PET imaging with [11C]methyl-L-methionine for therapy monitoring in patients with rectal cancer

• Published in: European journal of nuclear medicine and molecular imaging 2002-06, Vol.29 (6), p.789-796
• Main Authors: WIEDER, Hinrich, OTT, Katja, WEBER, Wolfgang Andreas, ZIMMERMANN, Frank, NEKARDA, Hjalmar, STOLLFUSS, Jens, WATZLOWIK, Petra, SIEWERT, Jörg-Rüdiger, FINK, Ulrich, BECKER, Karen, SCHWAIGER, Markus
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biological and medical sciences; Digestion. Liver. Biliary tract. Spleen. Pancreas; Female; Follow-Up Studies; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Methionine - pharmacokinetics; Middle Aged; Neoadjuvant Therapy; Neoplasm Staging; Predictive Value of Tests; Radionuclide investigations; Radiopharmaceuticals - pharmacokinetics; Rectal Neoplasms - diagnostic imaging; Rectal Neoplasms - metabolism; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Reference Values; Sensitivity and Specificity; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tomography, Emission-Computed; Tumors
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-002-0779-4

In this study we evaluated whether positron emission tomography (PET) using the amino acid [11C]methyl- L-methionine (MET) may be used for therapy monitoring in patients with rectal cancer who are undergoing preoperative chemoradiotherapy. A total of 41 MET-PET scans were performed in 26 patients with locally advanced rectal cancers. All patients were examined prior to chemoradiotherapy. In 15 patients, MET-PET was repeated after preoperative chemoradiotherapy (45 Gy radiation dose, 250 mg 5-fluorouracil as continuous infusion). MET uptake prior to and after the completion of chemoradiotherapy was correlated with changes in T stage and histopathological regression. All tumours were visualised with high contrast and had a significantly higher SUV (5.7+/-2.2) than normal rectum (2.7+/-0.9) and all other organs in the field of view except the small intestine (3.9+/-1.7). In all tumours studied prior to and after chemoradiotherapy, MET uptake decreased during therapy (SUV before therapy, 6.2+/-2.3; SUV after therapy, 2.6+/-1.2; P=0.0007). However, the degree of change in MET uptake was not correlated with histopathological tumour response. In conclusion, primary rectal cancer can be imaged with MET-PET. However, for the studied chemoradiotherapy regimen, MET-PET did not allow an assessment of the response to therapy.