核医学と放射線治療

A Pilot Study Comparing FLT-PET and FDG-PET in the Evaluation of Response to Cetuximab and Radiation Therapy in Advanced Head and Neck Malignancies

Abstract

Brandon M. Barney, Val Lowe, Scott H. Okuno, Bradley J. Kemp, Mark S. Jacobson BA, Katharine A. Price, Jean E. Lewis, Jan L. Kasperbauer, Debra H. Brinkmann, Robert L. Foote, Yolanda I. Garces, Wenting Wu and Jann N. Sarkaria

Background: We prospectively compared FLT-PET and FDG-PET in evaluating response to cetuximab and chemoradiotherapy for HNSCC.

Methods: Six patients with HNSCC received cetuximab followed by chemoradiotherapy. Patients had FLTand FDG-PET scans at baseline, after cetuximab, and 2 weeks into chemoradiotherapy. Changes in SUVmax on successive scans were compared to baseline. Results: After induction therapy, changes in SUVmax ranged from -2 to 32% for FLT-PET and -24 to 0% for FDGPET. After two weeks of chemoradiotherapy, changes in SUVmax ranged from -71 to 9% for FLT-PET and -80 to -7% for FDG-PET. One patient experienced consecutive increases in FLT uptake not detected by FDG-PET. No patient recurred at a median 14.6 months.

Conclusions: Functional imaging early during definitive therapy for HNSCC is feasible. Similar changes in FLT and FDG uptake are detected during chemoradiotherapy; however, distinct differences were seen after induction cetuximab therapy. Further follow-up will facilitate correlation of radiotracer uptake with clinical outcome.