2009 Volume 58 Issue 7 Pages 499-513
11C-L-methionine (MET) is the most popular PET tracer for amino acid imaging of neoplastic disease. Amino acid metabolism of cancer is associated with numerous metabolic processes favoring tumor growth. L-methionine, an essential amino acid, plays a central role in the altered metabolism of cancer cells. Specially, increased uptake of MET as measured by PET has been suggested to reflect increased transport, transmethylation rate, and protein synthesis of malignant tissue, and has less influence of radiation-induced inflammatory reaction after radiotherapy. This article discusses the role of MET-PET in imaging of brain, head and neck, chest, pelvis and other part of body. The role of MET-PET in clinical management of patients with cerebral gliomas, head and neck cancer, lung cancers, ovarian tumors, uterine carcinomas, rectal cancers, malignant melanomas, multiple myelomas or bone and soft tissue tumors is reviewed in detail. In summary, MET-PET has a high sensitivity and specificity in detecting some malignant tumors. Statistically significant differences in MET uptake have been demonstrated between high- and low-grade gliomas. Patients with a lower MET uptake has been associated with a better prognosis even if patients have the same grade glioma. The feasibility and usefulness of MET-PET for therapy assessment and follow-up after therapy have demonstrated. MET-PET appears to have a high sensitivity and specificity in differentiating recurrent brain tumor from radiation injury. MET-PET has shown its usefulness in initial diagnosis, tumor-extent delineation, biopsy planning, radiotherapy planning, assessment of response to therapy and some other clinical management of cancer patients.