Chemothermotherapy in the management of retinoblastoma

To evaluate the results of chemothermotherapy for the treatment of retinoblastoma.

Non-comparative interventional case series.

Fifty-one children (65 eyes and 103 tumors) were treated with chemothermotherapy in a single institution from January 1995 to May 1998.

Chemothermotherapy consists of a combination of transpupillary thermotherapy delivered shortly after intravenous (IV) injection of carboplatin (560 mg/m(2)). Each tumor is treated separately with a diode laser using a microscope. Laser intensity, spot size, and duration are adapted to the size of each tumor and to the clinical response. After 8 days, thermotherapy alone is repeated. This cycle is performed from one to six times, every 28 days. The treatment data and outcome are analyzed separately.

Assessment of local tumor control.

One hundred three tumors were treated in 65 eyes of 51 children. Age at diagnosis was 0 to 60 months (median, 7 months). Median tumor diameter at the time of treatment was 3.5 mm (range, 1.5-12 mm). Laser modalities were as follows: median intensity, 450 mW (range, 150-1000 mW); median spot size, 1.2 mm (range, 0.3-2.0 mm); and median number of cycles required to obtain tumor control, three. Tumor regression was obtained for 99 tumors (96.1%) after a median follow-up of 30 months (17-61 months). Seven tumors relapsed after initial control (6.8%). Salvage treatment (external beam radiation, iodine plaques, or enucleation) was necessary for a total of 11 tumors (10.7%). The only risk factor for relapse was the initial diameter of the lesion greater than 3.5 mm, whereas the other tumor characteristics or treatment variables were not significantly correlated with relapse. Ninety-seven percent of treated eyes were able to be preserved, and 92% of cases were treated without external beam radiation.

Chemothermotherapy is an effective technique to treat small- to medium-sized retinoblastomas in children, avoiding external beam irradiation.