Figure 2. FDG-PET and CT studies in patients with gastric cancer treated by pre-operative chemotherapy. The tumour demonstrates intense FGD uptake prior to therapy. Two weeks after initiation of therapy, tumour FGD uptake has been reduced to background levels. Histological evaluation of the resected tumour specimen revealed less than 10% viable tumour cells after 3 months of chemotherapy. Reproduced with kind permission of the American Society of Clinical Oncology from: Ott K, et al. Prediction of response to preoperative chemotherapy in gastric carcinoma by metabolic imaging: results of a prospective trial. J Clin Oncol 2003;21:4604–10.