Outcomes of Proton Beam Radiation Therapy for Retinoblastoma With Vitreous Seeds

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.

Feasibility of Proton Beam Therapy as a Rescue Therapy in Heavily Pre-Treated Retinoblastoma Eyes

Simple Summary

A variety of therapies are available for the treatment of retinoblastomas. Nevertheless, despite exhaustion of all therapeutic methods, refractory or recurrent courses of the disease occur. In eyes with a function worthy of preservation radiation therapy may become unavoidable. Proton beam therapy, compared to conventional photon-based radiotherapy, is a highly conformal form of radiation therapy with a high biological effectiveness with a simultaneously reduced probability of radiation-related side-effects and induction of secondary primary malignancies. The aim of our retrospective study was to evaluate the efficacy of proton beam therapy as rescue therapy in 15 heavily pretreated retinoblastoma eyes. In our retrospective series of a highly negatively selected patient population, we were able to preserve 60% of the eyes with a manageable side effect profile. A cataract, as the most common long-term complication, was evident in 44.4% of the preserved eyes. There was no in-field second tumor manifestation during follow-up, therefore the preliminary data of this study and series published by others suggest that the risk is significantly lower after proton beam therapy compared to conventional external beam radiation therapy using photons.

Abstract

Despite the increased risk of subsequent primary tumors (SPTs) external beam radiation (EBRT) may be the only therapeutic option to preserve a retinoblastoma eye. Due to their physical properties, proton beam therapy (PBT) offers the possibility to use the effectiveness of EBRT in tumor treatment and to decisively reduce the treatment-related morbidity. We report our experiences of PBT as rescue therapy in a retrospectively studied cohort of 15 advanced retinoblastoma eyes as final option for eye-preserving therapy. The average age at the initiation of PBT was 35 (14–97) months, mean follow-up was 22 (2–46) months. Prior to PBT, all eyes were treated with systemic chemotherapy and a mean number of 7.1 additional treatments. Indication for PBT was non-feasibility of intra-arterial chemotherapy (IAC) in 10 eyes, tumor recurrence after IAC in another 3 eyes and diffuse infiltrating retinoblastoma in 2 eyes. Six eyes (40%) were enucleated after a mean time interval of 4.8 (1–8) months. Cataract formation was the most common complication affecting 44.4% of the preserved eyes, yet 77.8% achieved a visual acuity of >20/200. Two of the 15 children treated developed metastatic disease during follow-up, resulting in a 13.3% metastasis rate. PBT is a useful treatment modality as a rescue therapy in retinoblastoma eyes with an eye-preserving rate of 60%. As patients are at lifetime risk of SPTs consistent monitoring is mandatory.

Clinical and magnetic resonance imaging features of 14 patients with trilateral retinoblastoma

Background

Our study aimed to comprehensively investigate the age of onset, magnetic resonance imaging (MRI) features, and prognosis of children with trilateral retinoblastoma (TRB).

Methods

We included 14 patients with TRB diagnosed or followed up in our hospital. The age of onset and MRI features of the intraocular tumor and intracranial lesions were evaluated. A follow-up study was also conducted.

Results

A total of 11 participants were diagnosed with concurrent TRB at the age of 11.1±7.4 months, and 3 participants had late-onset TRB at age 37±19.1 months. The incidence of TRB with unilateral eye involvement was 7.1% (1/14). The intraocular tumors showed intense enhancement in contrast-enhanced T1-weighted images (WI) and significant diffusion restriction in diffusion WI (DWI) with an apparent diffusion coefficient (ADC) of (0.619±0.22)×10^-3 mm²/s. The intracranial lesions showed similar DWI aspects with an ADC value of (0.680±0.206)×10^-3 mm²/s. Therapeutically, 8 participants had a period of intraocular tumor stabilization and significant intracranial lesion volume reduction after chemotherapy, and 6 participants had given up treatment. Only 2 participants who simultaneously received high-dose chemotherapy and autologous hematopoietic stem cell rescue were still alive with no recurrence at 24 and 54 months of follow-up. The 1-, 2-, and 3-year overall survival (OS) rates were 80%, 18.75%, and 12.5%, respectively.

Conclusions

Patients with unilateral or bilateral RB can develop TRB. The intraocular and intracranial tumors showed slightly different ADC values. High-dose chemotherapy, combined with stem cell rescue can significantly improve survival. A long term and scheduled follow-up before 60 months of age is necessary for screening later-onset TRB patients.

Association of electroretinography with visual outcomes after ophthalmic artery chemosurgery for retinoblastoma in ICRb D and E eyes

Importance

Predictions of visual outcomes are useful in clinical and family decisions regarding treatment for retinoblastoma. Very little has been published on the association of post-treatment visual acuity with pre-treatment electroretinography (ERG), which can be performed on infants too young to reliably quantify visual acuity.

Objective

To report associations of pre-treatment ERG with post-treatment visual acuity in eyes with advanced retinoblastoma treated with ophthalmic artery chemosurgery (OAC).

Design

Retrospective case-control study of eyes treated from 2006 through 2017, with mean follow-up of 51 months (range 2.3–150 months).

Setting

Single large academic center.

Participants

Group D and E eyes treated with OAC at Memorial Sloan Kettering Cancer Center with recorded visual acuity and ERG (30Hz flicker).

Main outcome and measure

Snellen visual acuity (uncorrected) compared to initial 30Hz flicker ERG.

Results

This study included 157 Group D and E eyes. Results of the Jonckheere-Terpstra test for trend were statistically significant and indicated that eyes with lower pre-treatment ERG readings tended to have more visual impairment post-treatment. Among eyes with initial ERG 75+ μV, 11 of 32 eyes (34%) had visual acuity 20/40 or better. Among eyes with ERG 0 μV, 44 of 46 (96%) had visual acuity of 20/200 or worse.

Conclusions and relevance

Eyes with advanced intraocular retinoblastoma treated with OAC can achieve excellent visual acuity, but poor ERG at initial visit is associated with poor visual acuity after treatment in the majority of eyes. Expectations regarding visual potential may influence decisions about treatment.