15.7.5 Laser Photocoagulation

•Indications: Small retinal tumors (diameter less than 4.5 mm and thickness less than 2.5 cm2) in relapse after irradiation

•Complications: hemorrhage of vitreous body, detachment of retina

•The incidence of second tumor is higher following radiotherapy of patients with retinoblastoma

15.7.6 Cryotherapy

• Useful for small tumors, especially in the area of the equator

• Cryotherapy produces intracellular crystal formation, which destroys the tumor by interrupting microcirculation

15.7.7 Brachytherapy

• Implantation of radioactive seeds transiently with 40-Gy activities within 7 days

15.8Management of the Different Manifestations of Retinoblastoma

15.8.1 Unilateral Intraocular Retinoblastoma

•Enucleation, including the optic nerve, is curative; in tumor involvement of the optic nerve, therapy similar to extraocular disease may be required (see below)

•Groups 1–3: above mentioned treatment options (irradiation, laser photocoagulation, cryotherapy, chemotherapy) without enucleation

•Groups 4 and 5 with no family history: enucleation in patients with invasion of the retinal pigment epithelium, chorioid, optic nerve, and/or lamina cribrosa sclerae often necessary

15.8.2 Unilateral Extraocular Retinoblastoma

•In patients with involvement of sclera, lamina cribrosa sclerae, orbit, cerebrospinal fluid, CNS, or extracranial metastases: chemotherapy, with or without autologous transplantation eventually radiotherapy or other local control approaches, and intrathecal methotrexate therapy