Abstract
Purpose:
Retinoblastoma (RB) treatments include enucleation, radiotherapy, cryotherapy, laser photocoagulation and chemotherapy. Pinealoblastomas are known to potentially occur in germline RB, most often with bilateral RB (“trilateral RB”), and may regress to pineal cysts with systemic chemotherapy. The purpose of this study is to evaluate rates of pinealoblastomas and pineal cysts detected on magnetic resonance imaging (MRI) in bilateral RB patients treated with intravenous chemotherapy (vincristine, etoposide, carboplatin - VEC) with focal consolidation or enucleation as primary therapy.
Methods:
Retrospective review of digital fundus images and medical records of RB patients who presented to the University of Illinois at Chicago, Illinois Eye and Ear Infirmary Retina Clinic from November 1, 2004 to November 1, 2014.
Results:
34 patients received treatment over the study period. 18 patients had unilateral RB, and 16 had bilateral RB. The mean age at diagnosis was 16 months. No pinealoblastomas were detected by MRI in any RB patient. Pineal cysts detected by MRI occurred in none (0%) of the 18 unilateral patients and 2 of 16 (12.5%) bilateral patients. All bilateral RB patients received 6 cycles of VEC. One bilateral RB patient (International Classification of Retinoblastoma - ICRB Group B or C in both eyes) was diagnosed at age 12 months and developed pineal enhancement at age 18 months (within the last month of 6 rounds of VEC) and a pineal cyst at age 21 months, 3 months after completing VEC. The other bilateral RB patient (ICRB Group E OD [enucleated], Group C or D OS) was diagnosed at age 7 months and had a pineal cyst detected at age 26 months, 16 months after completing VEC.
Conclusions:
The rate of pinealoblastoma detected on MRI was 0% in bilateral RB patients receiving VEC. Pineal cysts were detected by MRI in 12.5% of bilateral RB patients receiving VEC. These findings may confirm the successful prevention of pinealoblastoma growth by systemic intravenous vincristine, etoposide, and carboplatin treatment in patients with bilateral retinoblastoma.