BACKGROUND: Although a rare complication of ionizing radiation, 
radiation-induced osteosarcoma is now more frequently recognized as radiation 
therapy has become common and cancer survival has increased. To date, 
publications on radiation-induced osteosarcoma of the cranium are limited to a 
few small series and case reports.
METHODS: Data from 175 patients with a history of sarcoma of the head at The 
University of Texas M. D. Anderson Cancer Center from 1975 to 2007 were reviewed 
to identify patients with radiation-induced osteosarcoma. The diagnostic 
criteria were: 1) osteosarcoma arose within the previously irradiated field; 2) 
new sarcoma was histologically distinct from the original neoplasm; 3) no 
evidence of new sarcoma at the time of radiation; and 4) distinct latency period 
could be recognized. Frequencies and descriptive statistics were obtained for 
the various characteristics under study.
RESULTS: The authors identified 16 patients with radiation-induced osteosarcoma 
of the cranium at their institution. The average age at diagnosis was 35 years. 
The median latency period was 12.5 years. Nine patients had skull base tumors, 
and 7 had calvarial tumors. Of the 14 patients treated surgically, 86% developed 
local recurrence. The median survival time was 29 months, and the 5-year 
survival rate was 29.6%.
CONCLUSIONS: The authors report the largest series of cranial radiation-induced 
osteosarcoma. Although radiation-induced osteosarcoma is an uncommon but dire 
complication of radiotherapy, its incidence will probably increase in the future 
as the frequency of radiation treatment and cancer survival increase. These 
tumors are locally aggressive, and despite aggressive surgical and medical 
management, they have a high rate of local recurrence and mortality.