Dose response and local control using radiotherapy in non-metastatic Ewing sarcoma.
BACKGROUND
To determine prognostic factors for local control in the radiotherapeutic management of non-metastatic Ewing sarcoma.


METHODS
Forty patients with localized Ewing sarcoma (ES) were treated with primary site RT at one institution. Median RT dose was 55.8 Gy (range, 25.5-76 Gy). Chemotherapy was given to 34 patients (85%) with the most common regimen being vincristine, dactinomycin, cyclophosphamide, doxorubicin alternating with ifosfamide and etoposide (VACA + IE) in 10. Median follow-up for surviving patients was 12.3 years (range, 1.7-26.4 years).


RESULTS
The 5- and 10-year local control rate was 78.2%. On multivariate analysis, RT dose was the only prognostic factor to impact on local control. The 5- and 10-year local control rate was 88.7% for RT dose >or=49 Gy and was 37.5% for <49 Gy (P = 0.0002, log-rank test). For tumors <or=8 cm, the 5- and 10-year local control rate was 94.1% for RT dose >or=49 Gy and 50.0% for RT dose <49 Gy (P = 0.01, log-rank test). For tumors >8 cm, the 5- and 10-year local control rate was 85.7% for RT dose >or=54 Gy and 26.7% for RT dose <54 Gy (P = 0.006, log-rank test).


CONCLUSIONS
Radiotherapy dose was found to influence local control in ES. In particular, patients who received RT doses >or=49 Gy for tumor size <or=8 cm and >or=54 Gy for tumor size >8 cm had improved local control.
Paulino
Arnold C
AC
Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, Texas, USA. apaulino@tmh.tmc.edu
Nguyen
Thanh X
TX
Mai
Wei Y
WY
Teh
Bin S
BS
Wen
B-Chen
BC
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D003520:Cyclophosphamide / Q000008:administration & dosage; D003609:Dactinomycin / Q000008:administration & dosage; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D004317:Doxorubicin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007069:Ifosfamide / Q000008:administration & dosage; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000188:drug therapy / Q000532:radiotherapy*; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014750:Vincristine / Q000008:administration & dosage
D003609:Dactinomycin; D014750:Vincristine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D007069:Ifosfamide