Tumor volume delineation in head and neck cancer with 18-fluor-fluorodeoxiglucose positron emission tomography: adaptive thresholding method applied to primary tumors and metastatic lymph nodes

Purpose There are several potential advantages of using 18-fluor-fluorodeoxiglucose (18F-FDG) PET for target volume contouring, but before PET-based gross tumor volumes (GTVs) can reliably and reproducibly be incorporated into high-precision radiotherapy planning, operator-independent segmentation tools have to be developed and validated. The purpose of the present work was to apply the adaptive to the signal/background ratio (RS/B) thresholding method for head and neck tumor delineation, and compare these GTVPET to reference GTVCT volumes in order to assess discrepancies.