Utility of 18FDG-PET/CT for head and neck cancer staging, radiation therapy planning, and follow-up

Abstract

Radiation therapy (RT) is integral in the treatment of head and neck cancer (HNSCC), with intensity-modulated radiotherapy (IMRT) and other techniques allowing for more accurate and precise dose delivery to tumor while sparing normal tissues. 18Fluorodeoxyglucose-PET, when used in concert with CT scanning (PET/CT), can assist in RT planning for HNSCC. First, PET/CT can identify additional foci of disease burden, changing radiation planning if not overall therapeutic intent. Second, PET data can influence gross tumor volume (GTV) delineation, typically producing smaller and more accurate target volumes. Consequently, dose escalation can be performed to a more limited tumor volume, either from the outset of therapy or at various times during an adaptive RT course. Follow-up PET/CT may be useful for early detection of recurrences and assessment of response after therapy; however, the optimal timing of the posttherapy study is still under investigation. A significant issue in the standardized use of PET/CT for RT planning remains the appropriate algorithm for segmenting the PET signal to delineate the GTV. Nonetheless, PET/CT-guided RT planning appears to pose multiple benefits for radiation oncologists and will likely continue to be an important advancement in the treatment of HNSCC with chemoradiotherapy. © 2012 Springer-Verlag.