Beta-Ray Brachytherapy of Retinoblastoma: Feasibility of a New Small-Sized Ruthenium-106 Plaque

Abstract

A non-comparative case observation study estimated the feasibility of brachytherapy for retinoblastoma with a newly designed ruthenium-106 plaque (label: CXS) with an 8-mm diameter of the irradiation zone. Methods: The new CXS plaque was used between 2001 and 2003 for brachytherapy of 13 retinoblastomas. Indications were recurrences after preceding local treatment or endophytic retinoblastoma with an impending vitreous tumour cell seeding. The prescribed radiation dose at the apex was 88 Gy (NIST-calibrated dosimetry). Results: The mean age at brachytherapy was 1.2 years (standard deviation, SD: 1.1 years), and the mean follow-up was 1.7 years (SD: 0.6 years). The treated tumours had a mean diameter of 2.3 mm (SD: 0.7 mm) and a mean height of 1.5 mm (SD: 0.6 mm) with a mean distance to the optic disc of 9.9 mm (SD: 2.2 mm). The mean duration of irradiation was 29.3 h (SD: 9.9 h) with a mean dose at the sclera of 213 Gy (SD: 80 Gy). Surgery was uneventful in all cases. Complete regression developed after 3.1 months (SD: 2.8 months) in all cases without a recurrence or a progression of the vitreous tumour cell seeding. The eyes developed no further side-effects besides a temporary circumscribed intra-ocular haemorrhage that emerged from the regressive tumour remnants. Conclusion: Brachytherapy with the CXS plaque seems to be a safe and reliable treatment option for small-sized retinoblastoma when laser or cryocoagulation failed to control the tumour growth or for small retinoblastoma with an incipient local tumour cell seeding on the tumour surface.

106Ruthenium brachytherapy for ciliary recurrence with supraciliary effusion in retinoblastoma

“…To our knowledge, this is not only the first report of documented ciliary body recurrence with supraciliary space effusion, but also the first successful attempt of conservative treatment of ciliary retinoblastoma. [7][8][9][10] The accumulation of fluid in the supraciliary compartment secondary to tumor growth may represent a novel intra-ocular dissemination pathway for retinoblastoma cells. We recommend …”

Recent advances and challenges in the management of retinoblastoma

“…The indications for plaque brachytherapy include solitary tumors that are located anterior to the equator up to the ora serrata and recurrent or residual tumors after primary chemotherapy or failed EBRT. [394041] Radioisotopes such as iodine (I 125 ) and ruthenium (Ru 106 ) are the most commonly used isotopes. Iodine (I 125 ) seeds are inserted into a gold carrier to protect normal surrounding tissue from radiation.…”

Neue Entwicklungen zur Genetik und Therapie des Retinoblastoms

“…Alle neuen Therapieansätze versuchen, die perkutane Bestrahlung zu vermeiden. Bei kleineren Tumoren der Gruppe A und B eignen sich lokale ablative Verfahren wie die thermische Laserkoagulation, Kryokoaguation und lokale Strahlentherapie vorzugsweise mit einem Beta-Applikator [5]. In der Behandlung fortgeschrittener Retinoblastome hat sich in …”