Trial Information

A Phase II Study of Hyperfractionated Stereotactic Radiotherapy in the Treatment of Metastatic Pediatric Sarcomas of Bony Sites

Pediatric patients with sarcoma who have limited metastases are still potentially curable
with aggressive local therapy. However, conventional moderate dose radiation is unlikely to
provide durable local control. Given the recent technologic advances in radiation delivery,
it is now possible to deliver tumoricidal doses, using stereotactic radiation over a short
time course with highly focal techniques. Stereotactic radiation has proven efficacious in
the intracranial setting and in multiple extracranial sites in adults. It has not yet been
well studied in the pediatrics population where there is a particularly strong rationale due
to the ablative doses that can be delivered to tumor while simultaneously reducing high dose
to normal tissues. The proposed trial is a single arm phase II study to determine the
efficacy of SBRT in pediatric sarcomas with surgically unresectable metastatic disease.
Oligometastatic sites eligible for treatment in this study include bony sites of disease.
SBRT will be delivered to each eligible site to a total dose of 4000 delivered in 5
fractions of 800 per fractions each day. Following completion of SBRT, patients will undergo
treatment response assessment with the use of diagnostic imaging, clinical examination, and
completion of the Brief Pain Inventory to assess quality of life. The primary objective of
this study is to determine the efficacy of SBRT delivered to a dose of 4000 in 5 fractions
of 800 each for patients greater than 3 years of age and < 40 years of age with metastatic
disease of bone secondary to pediatric sarcoma. The secondary objectives of this study
include describing the toxicity of SBRT with this regimen; assessing clinical response rate
of each target lesion; assessing long-term clinical outcomes; and assessing quality of life
following completion of treatment. For patients with potentially curable oligometastatic
disease, surgical resection in conjunction with systemic therapy remains the standard of
care. Patients on this study will continue to receive chemotherapy outside of the 2 week
window for SBRT. Issues that may limit participation include our inability to assess late
effects that may not develop till at least 10 years after therapy. For this reason, we will
limit the population in this study to patients who are surgically unresectable and would be
otherwise incurable with current standard systemic therapies.