Palma, PabloConde-Muíño, RaquelRodríguez-Fernández, AntonioSegura-Jiménez, InmaculadaSánchez-Sánchez, RocíoMartín-Cano, JavierGómez-Río, ManuelFerrón, José ALlamas-Elvira, José M2012-06-142012-06-142010-12-15Palma P, Conde-Muíño R, Rodríguez-Fernández A, Segura-Jiménez I, Sánchez-Sánchez R, Martín-Cano J, et al. The value of metabolic imaging to predict tumour response after chemoradiation in locally advanced rectal cancer. Radiat Oncol. 2010 Dec 15;5:119http://hdl.handle.net/10668/409Preliminary data of this work were presented by RCM and awarded at the 2009 Annual Meeting of the Spanish Society of Coloproctology (AECP) held in Barcelona.Background: We aim to investigate the possibility of using 18F-positron emission tomography/computer tomography (PET-CT) to predict the histopathologic response in locally advanced rectal cancer (LARC) treated with preoperative chemoradiation (CRT). Methods: The study included 50 patients with LARC treated with preoperative CRT. All patients were evaluated by PET-CT before and after CRT, and results were compared to histopathologic response quantified by tumour regression grade (patients with TRG 1-2 being defined as responders and patients with grade 3-5 as non-responders). Furthermore, the predictive value of metabolic imaging for pathologic complete response (ypCR) was investigated. Results: Responders and non-responders showed statistically significant differences according to Mandard's criteria for maximum standardized uptake value (SUVmax) before and after CRT with a specificity of 76,6% and a positive predictive value of 66,7%. Furthermore, SUVmax values after CRT were able to differentiate patients with ypCR with a sensitivity of 63% and a specificity of 74,4% (positive predictive value 41,2% and negative predictive value 87,9%); This rather low sensitivity and specificity determined that PET-CT was only able to distinguish 7 cases of ypCR from a total of 11 patients. Conclusions: We conclude that 18-F PET-CT performed five to seven weeks after the end of CRT can visualise functional tumour response in LARC. In contrast, metabolic imaging with 18-F PET-CT is not able to predict patients with ypCR accuratelyenAdultoAncianoAnciano de 80 o más AñosCarcinomaQuimioterapiaTerapia CombinadaFemeninoFluorodesoxiglucosa F18HumanosMasculinoMediana EdadTomografía de Emisión de PositronesValor Predictivo de las PruebasPronósticoNeoplasias del RectoSensibilidad y EspecificidadMedical Subject Headings::Named Groups::Persons::Age Groups::AdultMedical Subject Headings::Named Groups::Persons::Age Groups::Adult::Aged::Aged, 80 and overMedical Subject Headings::Diseases::Neoplasms::Neoplasms by Histologic Type::Neoplasms, Glandular and Epithelial::CarcinomaMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Therapeutics::Drug Therapy::Chemotherapy, AdjuvantMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Therapeutics::Combined Modality TherapyMedical Subject Headings::Chemicals and Drugs::Carbohydrates::Deoxy Sugars::Deoxyglucose::Fluorodeoxyglucose F18Medical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Check Tags::MaleMedical Subject Headings::Named Groups::Persons::Age Groups::Adult::Middle AgedMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Diagnostic Imaging::Tomography::Tomography, Emission-Computed::Positron-Emission TomographyMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Research Design::Sensitivity and Specificity::Predictive Value of TestsMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::PrognosisMedical Subject Headings::Diseases::Neoplasms::Neoplasms by Site::Digestive System Neoplasms::Gastrointestinal Neoplasms::Intestinal Neoplasms::Colorectal Neoplasms::Rectal NeoplasmsMedical Subject Headings::Check Tags::Femaleresearch article21159200open access10.1186/1748-717X-5-1191748-717XPMC3012041