Metastatic papillary thyroid cancer under treatment with different I-131 protocols: a mathematical model.

Abstract

A mathematical model was used to study numerically, the metastatic papillary thyroid cancer (PTC) response to protocols of treatment with radioiodine I-131 (RAI), considering different values for the RAI efficiency ratio. Besides that, scenarios with decreasing amounts of doses, and a higher dose first, followed by smaller ones, were also proposed. In some simulations the number of tumor cells did not decrease, indicating a resistance against RAI treatment conditions. The failure may mean a poorly structured treatment protocol regarding the type of therapy, doses, application intervals, or any of their combinations. RAI treatment scenarios with alternating dosages, starting with a higher dose followed by smaller ones, presented a possible successful treatment response, i.e., tumor elimination. This variation is not common in clinical practice, but the scenario sheds light on new possible forms of treatment. Through numerical simulations with the ordinary differential equations system, it was shown that mathematical models are important tools in the study of thyroid cancer and could assist in determining the most suitable treatment protocols for metastatic PTC.