Nomogram predicting response after chemoradiotherapy in rectal cancer using sequential PETCT imaging: A multicentric prospective study with external validation

PurposeTo develop and externally validate a predictive model for pathologic complete response (pCR) for locally advanced rectal cancer (LARC) based on clinical features and early sequential 18F-FDG PETCT imaging.Materials and methodsProspective data (i.a. THUNDER trial) were used to train (N = 112, MAASTRO Clinic) and validate (N = 78, Università Cattolica del S. Cuore) the model for pCR (ypT0N0). All patients received long-course...