Trial Information

Rectal Cancer: Determination of the Predictive Value by Use of FDG-PET-CT Scans and Blood Proteins for the Prognosis of Patients With Rectal Cancer

This translational research part is aiming to give more insights in the way radiation injury
and tumour response develops.

It involves three parts:

1. Repetitive FDG-PET-CT scans in order to assess early tumour response monitoring.

2. Blood sampling before, during and after radiotherapy in order to find predictors for
normal tissue injury and for tumour response.

3. Extra staining of tumour biopsies.

1. FDG-PET-CT scans The FDG-PET-CT scan with i.v. contrast gives information of the tumour
metabolism and its morphology. The pre-treatment max SUV is prognostic as a high value
confers a worse prognosis. Our group showed both in vitro and in vivo that a high FDG uptake
is due to tumour hypoxia. The evolution of the max SUV during radiotherapy may thus be
predictive for the ultimate tumour response. Therefore, two extra FDG-PET-CT scans will be
done during radiotherapy for the group of patients receiving long-term radiochemotherapy:
one at day 7 and one at day 14. This will enable calculation of the max SUV kinetics during
treatment. Tumour response will be determined by FDG-PET-CT scans 3-5 days after the short-
course of radiotherapy or 6-8 weeks after the long- term radiochemotherapy.

2 Blood samples Blood collection and processing before, during and after radiotherapy will
be done according to the serum protocol. For performing ELISA's blood samples should be
collected and put in the freezer. The analysis of all blood material will be performed
months to years after collection and re-analysis with regard to the described protein groups
may be necessary depending on the outcome.

1. Before radiotherapy, 10 millilitres of blood will be taken.

2. At day 7, day 14 and 6-8 weeks after the end of radiotherapy for the long- term
radiotherapy or 3-5 days after the short - course of radiotherapy,i.e. at the same days
that the FDG-PET-CT scans will be performed, 10 millilitres serum (EDTA tube) will be
taken to investigate the evolution of the proteins during and after treatment, for its
kinetics may be important as predictive factors.

3 Extra staining of tumour biopsies The tumour biopsies may be stained with markers for
proliferation (e.g. KI 67), apoptosis (e.g. M30), hypoxia (e.g. HIF, CA 9, Glut 1 and 3) and
others (e.g. EGFR and EGFRvIII), in order to correlate these measurements with response.