<qa>  How many courses does G-CSF continue?At least 3 days after completion of G-CSF, patients receive high-dose carboplatin IV over 1 hour on day 1, stem cell reinfusion on day 3, G-CSF subcutaneously on days 4-18 and 43-61, and oral etoposide 3 times daily on days 21-42. Treatment continues for a maximum of 4 courses in the absence of disease progression or unacceptable toxicity. 