Brachytherapy as part of the multidisciplinary treatment of childhood rhabdomyosarcomas of the orbit

Abstract

Introduction: Rhabdomyosarcomas in the orbit form a major challenge in terms of cure without severe side effects in childhood cancer. Our specifically developed approach consists of applying brachytherapy to the tumor area using a mold. Analysis of its results for 20 patients was performed.

Methods and materials: Thirteen patients were referred for brachytherapy if complete remission was not reached after chemotherapy (Group I) and 7 in case of relapse (Group II). In total, 20 patients were treated between 1991 and 2007. Four were female and 16 male; their ages varied from 1.1 to 16.5 years, with an average of 8.5 years. After macroscopically radical tumor resection, molds with holes drilled to hold flexible catheters were placed into the orbit. The dose to the clinical target volume was 40-50 Gy.

Results: Three patients of Group I and 1 patient of Group II developed local recurrence and underwent exenteration. The progression-free survival in Group I is 71.9% (95% CI 0.44-1.0), in Group II 85.7% (95% CI 0.60-1.0), the overall 5-year survival rate of the entire group is 92% (95% CI 0.76-1.0). During treatment, no serious side effects were observed. The late complications encountered in this series were cataract in 2 patients, 1 of whom also developed mild retinopathy. Two patients with ptosis needed surgical correction. No facial asymmetries or bone growth anomalies were observed.

Conclusions: This entire procedure of brachytherapy with a mold offers a tailor-made treatment for orbital rhabdomyosarcomas with only few signs of late toxicity.