Radiation late effects in children treated for orbital rhabdomyosarcoma

The experience resulting from large cooperative studies shows that correct radiation therapy at doses adequate to the tumor bulk are crucial for local control of rhabdomyosarcoma. The aim of the present study was to document the correlation between modalities and doses of radiotherapy and radiation side effects.

Between 1980 and 1997, 19 patients affected by primary orbital rhabdomyosarcoma have been followed at the University Federico II of Naples. All but three patients, who received 45, 54 and 55 Gy respectively, have been treated by immediate radiation at the dose of 60 Gy, delivered in 2 Gy fractions, five times per week, by cobalt 60 megavoltage equipment. Combined chemotherapy using vincristine and vincristine plus dactinomycin on alternate weeks was also administered as part of induction therapy.

An overall survival rate of 94.7% was registered. In our patients the majority of radiation late effects were paid by orbit and ocular adnexa. Side effects to lens and ocular structures were fewer and of low grade.

Radiation therapy is still essential for local control of orbital rhabdomyosarcoma, however radiation side effects have to be carefully considered together with the therapeutic goal to be obtained.