Radiotherapy in the Management of Childhood Rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft-tissue sarcoma of childhood, comprising over 50% of cases. It is considered to be an embryonal tumour of skeletal muscle cell origin, frequently occurring at genitourinary and head and neck sites, although it can arise throughout the body and at sites where there is no skeletal muscle. For most cases, multimodality therapy is required to achieve the best results, incorporating induction ifosfamide, vincristine and actinomycin D-based chemotherapy and local therapy (radiotherapy and/or surgery). Recent reports from the European Paediatric Soft Tissue Sarcoma Group (EpSSG) RMS 2005 study have shown significant improvements in outcomes; high-risk rhabdomyosarcoma having a 3-year event-free survival and overall survival of about 68% and 80%, respectively. The more routine use of radiotherapy is considered to be a contributing factor to these improved results, but does also often result in significant long-term sequelae for survivors. Despite an increasing number of rhabdomyosarcoma treated with advanced radiotherapy techniques, including protons, brachytherapy and rotational intensity-modulated radiotherapy, in an effort to reduce the frequency of late complications, there remain a number of unanswered questions. Future planned collaborative group studies, such as the EpSSG Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) study, are looking to address these questions, investigating the potential benefits of preoperative radiotherapy, dose escalation and the irradiation of metastatic sites.