Retinoblastoma with cerebrospinal fluid metastasis treated with orbital and craniospinal irradiation using IMRT.

A 4-year-old male child presented with history of leucocoria, photophobia, and progressive visual deterioration in the left eye. Clinical examination and computed tomography revealed a unilateral retinoblastoma involving the left globe. He underwent enucleation of the left eye and was referred for adjuvant radiotherapy in view of optic nerve infiltration up to the line of resection. However, he did not report for treatment and presented six months later with a recurrent mass in the left orbit with intracranial extension. Cerebrospinal fluid (CSF) cytology was positive for malignant retinoblastoma cells. He received multiagent chemotherapy with vincristine, carboplatin, and etoposide along with intrathecal methotrexate. Although the recurrent orbital mass reduced significantly with chemotherapy, malignant cells persisted in the CSF. He was subsequently treated using intensity modulated radiation therapy (IMRT) to treat the left orbital mass along with craniospinal axis irradiation. Computed tomography done at three and nine months after completion of radiotherapy showed complete disappearance of orbital tumor. CSF cytology also showed no evidence of malignant cells.