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

Abstract

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.

Introduction

Retinoblastoma is a highly malignant intraocular tumor, typically found in young children. The mainstay of retinoblastoma diagnosis and management is clinical acumen; however, several diagnostic modalities, such as ultrasonography, fluorescein angiography, and optical coherence tomography (OCT) are employed.[1] Portable hand-held OCT (HH-OCT) has become important in day-to-day retinoblastoma management. HH-OCT has been found to identify clinically “invisible” retinoblastoma, document tumor recurrence, and monitor tumor response to various therapies.[2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18] In addition, HH-OCT of the foveola has been helpful in estimating visual acuity in preverbal retinoblastoma patients.[18]

Herein, we report the HH-OCT charac teristics of two submillimeter parafoveal retinoblastomas that demonstrated <100 um growth, detected early and treated rapidly with chemotherapy and indocyanine green-enhanced transpupillary thermotherapy (ICG-TTT), in order to successfully protect the infant's foveal anatomy and ultimate visual acuity.

Case Report

A 2-month-old Caucasian female with known germline retinoblastoma mutation and fix and follow vision in both eyes (OU) was discovered to have bilateral Group B retinoblastoma using the International Classification of Retinoblastoma. There was no leukocoria or strabismus. She received 3 cycles of intravenous chemotherapy (IVC) using vincristine, etoposide, and carboplatin (VEC) and was referred for further management.

Anterior segment and intraocular pressure were normal OU. Fundus examination of the right eye (OD) revealed two noncalcified macular retinoblastomas measuring 256 μm and 376 μm in thickness by HH-OCT [Figure 1a–c]. There was a larger partially calcified retinoblastoma nasal to the optic disc OD measuring 4 mm × 4 mm × 3 mm. Fundus examination of the left eye (OS) disclosed a partially calcified white macular retinoblastoma measuring 3 mm × 3 mm × 2.5 mm. There was no subretinal fluid, subretinal seeding, or vitreous seeding OU. These findings were consistent with partially regressed Group B retinoblastoma OU.

Figure 1.

Fundus photography and hand-held optical coherence tomography images of two sub-millimeter retinoblastomas in the macula of the right eye. The dotted lines on the images represent hand-held optical coherence tomography b-scan orientation through each of the tumors. (a) Fundus photography initially showed 2 barely visible sub-millimeter retinoblastomas in the macula superiorly and nasally. (b) Hand-held optical coherence tomography of the superior macular tumor demonstrated hyperreflective retinal mass measuring 256 μm in thickness. (c) Hand-held optical coherence tomography of the nasal macular tumor demonstrated a small retinoblastoma measuring 376 μm in thickness. (d) Fundus photography of the right eye with clinically imperceptible growth of 2 sub-millimeter retinoblastomas. (e) Hand-held optical coherence tomography demonstrated retinoblastoma growth of 88 μm in thickness to 344 μm. (f) Hand-held optical coherence tomography demonstrated minor growth of 37 μm in tumor thickness to 413 μm. (g) Fundus photography of the right eye with chorioretinal scarring status post 3 sessions of foveal-sparing indocyanine green-enhanced transpupillary thermotherapy. (h) Hand-held optical coherence tomography demonstrated tumor regression to thickness of 154 μm with retinal and choroidal atrophy. (i) Hand-held optical coherence tomography with regressed retinoblastoma measuring 224 μm in thickness with retinal and choroidal atrophy

Treatment with 3 additional cycles of VEC was given and the extra-macular tumors OU were consolidated with ICG-TTT. ICG was employed for enhanced diode laser uptake in this blonde fundus. Two months following completion of IVC, retinoblastoma recurrence was noted in OU. In the OS, there was recurrent macular tumor and two new peripheral tumors, so intra-arterial chemotherapy using melphalan 5 mg was prescribed, with rapid tumor control but with choroidal ischemia.

In the OD, the two macular tumors demonstrated recurrence, near the foveola and threatening vision [Figure 1d]. By HH-OCT, there was 88 μm increase in thickness to 344 μm in the superior macular tumor [Figure 1e] and 37 μm increase in thickness to 413 μm in the nasal macular tumor [Figure 1f], so further IVC (3 cycles) plus foveal-sparing ICG-TTT was provided. After treatment [Figure 1g], HH-OCT confirmed regression of the superior macular tumor with thickness decreasing from 344 μm to 154 μm [Figure 1h]. The nasal macular tumor showed a reduction from 413 μm to 224 μm in thickness [Figure 1i]. At the last follow-up, 12 months following initial presentation, all tumors remain regressed. Fortunately, the foveal contour on HH-OCT was preserved, and the remainder of the retina was intact OD.

Discussion

In retinoblastoma care, HH-OCT has proven useful in confirming clinical findings and influencing management decisions.[2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18] In a recent report by Soliman et al.[6] that summarizes the use of OCT in 44 children with retinoblastoma, HH-OCT was found to influence the management of retinoblastoma by either confirming clinical findings (83% of OCT sessions) or changing the treatment course (17% of OCT sessions). In the case presented here, HH-OCT verified the clinical suspicion of submillimeter retinoblastoma growth OD and influenced the decision to treat with ICG-TTT. In addition, HH-OCT helped monitor response to treatment and titrated the number of ICG-TTT sessions based on the appearance of retinoblastoma by HH-OCT.

ICG-TTT is used to treat retinoblastoma that shows suboptimal response to conventional treatment or in eyes where the fundus is minimally pigmented.[19,20,21] Hasanreisoglu et al.[19] reported 42 retinoblastomas in 30 eyes of 21 patients that received ICG-TTT treatment and 79% of tumors showed complete regression after a median of 2 treatment sessions. Francis et al.[20] and Al-Haddad et al.[21] have also reported on ICG-TTT in retinoblastoma. In our patient, the minimally pigmented background fundus and previous demonstration of chemoresistance of the macular tumors OD confirmed on HH-OCT, influenced the decision to employ ICG-TTT.

HH-OCT is vital in retinoblastoma care. Herein, HH-OCT was used to confirm retinoblastoma recurrence influencing the decision to provide further treatment, and it also corroborated tumor response to therapy. HH-OCT serves an important role for retinoblastoma management, particularly in tracking submillimeter tumors.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This study was support by Eye Tumor Research Foundation, Philadelphia, PA (CLS)

Conflicts of interest

There are no conflicts of interest