What is the appropriate course of action if a patient experiences a rise of HCG after the first week of treatment?  Should you re-stage, re-score and institute new treatment? Or should you continue on the present treatment?

In patients with low risk disease the New England Trophoblastic Disease Center recommends giving one cycle of MTX alternating with folinic acid and then observing a log scale drop in hcg by day 18. (Ref. Devita's Principles and Practice of Oncology) A second cycle is given only if a log scale drop is not present, and considered resitant if a log scale drop is not present after second cycle of chemotherapy.

But in this presentation for low risk disease, it was suggested that MTX be given until hCG returns to normal and 1-3 cycles more after that. Any view on this?