5
The authors performed a literature search using PubMed and the search terms "gemcitabine" and "radiation recall" to find prior cases of radiation recall attributed to gemcitabine.
 adverse event: attributed 
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: adverse event, potential therapeutic event 
Text: {0} 
Answer:
 adverse event: attributed 