From UptoDate:
2006 guidelines from both the American Society of Clinical Oncology (ASCO) and the European Organization for Research and Treatment of Cancer (EORTC) recommend prophylaxis when "the anticipated incidence of febrile neutropenia is approximately 20 percent or more."
UptoDate recommends GCSF prophylaxis for
-patients who are receiving therapies where there is a likelihood of dose-limiting neutropenia
-certain high-risk patients
-patients receiving radiation therapy involving large fields
For more read "Prophylaxis of infection during chemotherapy-induced neutropenia" in UptoDate (on campus only)
