Introduction: Harnessing the power of molecular imaging in particular positron emission tomography (PET) to assess response to therapy in early clinical trials has the potential to yield crucial data on efficacy and streamline drug development. Vorinostat (also known as SAHA, suberoylanilide hydroxamic acid) is a histone deacetylase (HDAC) inhibitor which alters gene transcription to inhibit proliferation and promote apoptosis.
Methods: In a phase II trial of vorinostat for cutaneous T cell lymphoma (CTCL), 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-PET/computed tomography (CT) was performed on patients with both cutaneous and nodal disease. FDG-PET/CT fuses the power of metabolic imaging from FDG-PET with the anatomic detail of CT. Scans were conducted on subjects pre-therapy and during therapy.
Results: Changes in the values of FDG uptake and measurements of nodal dimensions and thickness of cutaneous lesions were tabulated. FDG-PET/CT provided an objective measure of the response (or lack thereof) of both cutaneous and nodal disease to therapy with vorinostat. The results of this study are encouraging for the potential utility of FDG-PET/CT in future trials with HDAC inhibitors for other diseases and for CTCL with other therapies.
Conclusion: Further study will be required to determine the prognostic value of the initial PET/CT scan and response on follow-up scans.