Abstract
2712
Introduction: Metastatic differentiated thyroid cancer CDRC) cells not infrequently lose their ability to take up 131I,. Heretofore and in these patients, 131I therapy is no longer a therapeutic option. However, with further developments with genomic test and molecular imaging of DTC, selected patients and selected agents may reestablish 131I uptake in metastatic DTC, thereby allowing additional 131I therapies. This education exhibit is a review of the publications to date regarding the patients and agents were administered to either re-differentiate (i.e., re-establish 131I uptake) or enhance (i.e., increase 131I uptake in patients who had visible but low 131I uptake).
Methods: A literature search was perform using multiple search tools (e.g., Pub Med, Google Scholar, etc.) Medical subject heading (MESH) were used including but not limited to differentiated thyroid cancer, 131I, therapy, radioiodine refractory, BRAF, RAS, etc., selumetinib , trametinib, dabrafenib, etc. Articles prior to 2013 such as those evaluating rosiglitazone were not evaluated.
Results: Of the articles identified, the author selected nine articles that were subsequently evaluated for the use of agents to re-differentiate and/or enhance 131I uptake for potential subsequent 131I therapy. The review tabulated—when available--the following information: 1) age, 2) gender, 3) molecular profile, 4) radioiodine scan (including isotope, activity and time of administration of that isotope) prior to treatment with a potential redifferentiation/enhancement (R/E) agent, and the results of that scan, 5) R /E agent(s) administered including dose, frequency, and duration of administration of those agents before subsequent radioiodine scan and 131I treatment, 6) isotope, activity and time of administration of isotope and results of radioiodine scan after the treatment with a potential (R/E)agent, and the results of that scan , 7) number of patients who received an subsequent 131I therapy, the therapeutic activity administered, and reported outcomes, and 8) the results of any patients receiving a second R/E evaluation with or without a second 131I therapy
Conclusions: Strong preliminary data report that select agents offer significant potential for re-establishing 131I uptake in patients with metastatic differentiating thyroid cancer who have no visible 131I uptake on either a diagnostic or a prior post-therapy radioiodine scan. Equally exiting. is the potential that these agents may have utility in patients who have already demonstrate 131I uptake in metastatic DTC but in cases where the 131I uptake is low, thereby potential allowing more Gy (rad) to be delivered per GBq (mCi) of activity administered in turning increase the likelihood of a better therapeutic effect and/or a reduction in the administered activity accomplishing the same desired therapeutic effect while reducing the Gy (rad) delivered to non-target organs such as bone marrow and salivary glands. This is a very exciting area of research.
