Hypoxia-guided adaptive radiation dose escalation in head and neck carcinoma: A planning study

AbstractObjective. To evaluate from a planning point of view the dose distribution of adaptive radiation dose escalation in head and neck squamous cell carcinoma (HNSCC) using 18F-Fluoroazomycin arabinoside (FAZA) positron emission tomography/computed tomography (PET-CT).Material/methods. Twelve patients with locally advanced HNSCC underwent three FAZA PET-CT before treatment, after 7 fractions and after 17 fractions of a carboplatin-5FU chemo-radiotherapy regimen (70 Gy in 2 Gy per fraction over 7 weeks). The dose constraints were that every hypoxic voxel delineated before and during treatment (newborn hypoxic voxels) should receive a total dose of 86 Gy. A median dose of 2.47 Gy per fraction was prescribed on the hypoxic PTV defined on the pre-treatment FAZA PET-CT; a median dose of 2.57 Gy per fraction was prescribed on the newborn voxels identified on the first per-treatment FAZA PET-CT; a median dose of 2.89 Gy per fraction was prescribed on the newborn voxels identified on the second per-treatment F...