That would mean a "cycle" too, and all depends on the type of chemo, and cancer they are treating, and is usually used in a specified time period to be effective, prevent resistance, and for some, started again in several weeks. In our case, it's usually 6-7 weeks, used concurrently with radiation, which is used as a radio sensitizer to make radiation work better. Some have "maintenance chemo" for a longer duration, as adjunct treatment, to prevent recurrence, prevent tumor growth progression, as palliative care. Some have neoadjunvtive treatment or Induction Chemo therapy, before current chemoradiation, radiation alone or surgery, in several cycles spaced apart. I don't know of any mild chemo, but they say targeted drugs, like Erbitux, Tarceva, are milder.