A single-arm study of systemic and sub-Tenon chemotherapy for Groups C and D intraocular retinoblastoma: A Children's Oncology Group study (ARET 0231)

Longitudinal Comparison of Orbital Volumes from Enucleated Eyes with Hydroxyapatite Orbital Implant in Unilateral Retinoblastoma Patients

PURPOSE

To compare the orbital volume between enucleated and contralateral, uninvolved orbits over a 5-year period in patients with unilateral retinoblastoma who underwent enucleation with hydroxyapatite (HA) implant placement by a single surgeon.

METHODS

A retrospective review was performed on the clinical records and radiographic images of unilateral retinoblastoma patients who underwent enucleation with primary HA implantation from 2003 to 2020 at a single institution. Bilateral orbital volume measurements were taken from the initial postoperative MRI scan and again at 1- and 5-years postenucleation. The main outcome measure was the longitudinal change in volume difference (∆𝑉). The implant size, age at enucleation, and sex were also evaluated. A linear mixed-effect model was used for analysis.

RESULTS

A total of 124 patients (73 males) with HA implants following enucleation were included. Overall, the unaffected orbit trended toward having a greater volume compared with the enucleated orbit, but this was not statistically significant (β = 0.003; p = 0.122). The mean age at enucleation was 2.4 years. The median time between enucleation and the initial, 1-year, and 5-year postoperative MRIs was 6 months, 17 months, and 55 months, respectively. There was no statistical correlation between age at enucleation, gender, implant size, or orbital volume at any time points ( p > 0.05).

CONCLUSIONS

Patients treated with enucleation and primary HA implant placement for unilateral retinoblastoma did not display significant asymmetry in orbital volume on 5-year postenucleation MRIs, suggesting that HA implants promote orbital growth comparable to a nonenucleated orbit in the pediatric population.

A multi-institutional feasibility study of intra-arterial chemotherapy in children with retinoblastoma. A Children's Oncology Group study (COG ARET12P1)

BACKGROUND

Intra-arterial chemotherapy (IA) as a treatment to salvage the eye with advanced retinoblastoma is increasingly utilized based on successes reported by institutions around the world mainly through retrospective studies.

OBJECTIVE

To study the feasibility of delivering melphalan directly into the ophthalmic artery in a multi-institutional prospective study in children with newly diagnosed unilateral group D retinoblastoma.

METHODS

The Children's Oncology Group (COG) initiated study ARET12P1 in 2014 and was open to nine institutions. Eligible patients older than six months of age were enrolled. The feasibility of delivering three injections of melphalan into the ophthalmic artery every 28 days was assessed.

RESULTS

Nine institutions participated in this trial. Fourteen patients were enrolled, two of whom were unevaluable for feasibility. Four patients experienced a feasibility failure. In two patients, the ophthalmic artery could not be accessed for the second IA injection, in one the artery could not be accessed for the first injection, and one patient experienced grade 4 hypotension during the procedure.

CONCLUSION

Delivery of prescribed therapy within the context of this study did not meet the feasibility goals of the study with only a 67% feasibility success rate. These results should caution centers that plan to initiate this treatment and suggest investment in training to achieve technical expertise or referral to centers with expertise.

A single-blinded, randomized controlled trial of standard versus higher dose carboplatin-based intravenous chemotherapy for group D and E retinoblastoma

BACKGROUND

Access to intra-arterial chemotherapy for retinoblastoma in low- and middle-income countries (LMICs) is limited. There is a need to optimize the efficacy of systemic chemotherapy for advanced intraocular retinoblastoma, particularly in LMICs. The aim was to compare the efficacy of standard versus higher dose carboplatin-based intravenous chemotherapy for group D and E retinoblastoma.

METHODS

The single-center, single-blinded, randomized study was conducted during 2019-2021. Patients with newly diagnosed group D or E retinoblastoma were randomized to receive vincristine, etoposide, and standard versus higher dose (<36 months: 18.6 vs. 28 mg/kg; ≥36 months: 560 vs. 840 mg/m² ) carboplatin. Examination under anesthesia and ultrasonography was performed at diagnosis and following three cycles of chemotherapy. Group E eyes with poor likelihood of globe/vision salvage at diagnosis were excluded.

RESULTS

Thirty-two eyes of 30 patients were analyzed: 17 group D and 15 group E eyes. The tumor response to chemotherapy with regards to regression pattern (p = .72), tumor shrinkage (diameter: p = .11, height: p = .96), subretinal seeds (p = .91), and vitreous seeds (p = .9) were comparable between the two treatment arms. The globe salvage (group D [82% vs. 67%; p = .58]; group E [12.5% vs. 29%; p = .57]) and salvage of meaningful vision (group D [100% vs. 75%; p = .13]; group E [100% vs. 50%; p = .48]) were comparable between standard and higher dose arms. No excess treatment-related toxicity was observed in the higher dose arm.

CONCLUSIONS

Higher dose carboplatin-based intravenous chemotherapy did not result in superior globe or vision salvage in group D or E retinoblastoma.