Analysis of patient outcomes following proton radiation therapy for retinoblastoma

Abstract

PurposeProton radiation therapy (PRT) is used to treat patients with retinoblastoma (RB) and has the potential to minimize exposure of normal tissue to radiation and thus decrease the risk of toxicity and second malignancies. However, comprehensive analyses of long-term patient outcomes are not available.Methods and materialsPatients with RB who were treated with PRT at our institution between 1986 and 2012 were invited to participate in a study that was designed to assess long-term outcomes. Patients who were enrolled in the study underwent a comprehensive analysis that included oncologic, ophthalmic, endocrine, cephalometric, and quality of life (QOL) assessments.ResultsA total of 12 patients were enrolled in this study. The average length of follow-up was 12.9 years (range, 4.8-22.2 years). All study patients had bilateral disease, and the disease and visual outcomes were similar to the outcomes for all patients with RB who were treated with PRT over the same time period at our institution. An analysis of endocrine-related test results revealed no growth abnormalities or hormonal deficiencies across the cohort. Magnetic resonance imaging scans and external cephalometry showed that PRT was associated with less facial hypoplasia than enucleation. Patient and parent-proxy QOL assessments revealed that treatment for RB did not appear to severely affect long-term QOL.ConclusionsIn addition to providing an opportunity for long-term disease control and functional eye preservation, PRT does not appear to be associated with unexpected late visual, endocrine, or QOL effects in this cohort of patients with RB.

Retinoblastoma: Update on Current Management

“…Lastly, the quality of life was observed, and no difference was noted between children and their parents regarding the quality-of-life outcomes compared to the general population [38].…”

“…These include hypoplasia, hyperpigmentation, or soft tissue fibrosis. Long-term dentofacial anomalies have also been reported [36,38,40].…”

“…Moderate visual impairment is seen in 10-23% of eyes, whereas poor or no useful vision was in 20-41.7% of non-enucleated eyes. The best visual outcomes are noted in patients with early stages that spared the optic disc, macula, and fovea, suggesting that the location of tumors has an impact of visual outcome even after PRT [35][36][37][38].…”

“…Cataracts were the most common long-term complication in eyes treated with EBRT. Other ocular complications noted are radiation retinopathy, glaucoma, neovascularization, vitreous hemorrhage, retinal detachment, strabismus, and less common toxicities [35][36][37][38].…”

“…However, due to PRT physical properties that eliminate the radiation to midline structures, these adverse effects are noted to be less than in conventional radiation therapy. Therefore, endocrinopathies were almost limited in patients treated with PRT [38,39].…”