Radiotherapy for pediatric non-rhabdomyosarcoma soft tissue sarcomas: a comprehensive review.

Background: For children with non-rhabdomyosarcoma soft tissue sarcomas, a risk-adapted treatment approach is generally used in order to minimize treatment-related morbidity and mortality in low-risk patients and maximize the benefit in high-risk patients. Our aim in this review is to discuss the prognostic factors, riskadapted treatment options and the details of radiotherapy.

Methods: The publications reached by searching the keywords `pediatric soft tissue sarcoma`, `nonrhabdomyosarcoma soft tissue sarcoma (NRSTS)`, and `radiotherapy` in Pubmed database were evaluated in detail.

Results: Today, based on prospective COG-ARST0332 and EpSSG studies, a risk-adapted multimodal treatment approach has become the standard in pediatric NRSTS. According to them, adjuvant chemotherapy/ radiotherapy can be safely omitted in low-risk patients, while adjuvant chemotherapy/radiotherapy or both are recommended in intermediate and high-risk groups. Recent prospective studies for pediatric patients have reported excellent treatment outcomes with smaller radiotherapy fields and lower doses than adult series. The primary goal of surgery is maximal tumor resection with negative margins. In cases that are initially unresectable, neoadjuvant chemotherapy and radiotherapy should be considered.

Conclusions: A risk-adapted multimodal treatment approach is the standard in pediatric NRSTS . Surgery alone is sufficient in low-risk patients, and adjuvant therapies may safely be omitted. On the contrary, in intermediateand high-risk patients, adjuvant treatments should be applied to reduce recurrence rates. In unresectable patients, the chance of surgery increases with the neoadjuvant treatment approach and thus treatment results may improve. In the future, outcome might be improved with further clarification of molecular features and targeted therapies in such patients.