Treatment of Retinoblastoma: The Role of External Beam Radiotherapy

Abstract

The risk of radiotherapy-related secondary cancers in children with constitutional retinoblastoma 1 (RB1) mutations has led to reduced use of external beam radiotherapy (EBRT) for RB. Presently, tumor reduction with chemotherapy with or without focal surgery (chemosurgery) is most commonly undertaken; EBRT is avoided as much as possible and is considered only as the last treatment option prior to enucleation. Nevertheless, approximately 80% of patients are diagnosed at a locally advanced stage, and only 20-25% of early stage RB patients can be cured with a chemosurgery strategy. As a whole, chemotherapy fails in more than two-thirds of eyes with advanced stage disease, requiring EBRT or enucleation. Radiotherapy is still considered necessary for patients with large tumor(s) who are not candidates for chemosurgery but who have visual potential. When radiation therapy is indicated, the lowest possible radiation dose combined with systemic or local chemotherapy and focal surgery may yield the best clinical outcomes in terms of local control and treatment-related toxicity. Proton beam therapy is one EBRT method that can be used for treatment of RB and reduces the radiation dose delivered to the adjacent orbital bone while maintaining an adequate dose to the tumor. To maximize the therapeutic success of treatment of advanced RB, the possibility of integrating radiotherapy at early stages of treatment may need to be discussed by a multidisciplinary team, rather than considering EBRT as only a last treatment option.

MiR-486-3p inhibits the proliferation, migration and invasion of retinoblastoma cells by targeting ECM1

“…Early and timely treatment of RB patients can achieve better survival rate and retention of visual function [3,4], while the tumor will grow and spread rapidly within the eyeball, invade the vitreous body and subretinal space, spread to the skull along the optic nerve, leading to the death of the patient, without timely diagnosis or treatment [5][6][7]. At present, the common treatment methods for RB are transpupillary thermal therapy, cryotherapy, chemotherapy, and ophthalmectomy, orbital exenteration and gene therapy [8,9]. Gene therapy is the treatment of a disease by manipulating a therapeutic gene or disease-related gene as a therapeutic target, which has a good prospect in the application of multiple tumor therapies [10,11].…”

Corosolic acid induces cell cycle arrest and cell apoptosis in human retinoblastoma Y-79 cells via disruption of MELK-FoxM1 signaling

“…Lack of a functional pRb1 induces defective differentiation and uncontrolled proliferation of a subset of human retinal cells, which then develop into tumors (5). Current therapy for retinoblastoma include local control of small to intermediate size tumors with laser combined with radiation and/or chemotherapy, or enucleation combined with or without systemic chemotherapy (6,7). Despite the progress in the treatment of retinoblastoma, significant issues remain unsolved.…”

Peran Radiasi dalam Tatalaksana Retinoblastoma

“…Pada AJCC edisi ke-8, diperhitungkan adanya predisposisi germinal yang termasuk dalam kriteria risiko tinggi terjadi keganasan kedua dan keganasan sekunder, yang mempengaruhi prognosis dan sintasan pasien. 5,13,14 Tatalaksana Retinoblastoma merupakan keganasan anak dengan prognosis baik jika ditatalaksana dengan pendekatan multidisiplin yang terdiri dari dokter spesialis mata, onkologi anak, onkologi radiasi, patologi, dan konselor genetika. Metode terapi yang tersedia antara lain kemoterapi, terapi fokal (misalnya krioterapi, termoterapi laser), enukleasi, radiasi eksterna dan brakiterapi plak.…”

“…18,19 Terdapat kesenjangan tingkat kesintasan retinoblastoma yang besar antara negara maju dan negara kurang berkembang, diperkirakan karena keterlambatan diagnosis sehingga pasien baru berobat saat tumor sudah stadium lanjut. 5 Retinoblastoma trilateral sebelum era kemoterapi hampir selalu fatal, dengan sintasan 5 tahun sebesar 6%. Setelah era kemo-terapi pada tahun 1995, sintasan 5 tahun meningkat hingga sebesar 44-57%.…”