High-dose brachytherapy (HBRT), alone or in combination with external beam radiation therapy (EBRT), produces "excellent" local control rates in pediatric soft tissue sarcoma, according to a report in the April 19th issue of the BMC journal Radiation Oncology.

The value of HBRT has consistently been demonstrated in adults with high-grade tumors, with local control of brachytherapy showing advantage over wide local excision alone, the authors explain, but limited data are available in children.

Dr. Gustavo A. Viani and colleagues from Hospital do Cancer A.C. Carmago, Sao Paulo, Brazil report their experience treating soft tissue sarcoma with HBRT in 18 pediatric patients who underwent HBRT alone or in combination with EBRT.

Fourteen patients were alive and without evidence of disease after a median follow-up of 79.5 months, the authors report, for overall survival rates of 84.4 per cent at five years and 72.4 per cent at ten years.

There were no local failures in the ten patients treated with HBRT alone, the report indicates, but one patient developed distant metastases at 45 months and died after 85 months.

There was one local failure at 22 months in the combined HBRT and EBRT group, and three patients in this group developed pulmonary metastatic disease at 18, 38, and 45 months after diagnosis.

Disease-free survival was 72.4 per cent at five and ten years, the investigators say, and overall local control was 94.5 per cent at the time of the report.

"Excellent local control with tolerable side effects have been observed in a small group of pediatric patients with soft tissue sarcoma treated by HBRT alone or in combination with EBRT," the authors conclude. "Younger patients with soft tissue sarcoma may achieve local control and prevent growth retardation with a combination of brachytherapy and moderate doses of EBRT."

Longer follow-up "is required to determine the full extent of late effects," the researchers add. "Limb preservation, functional outcome, and toxicity assessment require careful assessment in a prospective study."