Whilst treatment is taking place the serum hCG level should be monitored twice a week. The results from this are monitored at Charing Cross Hospital to check if the disease is responding well to treatment and that the hCG level falling appropriately as shown in Figure 6. Of the patients who start with Methotrexate treatment approximately 1/3rd will have to change to more intensive treatment. We are able to tell who needs to step-up to more intensive treatment by the pattern of the hCG levels.
Figure 6. Graph of hCG falling appropriately in a low risk patient.
If the hCG level rises for 2 consecutive samples or remains much the same for 3 samples we generally recommend that the next step in intensity of the treatment is used. All patients who need to change to more intensive treatment will be called back to Charing Cross to discuss this and to start the next treatment. As a rough guide when a change from Methotrexate is needed this will be to EMA-CO chemotherapy if the hCG level is over 1000 or to Actinomycin D chemotherapy if the hCG level is less than 1000. Figure 7 shows the hCG results and treatment graph of a patient who started on Methotrexate and then changed over to EMA-CO chemotherapy to successfully complete treatment.
Figure 7. hCG results and treatment graph of a patient who started on Methotrexate and changed over to EMA-CO.