Tumor Volume Delineation in Head and Neck Cancer With Imaging Modalities: CT, PET, MRI, Compared With Pathological Tumor Volume

Accurate delineation of the gross tumor volume is crucial in radiation treatment planning. It has been reported that the gross tumor volume determined by CT (GTVCT) or MRI (GTVMRI) is larger than that by PET (GTVPET). The tumor volume determined by a standardized uptake value (SUV) has been reported not to correlate well with tumor volume as judged by the surgically resected pathological specimen (GTVPA). In order to more accurately guide radiation therapy, correlation between the pathological tumor volumes and various imaging-based tumor volume delineations is essential to validate the efficacy of these imaging methodologies