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.
Keywords: Chemotherapy; Radiation therapy; Radiation-induced central nervous system sarcoma; Radiation-induced sarcoma.
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