he application of the methods may facilitate the noninvasive imaging of therapeutic tumor responses to specific drug treatments to provide a reliable index of their potential efficacy and as a monitor of mechanisms of action in the selective destruction of tumor cells.
The research article discusses the potential for the expanded use of quantitative PET molecular imaging to assess the efficacy of novel targeted therapeutics in the treatment of cancer. The use of radiolabelled biomarkers serves as a molecular tag which can be traced using PET imaging tools to delineate the molecular interactions between a targeted drug and the tumor cells destined for destruction. The implementation of the molecular tools allows researches to determine whether the drug effectively interacts with its selected target and the concentration of drug that actually reaches the tumor site following drug administration. Non-specific interactions of the drug with non-tumor tissue may also be assed using this methodology. The authors reviewed the results of several clinical trials of this methodology used to assess the efficacy of several important new classes of targeted chemotherapeutics, including protein tyrosine kinase inhibitors (PTKIs) and epidermal growth factor receptor (EGFR) ligands. In the latter case, several drugs approved for cancer treatment by the US FDA, including lapatinib, gefitinib ,and erlotinib, were assessed using this nuclear medicine application. Each of these drugs has produced equivocal results in patients with lung cancer and other tumors that overexpress the EGFR. Several research trials involving labeled chemotherapeutics were cited and data presented indicated that in some cases, reliable data were produced by this nuclear medicine molecular assessment approach.
The authors have presented a compelling theoretical argument to support the use of PET imaging technology in the molecular assessment of therapeutic responses to targeted cancer drugs. This