopted for statistical comparisons.

MAIN OUTCOME MEASURES

Prevalence of retinoblastoma-associated orbital cellulitis on MRI was calculated. Frequency of intra-ocular MRI features were compared between orbital cellulitis cases and controls. Sensitivity and specificity of postlaminar optic nerve patterns for detection of postlaminar tumor invasion was assessed.

RESULTS

The MRI prevalence of retinoblastoma-associated orbital cellulitis was 6.8% (16/236). Retinoblastoma with orbital cellulitis showed significantly more tumor necrosis, uveal abnormalities (inflammation, hemorrhage and necrosis), lens luxation (all P < 0.001), and a larger eye size (P = 0.012). The inflammatory pattern of optic nerve enhancement (strong enhancement similar to adjacent choroid) was solely found in orbital cellulitis cases, of which none (0/16) showed tumor invasion on histopathology. Of patients with invasive pattern enhancement, 50% (5/10) showed tumor invasion on histopathology. Considering these different enhancement patterns, i.e. suggestive for either inflammation or tumor invasion, increased specificity for detection of postlaminar tumor invasion within the context of orbital cellulitis from 32% (95%CI:16-52%) to 89% (95%CI:72-98%).

CONCLUSIONS

Retinoblastoma cases presenting with orbital cellulitis show MRI findings of a larger eye size, extensive tumor necrosis, uveal abnormalities, and lens luxation. MRI contrast enhancement patterns within the postlaminar optic nerve can differentiate between tumor invasion and inflammatory changes.

MRI-based radiomics model can improve the predictive performance of postlaminar optic nerve invasion in retinoblastoma

OBJECTIVES

To develop an MRI-based radiomics model to predict postlaminar optic nerve invasion (PLONI) in retinoblastoma (RB) and compare its predictive performance with subjective radiologists' assessment.

METHODS

We retrospectively enrolled 124 patients with pathologically proven RB (90 in training set and 34 in validation set) who had MRI scans before surgery. A radiomics model for predicting PLONI was developed by extracting quantitative imaging features from axial T2W images and contrast-enhanced T1W images in the training set. The Kruskal-Wallis test, least absolute shrinkage and selection operator regression, and recursive feature elimination were used for feature selection, where upon a radiomics model was built with a logistic regression (LR) classifier. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve and the accuracy were assessed to evaluate the predictive performance in the training and validation set. The performance of the radiomics model was compared to radiologists' assessment by DeLong test.

RESULTS

The AUC of the radiomics model for the prediction of PLONI was 0.928 in the training set and 0.841 in the validation set. Radiomics model produced better sensitivity than radiologists' assessment (81.1% vs  43.2% in training set, 82.4vs 52.9% in validation set). In all 124 patients, the AUC of the radiomics model was 0.897, while that of radiologists' assessment was 0.674 (p < 0.001, DeLong test).

CONCLUSION

MRI-based radiomics model to predict PLONI in RB patients was shown to be superior to visual assessment with improved sensitivity and AUC, and may serve as a potential tool to guide personalized treatment.

Monitoring Retinoblastoma by Machine Learning of Aqueous Humor Metabolic Fingerprinting

The most common intraocular pediatric malignancy, retinoblastoma (RB), accounts for ≈10% of cancer in children. Efficient monitoring can enhance living quality of patients and 5-year survival ratio of RB up to 95%. However, RB monitoring is still insufficient in regions with limited resources and the mortality may even reach over 70% in such areas. Here, an RB monitoring platform by machine learning of aqueous humor metabolic fingerprinting (AH-MF) is developed, using nanoparticle enhanced laser desorption/ionization mass spectrometry (LDI MS). The direct AH-MF of RB free of sample pre-treatment is recorded, with both high reproducibility (coefficient of variation < 10%) and sensitivity (low to 0.3 pmol) at sample volume down to 40 nL only. Further, early and advanced RB patients with area-under-the-curve over 0.9 and accuracy over 80% are differentiated, through machine learning of AH-MF. Finally, a metabolic biomarker panel of 7 metabolites through accurate MS and tandem MS (MS/MS) with pathway analysis to monitor RB is identified. This work can contribute to advanced metabolic analysis of eye diseases including but not limited to RB and screening of new potential metabolic targets toward therapeutic intervention.

Aqueous seeding in retinoblastoma: Classification and clinicopathological correlation

PURPOSE

To correlate clinical types of aqueous seeds with histopathological characteristics in primarily enucleated eyes with retinoblastoma (RB).

DESIGN

Retrospective study PARTICIPANTS: Twenty-five patients with RB METHODS: Clinicopathological correlation of aqueous seeds in 25 eyes that underwent primary enucleation and had evidence of aqueous seeds MAIN OUTCOME MEASURES: Histopathological characteristics of aqueous seeds RESULTS: All 25 enucleated eyes were classified as group E RB based on International Classification of Intraocular Retinoblastoma. Clinically, type 1 aqueous seeds were noted in 9 (36%), type 2 in 8 (32%), and type 3 in 8 (32%). Based on histopathology, type 1 seeds were individual tumor cells admixed with macrophages and non-viable tumor cells; type 2 seeds were spheres and are classified into two subtypes a) Spheres without central necrosis containing solid clusters of tumor cells b) Spheres with central necrosis containing central core of necrotic cells surrounded by viable tumor cells; and type 3 seeds were tumor cells admixed with macrophages and RBCs that sediment into angle. Aqueous seeding involved both anterior (n=25; 100%) and posterior chambers (n=18; 72%). Significant intraocular tissue (Schlemm's canal, trabecular meshwork, ciliary body, choroid, optic nerve, sclera) infiltration of RB was noted in 23 (92%) cases. Compared to type 1 and 2 seeds, patients with type 3 seeds were more commonly associated with ciliary body infiltration (41% vs 88%; p=0.04). Over a mean follow-up period of 57 months (median, 49 months; range, <1 to 175 months), metastasis and death was noted in 3 (12%) patients.

CONCLUSION

Similar to vitreous seeds in RB, aqueous seeds have three distinct histopathological types. Posterior chamber seeds are noted in 72% cases presenting with anterior chamber seeds indicating the need for treatment of both the chambers whenever conservative treatment is attempted in suitable cases. Most (92%) cases with primary aqueous seeding are associated with other high-risk histopathology features, suggesting a cautious approach for conservative management in these cases.

Publication Trends of Research on Retinoblastoma During 2001-2021: A 20-Year Bibliometric Analysis

Background: Retinoblastoma is the most common primary intraocular malignancy of childhood. Despite high survival and eye salvage as the result of various types of therapies, retinoblastoma remains a disease that places a considerable burden on developing countries. Our study attempted to analyse the research trends in retinoblastoma research and compare contributions from different countries, institutions, journals, and authors.

Methods: We extracted all publications concerning retinoblastoma from 2001 to 2021 from the Web of Science database. Microsoft Excel and VOSviewer were employed to collect publication data, analyse publication trends, and visualize relevant results.

Results: A total of 1,675 publications with 30,148 citations were identified. The United States contributed the most publications (643) and citations (16,931 times) with the highest H-index value (67) as of February 4, 2021. China ranked second in the number of publications (259), while ranking fourth in both citations (2,632 times) and the H-index (26) ranked fourth. The British Journal of Ophthalmology was the most productive journal concerning retinoblastoma, and Abramson DH had published the most papers in the field. Keywords were categorized into three clusters; tumor-related research, clinical research, and management-related research. The keywords “intravitreal,” “intraarterial,” and “intravenous” appeared the most frequently, with the average appearing year being 2018.1, 2017.7, and 2017.1, respectively. Management-related research has been recognized as a heavily researched topic in the field.

Conclusion: We conclude that the United States, China, and India made the most exceptional contributions in the field of retinoblastoma research, while China still has a disparity between the quantity and quality of publications. Management-related research, including intravitreal, intraarterial, and intravenous chemotherapy was considered as a potential focus for future research.

Accuracy of Computed Tomography and Magnetic Resonance Imaging for Detection of Pathologic Risk Factors in Patients Diagnosed with Retinoblastoma

Aim: To assess and compare the diagnostic accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) for detecting the extent of tumor invasion in eyes with advanced retinoblastoma prior to enucleation using histopathologic analysis as a reference.Methods: A total of 56 patients (68 eyes) enucleated for retinoblastoma were reviewed. Eyes with complete data (CT 28, MRI 16) were included for analysis. Imaging data were reviewed by a pediatric radiologist, blinded to histopathology results. Four high-risk factors which included scleral, choroidal, anterior eye segment invasion, and postlaminar optic nerve invasion were assessed.Results: For CT, the diagnostic odds ratio (DOR), sensitivity, and specificity for detecting postlaminar optic nerve invasion were 1.7%, 25%, and 83.3%. Choroidal invasion was correctly identified in only 2 of 10 eyes (DOR 0.5, sensitivity 20%, specificity 66.7%). For scleral invasion, CT showed a diagnostic ratio of 1.5%, sensitivity 40%, specificity 69.6% whereas for anterior segment invasion DOR was 9.2%, sensitivity 100%, and specificity 65.4%. MRI showed a higher DOR for detecting postlaminar optic nerve invasion of 39%, sensitivity 77.8%, and specificity 100%. Choroidal and scleral invasion on MRI had a DOR of 6.5% (sensitivity 25%, specificity 100%) and 6% (sensitivity 33.3%, specificity 92.3%) respectively while DOR for anterior segment invasion was 1.3% (sensitivity 50%, specificity 57.1%).Conclusion: CT showed a poor diagnostic accuracy for all four high-risk factors in advanced retinoblastoma and therefore may not be a useful tool for assessment of tumor extension. For MRI, detection of postlaminar optic nerve invasion was moderately accurate although less accurate for detection of other risk factors. Decision-making for each child should not be based on any single parameter but rather on consideration of clinical factors in combination with radiologic findings.

Neonatal Retinoblastoma

Retinoblastoma is the most common ocular malignancy of childhood. With an estimated 300 cases annually in the United States, retinoblastoma is nevertheless considered a rare tumor. Although retinoblastoma primarily affects younger children, diagnosis during the neonatal age range is less common. However, an understanding of patients at risk is critical for appropriate screening. Early detection and treatment by a multidisciplinary specialty team maximizes the chance for survival and ocular/vision salvage while minimizing treatment-related toxicity. Testing for alterations in the RB1 gene has become standard practice, and informs screening and genetic counseling recommendations for patients and their families.

Retinoblastoma: What the Neuroradiologist Needs to Know

Retinoblastoma is the most common primary intraocular tumor of childhood. Accurate diagnosis at an early stage is important to maximize patient survival, globe salvage, and visual acuity. Management of retinoblastoma is individualized based on the presenting clinical and imaging features of the tumor, and a multidisciplinary team is required to optimize patient outcomes. The neuroradiologist is a key member of the retinoblastoma care team and should be familiar with characteristic diagnostic and prognostic imaging features of this disease. Furthermore, with the adoption of intra-arterial chemotherapy as a standard of care option for globe salvage therapy in many centers, the interventional neuroradiologist may play an active role in retinoblastoma treatment. In this review, we discuss the clinical presentation of retinoblastoma, ophthalmic imaging modalities, neuroradiology imaging features, and current treatment options.

Diagnostic performance of MRI of post-laminar optic nerve invasion detection in retinoblastoma: A systematic review and meta-analysis

PURPOSE

Preoperative MRI detection of post-laminar optic nerve invasion (PLONI) offers guidance in assessing the probability of total tumor resection, an estimation of the extent of surgery, and screening of candidates for eye-preserving therapies or neoadjuvant chemotherapies in the patients with retinoblastoma (RB). The purpose of this systematic review and meta-analysis was to evaluate the diagnostic performance of MRI for detecting PLONI in patients with RB and to demonstrate the factors that may influence the diagnostic performance.

METHODS

Ovid-MEDLINE and EMBASE databases were searched up to January 11, 2020, for studies identifying the diagnostic performance of MRI for detecting PLONI in patients with RB. The pooled sensitivity and specificity of all studies were calculated followed by meta-regression analysis.

RESULTS

Twelve (1240 patients, 1255 enucleated globes) studies were included. The pooled sensitivity was 61%, and the pooled specificity was 88%. Higgins I² statistic demonstrated moderate heterogeneity in the sensitivity (I² = 72.23%) and specificity (I² = 78.11%). Spearman correlation coefficient indicated the presence of a threshold effect. In the meta-regression, higher magnetic field strength (3 T than 1.5 T), performing fat suppression, and thinner slice thickness (< 3 mm) were factors causing heterogeneity and enhancing diagnostic power across the included studies.

CONCLUSIONS

MR imaging was demonstrated to have acceptable diagnostic performance in detecting PLONI in patients with RB. The variation in the magnetic field strength and protocols was the main factor behind the heterogeneity across the included studies. Therefore, there is room for developing and optimizing the MR protocols for patients with RB.

Evaluation of the role of ultrasound biomicroscopy in advanced retinoblastoma: A prospective study on Asian Indian children

Aim: To evaluate the role of ultrasound biomicroscopy (UBM) in retinoblastoma (RB).Methods: Children with advanced unilateral RB were included. UBM was performed to look for tumour invasion into the anterior segment (AS) and for evaluation of quantitative parameters. Enucleation was done and UBM findings were correlated with histopathology. The main outcome measures were sensitivity and specificity of UBM for detecting AS invasion and comparison of quantitative parameters between the tumour affected and fellow eyes.Results: Fifty patients were evaluated. The mean age was 2.76 ± 1.63 years. Enucleation was performed in 50 eyes. The sensitivity and specificity of UBM for AS invasion were 80% (95% CI, 44-97%) and 95% (95% CI, 83-99%), respectively. UBM showed a sensitivity and specificity of 100% (95% CI, 59-100%) and 95% (95% CI, 84-99%), respectively, for iris invasion, 88% (95% CI, 47-100%) and 100% (95% CI, 92-100%), respectively, for ciliary body invasion, and 63% (95% CI, 24-91%) and 100% (95% CI, 92-100%), respectively, for anterior chamber (AC) angle invasion. Quantitative parameters were studied in 100 eyes. As compared to the fellow eyes, the AC angle was narrow (p < 0.05), posterior chamber was shallow (p = 0.004) and zonular length was increased (p = 0.001) in RB eyes.Conclusion: This clinicopathological study provides valuable insights into the role of UBM for evaluation of anterior extension of RB and for assessment of architectural changes in the AS due to the tumour.

Full-width postlaminar optic nerve tumor invasion of retinoblastoma as risk-factor for leptomeningeal spread of retinoblastoma. A case report and review of the literature

We present a 6-year-old boy with unilateral retinoblastoma of the left eye. MRI showed an intraocular tumor that extended into the optic nerve beyond the lamina cribrosa. The affected eye was enucleated and the optic nerve resection margin proved to be free. Following protocol, this patient received six courses of adjuvant systemic chemotherapy. Unfortunately, after 5 months this patient returned with the leptomeningeal spread of the tumor and died quickly thereafter.Histopathologic analysis of the enucleated eye and distal optic nerve revealed that the postlaminar tumor cells occupied the entire width of the optic nerve, extending all the way up to the pia mater, whereas, more often the tumor invasion is restricted to the center of the optic nerve. This was also visible on the MR images where contrast enhancement occupied the entire nerve width. A resection margin with tumor cells is recognized as a risk factor for metastasis, but perhaps the proximity of tumor cells to the leptomeninges should also be judged with caution as a potential increased risk for metastatic spread.

Diagnosis of Postlaminar Optic Nerve Invasion in Retinoblastoma With MRI Features

BACKGROUND

Retinoblastomas (RBs) with postlaminar optic nerve invasion (PLONI) increases the risk of local recurrence or systemic metastasis. Most MRI studies on PLONI focused on optic nerve enhancement and tumor size, with reported relatively high specificity (84-98%) but low sensitivity (37-78%), which shows room for improvement, especially with regard to sensitivity.

PURPOSE

To evaluate the diagnostic performance for detecting PLONI with RB using MRI features.

STUDY TYPE

Retrospective.

POPULATION

Fifty patients with histopathologic PLONI and 70 patients without PLONI of RB.

FIELD STRENGTH/SEQUENCE

1.5T and 3.0T, precontrast axial T₁ -weighted and T₂ -weighted, postcontrast axial, coronal and oblique-sagittal T₁ -weighted.

ASSESSMENT

The eyes were histopathologically analyzed and the preoperative MRI features of the eyes were independently evaluated by three observers.

STATISTICAL TESTS

MRI features suggesting the presence of PLONI were identified by univariate and multivariable analysis. Receiver operating characteristic curve (ROC) and the area under the curve (AUC) were used to analyze diagnostic performance.

RESULTS

Significant independent diagnostic factors for PLONI include: 1: Bilateral tumor (odds ratio [OR], 15.32; 95% confidence interval [CI]: 1.63-143.51); 2: Tumor with total coverage of the optic disk (OR, 6.43; 95% CI: 1.04-39.79); and 3: Optic nerve enhancement (OR, 8.43; 95% CI: 3.50-20.31). On the other hand, isointense signal of tumor on T₂ WI (OR, 0.30; 95% CI: 0.12-0.75) was an independent diagnostic factor in excluding PLONI. ROC analysis showed AUC of 0.84 (95% CI: 0.77-0.91, P < 0.0001) for PLONI. Based on the cutoff of maximum Youden index, the sensitivity, specificity, and accuracy were 82%, 73%, and 77%, respectively.

DATA CONCLUSION

MRI features of RB showed a strong association with PLONI. The model of MRI features demonstrated promising diagnostic performance in detecting PLONI.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1045-1052.

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.

Blood Flow in Monocular Retinoblastoma Assessed by Color Doppler and Correlations With High-Risk Pathologic Features

Purpose

To use color Doppler to analyze blood flow in the retrobulbar central retinal artery (CRA) and central retinal vein (CRV) in monocular retinoblastoma.

Methods

This prospective study included patients with group D and E retinoblastomas managed with only enucleation. Peak blood velocities were assessed in the CRA and CRV of tumor-containing eyes (CRAv and CRVv, respectively). The resistivity index in the CRA (RIa) and pulse index in the CRV (PIv) were calculated and related to optic nerve invasion (ONi), choroid invasion (mCHi), and tumor volume. RIa and PIv were also calculated for healthy eyes.

Results

In total, 25 patients with a mean age of 30.8-months old were included. The means (SD) for CRAv, CRVv, RIa, and PIv were 26.94 (12.32) cm/s, 16.2 (9.56) cm/s, 0.88 (0.12) and 0.79 (0.29), respectively. Tumor volume was significantly correlated with CRAv (P = 0.025) and RIa (P = 0.032). ONi was present in 19 eyes and correlated with a smaller PIv (P < 0.001). A PIv less than 0.935 had a sensitivity of 89.5% and specificity of 83.3% for predicting ONi. mCHi was not correlated with flow values. Healthy eyes had a significantly lower RIa (P < 0.001) and lower PIv than eyes with (P = 0.009) and without (P < 0.001) ONi.

Conclusions

In advanced-stage monocular retinoblastoma, tumor volume was directly correlated with CRAv and RIa, and lower PIv was correlated with optic nerve invasion when a predictive cut-off value of less than 0.935 was applied. Comparisons with healthy eyes showed that tumor-containing eyes were associated with higher RIa and PIv values.

Magnetic resonance imaging for tumor restaging after chemotherapy in retinoblastoma with optic nerve invasion

PURPOSE

Extraocular retinoblastoma with optic nerve invasion is treated by a multimodal protocol consisting of neoadjuvant chemotherapy, enucleation, and adjuvant therapy. This study was conducted to evaluate the performance of magnetic resonance imaging (MRI) used for tumor restaging in these children after systemic chemotherapy administration.

METHODS

Contrast-enhanced MRI scan of orbits and brain was performed at diagnosis and patients were treated with neoadjuvant chemotherapy. After chemotherapy, MRI scan was repeated for tumor restaging and residual post-laminar thickening and/or enhancement of the affected optic nerve, if any, was recorded. MRI findings were correlated with histopathology in enucleated specimens. The main outcome measures were specificity, sensitivity, and accuracy of MRI in predicting post-laminar invasion after neoadjuvant chemotherapy.

RESULTS

A total of 46 eyes (46 patients) were studied. Optic nerve thickening on MRI had a sensitivity, specificity, and accuracy of 100% (95% Confidence Interval (CI): 64.6-100%), 76.9% (95% CI: 61.7-87.4%), and 80.4% (95% CI: 66.8-89.4%), respectively. Optic nerve enhancement had a sensitivity, specificity, and accuracy of 85.7% (95% CI: 48.7-97.4%), 79.5 % (95% CI: 64.5-89.2%), and 80.4% (95% CI: 66.8-89.4%), respectively. Combined thickening and enhancement of the optic nerve had a sensitivity, specificity, and accuracy of 100% (95% CI: 60.9-100%), 82.4% (95% CI: 66.5-91.7%), and 85% (95% CI: 70.9-92.9%), respectively.

CONCLUSION

MRI is a valuable tool for restaging of retinoblastoma and predicting residual optic nerve disease after neoadjuvant chemotherapy. Combined thickening and enhancement on MRI appeared to be a more reliable indicator of post-laminar invasion as compared to thickening or enhancement alone.

MR Imaging Features of Retinoblastoma: Association with Gene Expression Profiles

Purpose To identify associations between magnetic resonance (MR) imaging features and gene expression in retinoblastoma. Materials and Methods A retinoblastoma MR imaging atlas was validated by using anonymized MR images from referral centers in Essen, Germany, and Paris, France. Images were from 39 patients with retinoblastoma (16 male and 18 female patients [the sex in five patients was unknown]; age range, 5-90 months; inclusion criterion: pretreatment MR imaging). This atlas was used to compare MR imaging features with genome-wide messenger RNA (mRNA) expression data from 60 consecutive patients obtained from 1995 to 2012 (35 male patients [58%]; age range, 2-69 months; inclusion criteria: pretreatment MR imaging, genome-wide mRNA expression data available). Imaging pathway associations were analyzed by means of gene enrichment. In addition, imaging features were compared with a predefined gene expression signature of photoreceptorness. Statistical analysis was performed with generalized linear modeling of radiology traits on normalized log2-transformed expression values. P values were corrected for multiple hypothesis testing. Results Radiogenomic analysis revealed 1336 differentially expressed genes for qualitative imaging features (threshold P = .05 after multiple hypothesis correction). Loss of photoreceptorness gene expression correlated with advanced stage imaging features, including multiple lesions (P = .03) and greater eye size (P < .001). The number of lesions on MR images was associated with expression of MYCN (P = .04). A newly defined radiophenotype of diffuse-growing, plaque-shaped, multifocal tumors displayed overexpression of SERTAD3 (P = .003, P = .049, and P = .06, respectively), a protein that stimulates cell growth by activating the E2F network. Conclusion Radiogenomic biomarkers can potentially help predict molecular features, such as photoreceptorness loss, that indicate tumor progression. Results imply a possible role for radiogenomics in future staging and treatment decision making in retinoblastoma.

Retinoblastoma for Pediatric Ophthalmologists

Retinoblastoma can present in 1 or both eyes and is the most common intraocular malignancy in childhood. It is typically initiated by biallelic mutation of the RB1 tumor suppressor gene, leading to malignant transformation of primitive retinal cells. The most common presentation is leukocoria, followed by strabismus. Heritable retinoblastoma accounts for 45% of all cases, with 80% being bilateral. Treatment and prognosis of retinoblastoma is dictated by the disease stage at initial presentation. The 8th Edition American Joint Committee on Cancer (AJCC) TNMH (tumor, node, metastasis, heritable trait) staging system defines evidence-based clinical and pathological staging for overall prognosis for eye(s) and child. Multiple treatment options are available in 2018 for retinoblastoma management with a multidisciplinary team, including pediatric ocular oncology, medical oncology, radiation oncology, genetics, nursing, and social work. Survival exceeds 95% when disease is diagnosed early and treated in centers specializing in retinoblastoma. However, survival rates are less than 50% with extraocular tumor dissemination. We summarize the epidemiology, genetics, prenatal screening, diagnosis, classification, investigations, and current therapeutic options in the management of retinoblastoma.

The value of MRI in evaluating the efficacy and complications with the treatment of intra-arterial chemotherapy for retinoblastoma

Retinoblastoma is the most common intraocular malignant tumor of childhood. Intra-arterial chemotherapy (IAC) is a recently popularized technique used for the treatment of retinoblastoma, to decrease mortality, increase preservation of the eye, and prevent blindness. Along with the extensive use of IAC, it is important to apply noninvasive examination methods to assess the activity of the tumor and the risk factors for disease dissemination without histopathological confirmation. There are few studies that have assessed the value of magnetic resonance imaging (MRI) in evaluating the efficacy and complications of IAC for retinoblastoma. We retrospectively analyzed the MRI features of 60 patients with unilateral retinoblastoma given the primary treatment of IAC from January 2014 to February 2016 in our hospital. Our study showed that MRI could well assess the decreased activity of the tumor after IAC, presenting with diminished tumor size, increased apparent diffusion coefficient (ADC) values (from 0.94 ± 0.24 × 10-3 mm2/s to 2.24 ± 0.40 × 10-3 mm2/s), and a reduced degree of enhancement of the tumor. Our study also showed that MRI can monitor the risk factors of abnormal enhancement of the postlaminar optic nerve, to avoid unnecessary enucleation. Meanwhile, the results showed that the main late complications after IAC included affected eyeball volume reduction, subretinal hemorrhage, vitreous hemorrhage, vitreous opacity, cataractous len, and choroidal vascular ischemia.

9.4T and 17.6T MRI of Retinoblastoma: Ex Vivo evaluation of microstructural anatomy and disease extent compared with histopathology

BACKGROUND

Retinoblastoma is the most common intraocular tumor in childhood with a good prognosis in terms of mortality, but detailed information about tumor morphology and disease extent in retinoblastoma is important for treatment decision making.

PURPOSE

To demonstrate ultrahigh-field MRI tumor morphology and tumor extent in retinoblastoma correlating with in and ex vivo images with histopathology.

STUDY TYPE

Prospective case series.

POPULATION

Six retinoblastoma patients (median age 5.5 months, range 2-14) were prospectively included in this study. Median time between diagnosis and enucleation was 8 days (range 7-19).

FIELD STRENGTH/SEQUENCE

In vivo pre-enucleation at 1.5T MRI with a circular surface coil. Ex vivo imaging (FLASH T₁ -weighted and RARE T₂ -weighted) was performed at field strengths of 9.4T and 17.6T.

ASSESSMENT

After ex vivo imaging, the eyes were histopathologically analyzed and morphologically matched with MRI findings by three authors (two with respectively 14 and 4 years of experience in ocular MRI and one with 16 years of experience in ophthalmopathology).

RESULTS

Small submillimeter morphological aspects of intraocular retinoblastoma were successfully depicted with higher-resolution MRI and matched with histopathology images. With ex vivo MRI a small subretinal tumor seed (300 μm) adjacent to the choroid was morphologically matched with histopathology. Also, a characteristic geographical pattern of vital tumor tissue (400 μm) surrounding a central vessel interspersed with necrotic areas correlated with histopathology images. Tumor invasion into the optic nerve showed a higher signal intensity on T₁ -weighted higher-resolution MRI.

DATA CONCLUSION

Higher-resolution MRI allows for small morphological aspects of intraocular retinoblastoma and extraocular disease extent not visible on currently used clinical in vivo MRI to be depicted.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1487-1497.

Correlation between conventional MR imaging combined with diffusion-weighted imaging and histopathologic findings in eyes primarily enucleated for advanced retinoblastoma: a retrospective study

OBJECTIVES

To determine the diagnostic accuracy of conventional MRI in detecting tumour invasion of advanced intraocular retinoblastoma and to correlate ADC values with high-risk prognostic parameters.

METHOD

The sensitivities, specificities, positive predictive values (PPV), negative predictive values (NPV) and accuracies of MRI in detecting tumour-extent parameters of 63 retinoblastomas were determined. Furthermore, ADC values were correlated with high-risk prognostic parameters.

RESULTS

MRI detected postlaminar optic nerve with a sensitivity of 73.3% (95% CI 44.9-92.2%) and a specificity of 89.6% (77.3-96.5%), while the specificity for choroidal invasion was only 31.8% (13.9-54.9%). Likewise, MRI failed to predicted early optic nerve invasion in terms of low sensitivity and PPV. In contrast, scleral and ciliary body invasion could be correctly excluded with high NPV. ADC values were significantly lower in patients with undifferentiated tumours, large tumour size, as with optic nerve and scleral invasion (all p < 0.05). However, no correlation was found between ADC values and the degree of choroidal or ciliary body infiltration. Additionally, ADC values were negatively correlated with Ki-67 index (r = -0.62, P = 0.002).

CONCLUSIONS

Conventional MRI has some limitations in reliably predicting microscopic infiltration, with the diagnostic efficiency showing room for improvement, whereas ADC values correlated well with certain high-risk prognostic parameters for retinoblastoma.

KEY POINTS

• Conventional MRI failed to predicted microscopic infiltration of the retinoblastoma. • Scleral and ciliary body invasion could be excluded with high NPV. • ADC values correlated well with some high-risk pathological prognostic parameters.

Update on Ophthalmic Oncology 2014: Retinoblastoma and Uveal Melanoma

PURPOSE

The aim of this study was to review peer-reviewed articles on ophthalmic oncology (specifically retinoblastoma and uveal melanoma) published from January to December 2014.

DESIGN

This study is a literature review.

METHODS

The terms retinoblastoma and uveal melanoma were used in a MEDLINE literature search. Abstracts were studied, and the most relevant articles were selected for inclusion and further in-depth review.

RESULTS

In retinoblastoma, more eyes are being salvaged due to intravitreal melphalan. The year 2014 marks a deepening in our understanding of the biological basis of the disease and the cell of origin. Knowledge on the genetic underpinnings of uveal melanoma has broadened to include other pathways, interactions, and potential therapeutic targets.

CONCLUSIONS

In 2014, there were valuable advancements in our knowledge of retinoblastoma and uveal melanoma. Some of these resulted in improved patient management.

Diagnostic Accuracy of Intraocular Tumor Size Measured with MR Imaging in the Prediction of Postlaminar Optic Nerve Invasion and Massive Choroidal Invasion of Retinoblastoma

Purpose To assess the correlation of intraocular retinoblastoma tumor size measured with magnetic resonance (MR) imaging in the prediction of histopathologically determined metastatic risk factors (postlaminar optic nerve invasion and massive choroidal invasion). Materials and Methods The ethics committee approved this retrospective multicenter study with a waiver of informed consent. The study population included 370 consecutive patients with retinoblastoma (375 eyes) who underwent baseline MR imaging, followed by primary enucleation from 1993 through 2014. Tumor sizes (maximum diameter and volume) were measured independently by two observers and correlated with histopathologic risk factors. Receiver operating characteristic curves were used to analyze the diagnostic accuracy of tumor size, and areas under the curve were calculated. Logistic regression analysis was performed to evaluate potential confounders. Results Receiver operating characteristic analysis of volume and diameter, respectively, yielded areas under the curve of 0.77 (95% confidence interval [CI]: 0.70, 0.85; P < .0001) and 0.78 (95% CI: 0.71, 0.85; P < .0001) for postlaminar optic nerve invasion (n = 375) and 0.67 (95% CI: 0.57, 0.77; P = .0020) and 0.70 (95% CI: 0.59, 0.80; P = .0004) for massive choroidal tumor invasion (n = 219). For the detection of co-occurring massive choroidal invasion and postlaminar optic nerve invasion (n = 219), volume and diameter showed areas under the curve of 0.81 (95% CI: 0.70, 0.91; P = .0032) and 0.83 (95% CI: 0.73, 0.93; P = .0016), respectively. Conclusion Intraocular tumor size shows a strong association with postlaminar optic nerve invasion and a moderate association with massive choroidal invasion. These findings provide diagnostic accuracy measures at different size cutoff levels, which could potentially be useful in a clinical setting, especially within the scope of the increasing use of eye-salvage treatment strategies. (©) RSNA, 2015 Online supplemental material is available for this article.

Blood flow velocity in monocular retinoblastoma assessed by color Doppler

OBJECTIVE

To analyze the flow of retrobulbar vessels in retinoblastoma by color Doppler imaging.

METHODS

A prospective study of monocular retinoblastoma treated by enucleation between 2010 and 2014. The examination comprised fundoscopy, magnetic resonance imaging, ultrasonography and color Doppler imaging. The peak blood velocities in the central retinal artery and central retinal vein of tumor-containing eyes (tuCRAv and tuCRVv, respectively) were assessed. The velocities were compared with those for normal eyes (nlCRAv and nlCRVv) and correlated with clinical and pathological findings. Tumor dimensions in the pathological sections were compared with those in magnetic resonance imaging and ultrasonography and were correlated with tuCRAv and tuCRVv. In tumor-containing eyes, the resistivity index in the central retinal artery and the pulse index in the central retinal vein were studied in relation to all variables.

RESULTS

Eighteen patients were included. Comparisons between tuCRAv and nlCRAv and between tuCRVv and nlCRVv revealed higher velocities in tumor-containing eyes (p < 0.001 for both), with a greater effect in the central retinal artery than in the central retinal vein (p = 0.024). Magnetic resonance imaging and ultrasonography measurements were as reliable as pathology assessments (p = 0.675 and p = 0.375, respectively). A positive relationship was found between tuCRAv and the tumor volume (p = 0.027). The pulse index in the central retinal vein was lower in male patients (p = 0.017) and in eyes with optic nerve invasion (p = 0.0088).

CONCLUSIONS

TuCRAv and tuCRVv are higher in tumor-containing eyes than in normal eyes. Magnetic resonance imaging and ultrasonography measurements are reliable. The tumor volume is correlated with a higher tuCRAv and a reduced pulse in the central retinal vein is correlated with male sex and optic nerve invasion.

MRI helps depict clinically undetectable risk factors in advanced stage retinoblastomas

This study compared high-resolution MRI with histology in advanced stage retinoblastomas in which ophthalmoscopy and ultrasonography did not give an exhaustive depiction of the tumour and/or its extension. MRI of orbits and head in 28 retinoblastoma patients (28 eyes) treated with primary enucleation were evaluated. Iris neoangiogenesis, infiltrations of optic nerve, choroid, anterior segment and sclera suspected at MR and histology were compared. Abnormal anterior segment enhancement (AASE) was also correlated with histologically proven infiltrations. Brain images were also evaluated. Significant values were obtained for: prelaminar optic nerve (ON) sensitivity (0.88), positive predictive value (PPV) (0.75) and negative predictive value (NPV) (0.71); post-laminar ON sensitivity (0.50), specificity (0.83), PPV (0.50) and NPV (0.83); overall choroid sensitivity (0.82), and massive choroid NPV (0.69); scleral specificity (1), and NPV (1). AASE correlated with iris neoangiogenesis in 14 out of 19 eyes, and showed significant values for: overall ON PPV (0.65), prelaminar ON sensitivity (0.65), and PPV (0.61), post-laminar ON NPV (0.64); overall choroid sensitivity (0.77), PPV (0.59) and NPV (0.73); scleral NPV (0.83); anterior segment sensitivity (1), and NPV (1). Odds ratios (OR) and accuracy were significant in scleral and prelaminar optic nerve infiltration. Brain examination was unremarkable in all cases. High-resolution MRI may add important findings to clinical evaluation of advanced stage retinoblastomas.

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.

Retinoblastoma

Retinoblastoma is a rare cancer of the infant retina that is diagnosed in approximately 8,000 children each year worldwide. It forms when both retinoblastoma gene (RB1) alleles are mutated in a susceptible retinal cell, probably a cone photoreceptor precursor. Loss of the tumour-suppressive functions of the retinoblastoma protein (pRB) leads to uncontrolled cell division and recurrent genomic changes during tumour progression. Although pRB is expressed in almost all tissues, cone precursors have biochemical and molecular features that may sensitize them to RB1 loss and enable tumorigenesis. Patient survival is >95% in high-income countries but <30% globally. However, outcomes are improving owing to increased disease awareness for earlier diagnosis, application of new guidelines and sharing of expertise. Intra-arterial and intravitreal chemotherapy have emerged as promising methods to salvage eyes that with conventional treatment might have been lost. Ongoing international collaborations will replace the multiple different classifications of eye involvement with standardized definitions to consistently assess the eligibility, efficacy and safety of treatment options. Life-long follow-up is warranted, as survivors of heritable retinoblastoma are at risk for developing second cancers. Defining the molecular consequences of RB1 loss in diverse tissues may open new avenues for treatment and prevention of retinoblastoma, as well as second cancers, in patients with germline RB1 mutations.

Automatic Segmentation of the Eye in 3D Magnetic Resonance Imaging: A Novel Statistical Shape Model for Treatment Planning of Retinoblastoma

PURPOSE

Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes.

METHODS AND MATERIALS

Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error.

RESULTS

We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye.

CONCLUSION

We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.

Common pediatric head and neck congenital/developmental anomalies

Pediatric head and neck neuroradiology is a broad and complex topic. This article focuses on several of the common and sometimes challenging pediatric head and neck congenital/developmental anomalies physicians may encounter in clinical practice. Although some diagnoses may be evident on physical examination, others may present a diagnostic dilemma. Patients may initially present with a variety of secondary findings. Imaging serves an important role in making a diagnosis, guiding referral, and in some cases even providing treatment options through interventional radiology. Key diagnostic criteria and critical points of interest for each diagnosis are presented.

Assessment of early-stage optic nerve invasion in retinoblastoma using high-resolution 1.5 Tesla MRI with surface coils: a multicentre, prospective accuracy study with histopathological correlation

OBJECTIVES

To assess the accuracy of high-resolution (HR) magnetic resonance imaging (MRI) in diagnosing early-stage optic nerve (ON) invasion in a retinoblastoma cohort.

METHODS

This IRB-approved, prospective multicenter study included 95 patients (55 boys, 40 girls; mean age, 29 months). 1.5-T MRI was performed using surface coils before enucleation, including spin-echo unenhanced and contrast-enhanced (CE) T1-weighted sequences (slice thickness, 2 mm; pixel size <0.3 × 0.3 mm(2)). Images were read by five neuroradiologists blinded to histopathologic findings. ROC curves were constructed with AUC assessment using a bootstrap method.

RESULTS

Histopathology identified 41 eyes without ON invasion and 25 with prelaminar, 18 with intralaminar and 12 with postlaminar invasion. All but one were postoperatively classified as stage I by the International Retinoblastoma Staging System. The accuracy of CE-T1 sequences in identifying ON invasion was limited (AUC = 0.64; 95 % CI, 0.55 - 0.72) and not confirmed for postlaminar invasion diagnosis (AUC = 0.64; 95 % CI, 0.47 - 0.82); high specificities (range, 0.64 - 1) and negative predictive values (range, 0.81 - 0.97) were confirmed.

CONCLUSION

HR-MRI with surface coils is recommended to appropriately select retinoblastoma patients eligible for primary enucleation without the risk of IRSS stage II but cannot substitute for pathology in differentiating the first degrees of ON invasion.

KEY POINTS

• HR-MRI excludes advanced optic nerve invasion with high negative predictive value. • HR-MRI accurately selects patients eligible for primary enucleation. • Diagnosis of early stages of optic nerve invasion still relies on pathology. • Several physiological MR patterns may mimic optic nerve invasion.