الفهرس 
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Abstract
A prospective interventional comparative study was conducted on twenty tumors, classified as group (B) retinoblastoma according to International Classification of Intraocular Retinoblastoma (ICRB). The aim of this work was to evaluate the efficacy of intravenous indocyanine green dye injection combined with diode laser transpupillary thermotherapy as a treatment modality for group (B) intraocular retinoblastoma compared to the standard protocol of treatment. The study was conducted in Ophthalmic Department, Ain Shams University Hospital in the period from August 2017 to December 2020.
Twenty (20) active group B tumors were diagnosed and classified according to the ICRB. Follow up was done on monthly basis during the course of systemic chemotherapy, then every month for the following 3 months after stopping chemotherapy. Data from further follow up visits were recorded till reporting the results of the study. The tumors were divided into two groups
group I: It included ten (10) tumors; newly diagnosed or recurrent. This group was treated with systemic chemotherapy plus ICG enhanced diode laser TTT.
group II (control group): It included ten (10) tumors; newly diagnosed or recurrent. This group was treated with systemic chemotherapy plus conventional diode laser TTT.
The study excluded children with reported allergy to iodide or any severe form of allergy, eyes with media opacity, eyes having other active retinoblastoma tumors of a more advanced stage and eyes of children with bilateral retinoblastoma with the contralateral eye having an active tumor of a more advanced stage for which the child was receiving systemic chemotherapy.
All patients in the study were evaluated by complete medical history. Tumors were evaluated under general anaethesia by detailed fundus examination, fundus photography, ocular ultrasonography and MRI of the orbit and brain. All patients received the standard systemic chemoreduction therapy for group (B) retinoblastoma within 24 hours of EUA and laser thermotherapy sessions, at the Pediatrics hospital in Ain shams University. The cycles were repeated every 28 days. All tumors were treated using focal consolidation therapy in the form of diode laser transpupillary thermotherapy using Iris Medical Oculight SLx (U.S.A).
Tumors in group I received Indocyanine green dye (0.5 mg/kg) by the intravenous route 30 seconds before laser treatment. The number of ICG injections/tumor was determined by tumor response at each follow up visit.
Data analysis included:
o Patient data.
o Tumor data.
o Data collected during the treatment period.
o Total follow up period.
o Results of treatment.
There was a statistically significant difference between the 2 groups as regards the number of laser sessions for achieving complete regression. group I needed a smaller number of laser sessions per tumor (mean=3.7, SD=±1.6) than group II (mean=4.6, SD=±1.9) despite having larger initial tumor dimensions.
The study reported that ICG-TTT allowed rapid tumor regression and hence a smaller number of laser sessions. Some tumor scars developed inherent pigmentation (from RPE stimulation by the laser), thus making them more amenable to the TTT alone.
There was a statistically significant difference between the 2 groups as regards laser power per session. group I required a smaller power per session for each tumor (mean=355.4mW, SD=±19.7) in comparison to group II (mean=376.1, SD=±36.1) despite greater initial tumor height.
The study found that ICG has significantly improved uptake of diode laser, eliminating the need for increasing the laser power to the photocoagulation levels which would disrupt the inner retinal layers.
At the end of chemotherapy sessions, all the tumors in both groups had shown total response, with the majority in group I going into Type III regression (4,40%) and the majority in group II going into Type IV regression (8,80%).
The study attributed the difference in regression pattern between the 2 groups to the difference between them in tumor size, antero-posterior location, and initial age of the child at presentation.
The study found that ICG-TTT was successful with 3 challenging recurrent masses on a hypopigmented scar and achieved complete regression.
The study supported the use of ICG-TTT as a salvage therapy in case of recurrent tumors when there is no feasibility of intraarterial chemotherapy or a desire to avoid its invasiveness and potential complications.
The study stated that although ICG has a good safety profile, with high LD 50, some ocular and systemic complications can occur with the use of ICG. One case developed dense vitreous hemorrhage which is a serious side effect. Another case developed allergy to ICG.
There was no statistically significant difference between the two groups as regards the disease free survival curves using Kaplan Meier analysis. During the period of post chemotherapy follow up, 3 tumors in group I (30%) and 2 tumors in group II (20%) developed recurrence. And one case in group I (10%) developed a new mass in a remote site.
There was 100% globe salvage rate (10/10) for group I and 88.8% (8/9) for group II till the date the study results were reported. The study stated that this should be cautiously interpreted as intraarterial chemotherapy was used as an additional salvage modality for 2 tumors in group I and one tumor in group II was censored early.
The study concluded that ICG-TTT is both efficient and safe despite some potential complications.