Wieder, H;Ott, K;Zimmermann, F;Nekarda, H;Stollfuss, J;Watzlowik, P;Siewert, JR;Fink, U;Becker, K;Schwaiger, M;Weber, WA.PET imaging with [11C]methyl- L-methionine for therapy monitoring in patients with rectal cancer..Eur J Nucl Med Mol Imaging.2002.29.6.789-96