title: Radiation-Induced Sarcomas of the Central Nervous System: A Systematic Review.
abstract: OBJECTIVE
  Radiation-induced sarcomas (RISs) of the central nervous system are an uncommon late risk of irradiation. We conducted a systematic review of individual patient data to characterize RISs.
  
  
  METHODS
  We conducted a systemic search of the PubMed databases and compiled a comprehensive literature review. Student t tests were used to evaluate differences between variables. Kaplan-Meier analysis was used to estimate survival. Statistical significance was assessed using a log-rank test.
  
  
  RESULTS
  We analyzed 180 cases of RISs, including 59 osteosarcomas, 50 fibrosarcomas, and 16 malignant fibrous histiocytomas. The average age of onset for primary lesions was 28.8 ± 17.9 years, and the average dose of radiation delivered to the primary lesion was 51.4 ± 18.6 Gy. The latency period between radiotherapy and the onset of sarcomas was 12.4 ± 8.6 years. The median overall survival time for all sarcoma patients was 11 months, with a 5-year survival rate of 14.3%. The median survival in patients who received chemotherapy was 18 months, with a 2-year survival rate of 39.4%, whereas patients who did not receive chemotherapy had a median survival of 5 months and a 2-year survival rate of 13.7% (P < 0.0001).
  
  
  CONCLUSIONS
  The risk of secondary sarcomas in patients treated with cranial radiotherapy warrants longer follow-up periods beyond the standard time frame typically designated for determining the risk of primary tumor relapse. Moreover, chemotherapy should be considered a potential treatment option for RISs.
authors.affiliation: Laboratory of Molecular Target Therapy for Cancer, Graduate School for Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. Electronic address: ryaman@koto.kpu-m.ac.jp.
authors.forename: Ryuya
authors.initials: R
authors.lastname: Yamanaka
authors.affiliation: Laboratory of Molecular Target Therapy for Cancer, Graduate School for Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Azusa
authors.initials: A
authors.lastname: Hayano
mesh_terms: D000328:Adult; D017668:Age of Onset; D001932:Brain Neoplasms / Q000532:radiotherapy; D016543:Central Nervous System Neoplasms / Q000209:etiology* / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D011878:Radiotherapy / Q000009:adverse effects; D012509:Sarcoma / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Chemotherapy; Radiation therapy; Radiation-induced central nervous system sarcoma; Radiation-induced sarcoma