Detection of optic nerve disease in retinoblastoma by use of spectral domain optical coherence tomography

Optical coherence tomography (OCT) to image active and inactive retinoblastomas as well as retinomas

PURPOSE

To illustrate Optical Coherence Tomography (OCT) images of active and inactive retinoblastoma (Rb) tumours.

METHODS

Current observational study included patients diagnosed with retinoblastoma and retinoma who were presented at Amsterdam UMC and Jules-Gonin Eye Hospital, between November 2010 and October 2017. Patients aged between 0 and 4 years were imaged under general anaesthesia with handheld OCT in supine position. Patients older than 4 years were imaged with the conventional OCT (Heidelberg Engineering, Heidelberg Spectralis, Germany). All patients included were divided into two groups: active and inactive tumours (retinoma and regression patterns). Patients' medical records and OCT images were analysed during meetings via discussions by ophthalmologists and physicists.

RESULTS

Twelve Dutch and 8 Swiss patients were divided into two groups: 2 patients with active tumour versus 18 patients with inactive tumour. Subsequently, inactive group could be divided in two groups, which consisted of 10 patients with retinoma and 8 patients with different regression pattern types. Of all included patients, 15 were male (75%). Median age at diagnosis was 18.0 months (range 0.19-715.2 months). A total of 12 retinoblastoma (active and inactive) and 8 retinoma foci were investigated by OCT. No distinction could be made between active and inactive tumours using only OCT.

CONCLUSION

Optical coherence tomography alone cannot distinguish between active and inactive Rbs. However, handheld OCT adds useful information to the established imaging techniques in the monitoring and follow-up of retinoblastoma patients. With this study, we provide an overview of OCT images of active and inactive Rbs.

HAND-HELD OPTICAL COHERENCE TOMOGRAPHY MONITORING OF CHEMORESISTANT RETINOBLASTOMA

PURPOSE

Retinoblastoma (Rb) is a potentially fatal intraocular malignancy in children, and hand-held optical coherence tomography (HH-OCT) can assist in submillimeter detection and monitoring after treatment of Rb. Retinoblastoma located in the macula, or those with chemoresistance, can be among the most difficult to manage. We describe HH-OCT features in a case of chemoresistant macular Rb that eventually responded to plaque radiotherapy after failing intravenous chemotherapy and intraarterial chemotherapy.

METHODS

Observational case report.

RESULTS

A 15-month-old girl with leukocoria was found to have Group D Rb in the right eye of 6-mm thickness and macular Group B Rb in the left eye of 4-mm thickness. She was treated with 6-monthly cycles of systemic intravenous chemotherapy and focal consolidation therapies to both eyes, with tumor regression in both eyes. However, macular tumor in the left eye demonstrated subsequent recurrence, from regressed thickness of 792 μm on HH-OCT to a dome-shaped hyperreflective retinal mass of >2000 μm thickness. Three cycles of intraarterial chemotherapy were sufficient for tumor regression down to 977 μm thickness on HH-OCT. Six months later, macular tumor in the left eye recurred again to >2000 μm thickness and necessitated plaque radiotherapy using apex dose of 35 Gy over 95.25 hours. Hand-held OCT confirmed rapid tumor regression to 722 μm after plaque treatment and regression remained stable at 6-month follow-up.

CONCLUSION

Hand-held OCT was critical in assessment of Rb after failed intravenous chemotherapy and intraarterial chemotherapy and later documenting regression after plaque radiotherapy. Hand-held OCT is vital in providing cross-sectional imaging and measurements of small macular and paramacular Rbs.

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.

Hand-held Optical Coherence Tomography Monitoring of Submillimeter Retinoblastoma Treated with Indocyanine Green-enhanced Transpupillary Therapy

Over recent years, hand-held optical coherence tomography (HH-OCT) has become critical for retinoblastoma diagnosis and management. We report precise HH-OCT findings in a case of sub-millimeter retinoblastoma treated with foveal-sparing indocyanine green-enhanced transpupillary thermotherapy (ICG-TTT). A 2-month-old Caucasian female with bilateral Group B retinoblastoma showed two recurrent macular tumors in the right eye, demonstrating 88 μm and 37 μm of growth to 344 μm and 413 μm in thickness, respectively, on HH-OCT. Each was treated with additional intravenous chemotherapy and foveal-sparing ICG-TTT. Tumor regression to 154 μm and 224 μm was documented on HH-OCT and maintained on follow-up. HH-OCT is vital in confirming clinical findings and influencing management decisions in retinoblastoma. In this case, HH-OCT precisely documented submillimeter retinoblastoma recurrence and treatment response.

Detection and Intraretinal Localization of an 'Invisible' Retinoblastoma Using Optical Coherence Tomography

PURPOSE

To report the use of handheld spectral-domain optical coherence tomography (HHSD OCT) to identify and define the intraretinal location of a small retinoblastoma that was not detectable by indirect ophthalmoscopy.

METHODS

This is a retrospective case report of a tumor identified with HHSD OCT in a single patient.

RESULTS

A 7-week-old male was diagnosed with unilateral group E retinoblastoma in the right eye. An enucleation was completed successfully with histopathologic confirmation of the diagnosis. The normal left eye was monitored for the development of retinoblastoma, and 10 weeks after diagnosis, three new small retinoblastomas were noted in the posterior pole. Identification of the smallest of the three tumors was facilitated by HHSD OCT; it was adjacent to the optic nerve head, and involved the outer nuclear layer, outer plexiform layer, and inner nuclear layer, with the inner retina draping over the tumor.

CONCLUSION

HHSD OCT can aid the ocular oncologist in the identification of very small retinoblastomas before they are visible to the eye, which allows for earlier and potentially vision-sparing treatment of these lesions. Additionally, the ability to identify these very small tumors and to localize them anatomically within the retinal layers may aid in our understanding of retinoblastoma tumorigenesis.

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.

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.