en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: Due to limited clinical data in pediatric-type sarcomas (rhabdomyosarcoma, Ewing&#39;s sarcoma, PNET, and desmoplastic small round-cell tumor), the aim of this study was to evaluate the demographic characteristics and identifying prognostic factors for survival. Materials and Methods: We retrospectively reviewed 110 patients with pediatric-type sarcomas. Overall and disease free survival was analyzed with the Kaplan-Meier method and log rank test. To identify prognostic factors for overall and disease free survival, multivariate survival analyses using a Cox&rsquo;s proportional-hazard regression model was performed. Results: In this study mean age of patients were 20.30 years (SD=13.61; range, 1&ndash;83 years). The survival data of 54 patients (49.1%) were obtained with median survival of 27 months. 3 and 5-year survival rate of these patients were 41.5% and 28.3% respectively. Recurrence of disease (P=0.006) and Ewing sarcoma subtype (P=0.018) were significantly associated with poor overall survival and location of the lesion in the upper extremities (P=0.007) and trunk (P=0.005) were significantly associated with a lower disease free survival. Conclusion: With multivariate analysis, the authors determined that recurrence of disease and Ewing&#39;s sarcoma subtype are poor prognostic factors for overall survival and site of origin for disease free survival among patients with pediatric-type sarcoma. In addition, gender, patient&#39;s age, and size of tumor had no significant impact on overall and disease free survival.<br> &nbsp;</div> Cancer, prognostic factor, sarcoma, small round cell, survival. 185 195 http://ijrr.com/browse.php?a_code=A-10-1-716&slc_lang=en&sid=1 E. Esmati 7900319475328460011394 7900319475328460011394 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran A. Maddah Safaei afsan1980@ymail.com 7900319475328460011395 7900319475328460011395 Yes Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran H. Nosrati 7900319475328460011396 7900319475328460011396 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran M. Babaei 7900319475328460011397 7900319475328460011397 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran M. Lashkari 7900319475328460011398 7900319475328460011398 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran F. Amouzegar Hashemi 7900319475328460011399 7900319475328460011399 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran F. Farhan 7900319475328460011400 7900319475328460011400 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran M. Mirai Ashtiani 7900319475328460011401 7900319475328460011401 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran N. Khanjani 7900319475328460011402 7900319475328460011402 No Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital, Keshavarz Blvd, Tehran, Iran A. Alibakhshi 7900319475328460011403 7900319475328460011403 No Department of Surgery, Valieasr Hospital, Keshavarz Blvd, Tehran, Iran