Ophthalmic Artery Chemosurgery for Less Advanced Intraocular Retinoblastoma: Five Year Review

BACKGROUND: Ophthalmic artery chemosurgery (OAC) for retinoblastoma was introduced by us 5 years ago for advanced intraocular retinoblastoma. Because the success was higher than with existing alternatives and systemic side effects limited we have now treated less advanced intraocular retinoblastoma (Reese-Ellsworth (RE) I-III and International Classification Retinoblastoma (ICRB) B and C). METHODOLOGY/PRINCIPAL FINDINGS: Retrospective review of 5 year experience in eyes with Reese Ellsworth (Table 1) I (7 eyes), II (6 eyes) or III (6 eyes) and/or International Classification (Table 2) B (19 eyes) and C (11 eyes) treated with OAC (melphalan with or without topotecan) introduced directly into the ophthalmic artery. Patient survival was 100%. Ocular event-free survival was 100% for Reese-Ellsworth Groups I, II and III (and 96% for ICRB B and C) at a median of 16 months follow-up. One ICRB Group C (Reese-Ellsworth Vb) eye could not be treated on the second attempt for technical reasons and was therefore enucleated. No patient required a port and only one patient required transfusion of blood products. The electroretinogram (ERG) was unchanged or improved in 14/19 eyes. CONCLUSIONS/SIGNIFICANCE: Ophthalmic artery chemosurgery for retinoblastoma that was Reese-Ellsworth I, II and III (or International Classification B or C) was associated with high success (100% of treatable eyes were retained) and limited toxicity with results that equal or exceed conventional therapy with less toxicity

Splat heat transfer and crystal growth under thermal spray conditions

International audienceA recent development in thermal spraying is to design the microstructure of coatings by controlling the sizes of the structural features within the coating so that they exhibit dimensions at the nanoscale. Improvements in performance can be in mechanical properties as well as functional properties. The size of these nano-structured features depend both on the form of the starting material (agglomerates of nanoparticles, liquid precursors) and the process conditions employed during production. Narrowing the crystal size distribution can be obtained from a carefully-controlled nucleation and growth process. This study presents a one-dimensional heat transfer model of splat cooling and solidification under plasma spray conditions. The model involves melt undercooling, nucleation and crystal growth kinetics. It intends to investigate the effect of the oxidation of various steel substrates, on the size and density of the nucleated grains

Modelling the nucleation process in alumina lamellae deposited on a steel substrate

International audienceA one-dimensional model has been developed to address the non-equilibrium heat transfer between an alumina lamella deposited by plasma spraying, and a steel or alumina substrate. The model includes under-cooling phenomenon, heterogeneous nucleation and crystal growth kinetics, allowing for the prediction of the temperature evolution in the lamella and substrate and of the nucleation temperature, grain density and size distribution. The effect on the nucleation process of the contact angle between the nucleus and substrate surface and of the quality of the contact at the splat–substrate interface is emphasized. The influence of the splat thickness, substrate material and substrate oxidation on the grain size distribution is also discussed

Numerical study of rapid solidification of alumina plasma sprayed on metallic substrates

International audienceThe recent development of the thermal spraying is to design the microstructure of coatings by controlling the sizes of the structural features within the coating. Improvements in performance can be in mechanical properties as well as functional properties. The sizes of these structural features depend essentially on the process conditions employed during production. Narrowing the crystal size distribution can be obtained from a carefully-controlled nucleation and growth process. This study describes a simple heat transfer model predicting the crystal nucleation and subsequent advance of the solidification front in an alumina sprayed splat. It involves melt undercooling, nucleation and crystal growth kinetics and the selection of the most likely nucleated alumina phase. It intends to investigate the effect of the oxide layer developed on low carbon steel substrate, on the grain sizes. Calculations were performed for various parameters: thermal contact resistance, substrate temperature. Results are presented in terms grain size densities, grain size distribution and solidification front velocit

Heat diffusion in solidifying alumina splat deposited on solid substrate under plasma sprayed conditions : application to coating formation

International audienceA plasma-sprayed coating is built up by the layering of individual splats. The latter are formed by spreading and solidification of molten particles sprayed onto a solid substrate. The coating properties depend on its microstructure and the quality of contact between the splats and the underlying layer and between the piled-up splats. This work deals with a 1D model of heat transfer between plasma-sprayed alumina splat and smooth substrate. The model is based on heat diffusion in the solidifying splat and substrate and includes undercooling phenomenon, heterogeneous nucleation and crystal growth kinetics. It assumes that splat spreading and solidification are two independent processes. The model predicts splat cooling and solidification taking into account, as far as possible, the in-flight particle properties drawn from the literature in order to study their effect on splat thermal history. The effect of the quality of contact between the splats as well as the already-deposited and solidified layer thickness on the grain size distribution and front solidification velocity is investigated

Ten-year experience with ophthalmic artery chemosurgery: Ocular and recurrence-free survival.

To report associations between disease- and treatment-related variables and rates of recurrence-free survival and ocular survival in eyes treated with ophthalmic artery chemosurgery (OAC) for retinoblastoma.Pre-post study.All eyes treated with OAC for retinoblastoma at Memorial Sloan Kettering Cancer Center between May 2006 and February 2017.This retrospective review included 452 retinoblastoma eyes treated with OAC. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS), progression-free survival (PFS) and ocular survival (OcS), and Cox regression was used to estimate hazard ratios. Eyes treated in the pre-intravitreous chemotherapy era were analyzed separately from eyes treated in the intravitreal era.Recurrence-free survival, ocular survival, associations with risk of recurrence.Disease and treatment characteristics were recorded over a median 23.6 month follow-up. One-year OcS, PFS and RFS were 96% (95% CI 93-99%), 88% (95% CI 88-94%) and 74% (95% CI 67-81%) in the pre-intravitreal era and 96% (95% CI 94-99%), 93% (95% CI 89-96%) and 78% (95% CI 72-83%) in the intravitreal era, respectively. Presence of vitreous seeds was associated with increased risk of recurrence in the pre-intravitreal era but not in the intravitreal era. Longer time interval between OAC sessions was associated with increased risk of recurrence and majority OAC access via the ophthalmic artery was associated with decreased risk of recurrence in both eras.Approximately a quarter of eyes initially treated with ophthalmic artery chemosurgery develop recurrent disease, with the majority of recurrences within the first year following completion of OAC. Despite this, these eyes have a very good chance of salvage. In eyes with vitreous seeds at presentation, intravitreal injections are useful in minimizing future vitreous recurrence. Eyes that receive the majority of drug infusions via non-ophthalmic artery routes or greater interval between OAC are more likely to recur and might warrant closer monitoring