Figure 3. A gross tumour volume on CT scan in a patient with oropharyngeal carcinoma, and biological target volume on the corresponding ⁶⁴Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) (⁶⁰Cu-ATSM) image. Reproduced with kind permission from: Chao KS, Bosch WR, Mutic S, et al. A novel approach to overcome hypoxic tumor resistance: Cu-ATSM-guided intensity-modulated radiation therapy. Int J Radiat Oncol Biol Phys 2001;49:1171–82.