Diagnostic image quality of gadolinium-enhanced T1-weighted MRI with and without fat saturation in children with retinoblastoma

[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.

Guidelines for magnetic resonance imaging in pediatric head and neck pathologies: a multicentre international consensus paper

The use of standardized imaging protocols is paramount in order to facilitate comparable, reproducible images and, consequently, to optimize patient care. Standardized MR protocols are lacking when studying head and neck pathologies in the pediatric population. We propose an international, multicenter consensus paper focused on providing the best combination of acquisition time/technical requirements and image quality. Distinct protocols for different regions of the head and neck and, in some cases, for specific pathologies or clinical indications are recommended. This white paper is endorsed by several international scientific societies and it is the result of discussion, in consensus, among experts in pediatric head and neck imaging.

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.

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.

[Retinoblastoma]

Retinoblastomas represent 6% of all malignant tumors in children under 5 years old, which untreated lead to blindness in the affected eye and death due to metastases. The main symptoms are leukocoria and strabismus, which if possible, always necessitate a clarification within 1 week for exclusion of a retinoblastoma. The most frequent differential diagnoses are Coats' disease and persistent fetal vasculature (PFV) as well as other intraocular tumors, in particular astrocytomas. Systemic chemotherapy, if necessary in combination with laser hyperthermia, local chemotherapy and brachytherapy are the most important methods for eye-preserving treatment. Advanced cases mostly necessitate enucleation.

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.

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.

Three presentations of CNS disease in patients with intraocular retinoblastoma at a tertiary medical center in the United States

BACKGROUND

Patients with intraocular retinoblastoma who present with central nervous (CNS) disease at diagnosis is very rare in developed countries.

METHODS

Herein, we report a review of patients with intraocular retinoblastoma diagnosed with concurrent CNS disease in the United States between January 2011 and June 2013.

RESULTS

Three patients were identified in this review. The first case is a 2-year old male who presented with unilateral Group E retinoblastoma, optic nerve infiltration to the orbital apex, and a suprasellar mass. The second case is a 5-month old female with bilateral retinoblastoma, who had no optic nerve invasion, but demonstrated a temporal lobe lesion that was biopsy-proven to be metastatic retinoblastoma. The third case is a 10-month old girl with bilateral retinoblastoma who presented with a sellar mass and no evidence of optic nerve invasion in the enucleated Group E eye.

CONCLUSIONS

Although rare in developed countries, patients with intraocular retinoblastoma can present with a spectrum of CNS findings at the time of diagnosis. Magnetic resonance imaging of the brain and orbits is a critical component of the staging evaluation.

Clinical Significance of Optic Nerve Enhancement on Magnetic Resonance Imaging in Enucleated Retinoblastoma Patients

PURPOSE

The aim of this 8-year retrospective review was to determine the clinical significance of gadolinium-enhanced magnetic resonance imaging (MRI) findings in retinoblastoma patients after enucleation, particularly the presence of abnormal contrast enhancement of the transected optic nerve.

DESIGN

Retrospective chart review.

SUBJECTS

A review was done on 88 patients with retinoblastoma undergoing 90 enucleations between January 2008 and December 2015.

METHODS

These patients underwent 233 MRI scans: 90 preoperative and 143 postoperative that were included for review.

MAIN OUTCOME MEASURE

The primary outcome measure assessed was abnormal MRI findings in the preoperative and postoperative MRI scans, specifically enhancement of the optic nerve and correlations between abnormal MRI findings and clinical outcomes for the 88 patients.

RESULTS

On the preoperative MRI, 4 optic nerves out of 90 scans showed positive enhancement. Fifty orbits had ≥1 postoperative MRI. Overall, 41 of 50 orbits (82%) of enucleated patients demonstrated postoperative contrast enhancement on MRI after enucleation, at a mean interval of 10 months after surgery. The percentage of MRI scans with optic nerve enhancement was 77% from 0 to 6 months after enucleation and 68% at >24 months after surgery. Postenucleation optic nerve enhancement did not correlate with preoperative optic nerve enhancement, chemotherapy administration, or the presence of optic nerve invasion on histopathology. No child required an orbital biopsy. None of the 88 patients were found to have subsequent orbital or metastatic disease at the last clinical follow-up visit (average, 29 months; range, 1-71).

CONCLUSION

Optic nerve contrast enhancement on follow-up MRI after enucleation for retinoblastoma seems to be a common, benign radiographic finding; none of the patients in this series developed extraocular tumor relapse. The presence of postenucleation enhancement on MRI did not correlate with preoperative chemotherapy or the presence of optic nerve invasion on histopathology. Based on our findings, intervention for isolated optic nerve enhancement on MRI is not indicated in the absence of other abnormal clinical or radiographic signs. A prospective trial with a validated radiographic grading system would be helpful to clarify the MRI features to differentiate orbital recurrence from benign postoperative enhancement.

Optic Nerve Obscuration in Retinoblastoma: A Risk Factor for Optic Nerve Invasion?

Background

The objective of this study is to evaluate the risk of optic nerve invasion associated with optic nerve obscuration at diagnosis or persisting during treatment.

Methods

Retrospective review from 2011-2016 of patients with advanced retinoblastoma (Group D/E) with complete obscuration of the nerve at diagnosis and a second group of patients with persistent, complete obscuration throughout treatment.

Results

Advanced retinoblastoma was diagnosed in 102 eyes of 86 patients. The optic nerve was obscured in 69 eyes (68%) at diagnosis. Of these, 30 (43%) underwent salvage therapy and 39 (57%) primary enucleation. Histopathologic analysis of primarily enucleated eyes showed 41% prelaminar and 15% postlaminar invasion. Four eyes in the salvage group demonstrated persistent nerve obscuration; 2 were subsequently enucleated without evidence of nerve invasion. Average follow-up was 23.5 months (range 1-62 months).

Conclusions and Relevance

Optic nerve obscuration at diagnosis may be associated with postlaminar optic nerve invasion. While persistent, complete obscuration of the optic nerve by retinoblastoma during treatment is a poor prognostic sign for both globe salvage and vision, it does not appear, in this small cohort, to increase the risk of optic nerve invasion. With appropriate control of the intraocular tumor, these eyes can be salvaged.

Pediatric Survivors of Retinoblastoma Are at Risk for Altered Bone Metabolism After Chemotherapy Treatment Early in Life

Survivors of childhood cancer frequently suffer from endocrine late effects, which are, at least partly, attributed to toxic effects of chemotherapy. Treatment of retinoblastoma typically involves chemotherapy at a very young age. The authors conducted a cross-sectional study to assess bone health in a pediatric cohort of 33 survivors of retinoblastoma (mean age: 4.4 years) who had undergone chemotherapy treatment at an especially young age (mean age: 0.76 years). Of these patients, 14 had unilateral and 19 bilateral retinoblastoma. Polychemotherapy consisted of treatment with cyclophosphamide, etoposide, vincristine, and carboplatin. Ten patients had undergone external beam radiotherapy. Clinical and biochemical parameters of growth, pubertal development, and bone health were obtained. A vitamin D deficiency was found in 51.7% of the patients, and 13.7% of patients displayed severe vitamin D deficiency. Secondary hyperparathyroidism and altered readings for bone formation or resorption markers were present in 15%. Nine percent reported bone pain or experienced fractures of the long bones after primary diagnosis. No difference between children with bilateral and unilateral disease or irradiated versus nonirradiated children was observed. The parameters of thyroid function, growth, and pubertal development were within age-appropriate norms in almost all children. In conclusion, altered parameters of bone health can be present in survivors of retinoblastoma at a young age and warrant regular follow-up in these children. The endocrine hypothalamic-pituitary axes, however, were not impaired at this early age in this group of survivors of retinoblastoma.

High-Resolution Magnetic Resonance Imaging Can Reliably Detect Orbital Tumor Recurrence after Enucleation in Children with Retinoblastoma

PURPOSE

Orbital tumor recurrence is a rare but serious complication in children with retinoblastoma, leading to a high risk of metastasis and death. Therefore, we assume that these recurrences have to be detected and treated as early as possible. Preliminary studies used magnetic resonance imaging (MRI) to evaluate postsurgical findings in the orbit. In this study, we assessed the diagnostic accuracy of high-resolution MRI to detect orbital tumor recurrence in children with retinoblastoma in a large study cohort.

DESIGN

Consecutive retrospective study (2007-2013) assessing MRI findings after enucleation.

PARTICIPANTS

A total of 103 MRI examinations of 55 orbits (50 children, 27 male/23 female, mean age 16.3±12.4 months) with a median time of 8 months (range, 0-93) after enucleation for retinoblastoma.

METHODS

High-resolution MRI using orbital surface coils was performed on 1.5 Tesla MRI systems to assess abnormal orbital findings.

MAIN OUTCOME MEASURES

Five European experts in retinoblastoma imaging evaluated the MRI examinations regarding the presence of abnormal orbital gadolinium enhancement and judged them as "definitive tumor," "suspicious of tumor," "postsurgical condition/scar formation," or "without pathologic findings." The findings were correlated to histopathology (if available), MRI, and clinical follow-up.

RESULTS

Abnormal orbital enhancement was a common finding after enucleation (100% in the first 3 months after enucleation, 64.3% >3 years after enucleation). All histopathologically confirmed tumor recurrences (3 of 55 orbits, 5.5%) were correctly judged as "definitive tumor" in MRI. Two orbits from 2 children rated as "suspicious of tumor" received intravenous chemotherapy without histopathologic confirmation; further follow-up (67 and 47 months) revealed no sign of tumor recurrence. In 90.2%, no tumor was suspected on MRI, which was clinically confirmed during follow-up (median follow-up after enucleation, 45 months; range, 8-126).

CONCLUSIONS

High-resolution MRI with orbital surface coils may reliably distinguish between common postsurgical contrast enhancement and orbital tumor recurrence, and therefore may be a useful tool to evaluate orbital tumor recurrence after enucleation in children with retinoblastoma. We recommend high-resolution MRI as a potential screening tool for the orbit in children with retinoblastoma to exclude tumor recurrence, especially in high-risk patients within the critical first 2 years after enucleation.

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.

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.

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.

Update on Ophthalmic Oncology 2013: Retinoblastoma and Uveal Melanoma

PURPOSE

The aim of this study was to discuss the clinical and translational content of the literature as well as advancement in our knowledge pertaining to retinoblastoma and uveal melanoma that were published from January to December 2013.

DESIGN

This study is a literature review.

METHODS

The search 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, fewer eyes are lost because of the expanded use of ophthalmic artery chemosurgery and intravitreal melphalan, and the past year marks a deepening in our understanding of these modalities. Knowledge on the genetic underpinnings of uveal melanoma has broadened to include genes associated with a favorable prognosis. This is accompanied by promising results in the treatment of metastatic uveal melanoma.

CONCLUSIONS

This past year, there were important advancements in our knowledge of retinoblastoma and uveal melanoma.