Open Access Study protocol

A phase II study for metabolic in vivo response monitoring with sequential 18FDG-PET-CT during treatment with the EGFR-monoclonal-antibody cetuximab in metastatic colorectal cancer: the Heidelberg REMOTUX trial

Anne Katrin Berger1*, Carl von Gall2, Ulrich Abel18, Stefan Delorme3, Matthias Kloor4, Jennifer Ose1, Tim Frederik Weber5, Annika Stange1, Georg Martin Haag1, Uwe Haberkorn6, Florian Lordick7 and Dirk Jäger1

Author Affiliations

1 National Center for Tumor Diseases (NCT), University Medical Center Heidelberg, Heidelberg, Germany

2 Department of Nuclear Medicine, University Hospital Erlangen, Erlangen, Germany

3 Department of Radiology, German Cancer Research Center, Heidelberg, Germany

4 Department of Applied Tumor Biology, University Medical Center Heidelberg, Heidelberg, Germany

5 Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg, Germany

6 Department of Nuclear Medicine, University Medical Center Heidelberg, Heidelberg, Germany

7 Department of Oncology and Hematology, Hospital of Braunschweig, Braunschweig, Germany

8 Institute of Medical Biometry and Informatics, University Medical Center of Heidelberg, Heidelberg, Germany

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BMC Cancer 2012, 12:108  doi:10.1186/1471-2407-12-108

Published: 22 March 2012



The epidermal growth factor receptor monoclonal antibody cetuximab has proven activity in metastatic colorectal cancer. To date, the mechanisms of action are not completely understood. Especially the impact on tumor glucose metabolism, or tumor vascularization remains largely unclear. The understanding of mechanisms such as early changes in tumor metabolism is of clinical importance since there may be a substantial influence on choice and sequence of drug combinations. Early signals of response to cetuximab may prove useful to identify patients having a relevant clinical treatment benefit. The objective of this trial is to evaluate the predictive relevance of the relative change in 18 F-Fluorodeoxyglucose tumor uptake for early clinical response during short-term single agent treatment with cetuximab. Early clinical response will be routinely measured according to the response evaluation criteria in solid tumors. Accompanying research includes cytokine immune monitoring and analysis of tumor proteins and tumor genes.


The REMOTUX trial is an investigator-initiated, prospective, open-label, single-arm, single-center early exploratory predictive study. The first 18 F-FDG PET-CT is conducted at baseline followed by the run-in phase with cetuximab at days 1 and 8. At day 14, the second 18 F-FDG PET-CT is performed. Subsequently, patients are treated according to the Folfiri-cetuximab regimen as an active and approved first-line regimen for metastatic colorectal carcinoma. At day 56, clinical response is evaluated with a CT-scan compared to the baseline analysis. Tracer uptake is assessed using standardized uptake values (SUVs). The main hypothesis to be tested in the primary analysis is whether or not the relative change in the SUV from baseline to day 14 has any predictive relevance for early clinical response determined at day 56. Patients are followed until death from any cause or until 24 months after the last patient has ended trial treatment.


The aim of this trial is to evaluate metabolic changes in metastatic colorectal cancer during short-term single agent treatment with cetuximab and to analyse their potential of predicting early clinical response. This could be helpful to answer the question if early identification of patients not responding to cetuximab is possible.

Trial registration NCT200811021020; EudraCT 200901327923

Colorectal cancer; Metastases; Cetuximab; Metabolic imaging; 18F-FDG PET CT