Assessment of Response Before, During and After Neoadjuvant Chemoradiotherapy in Rectal Cancer Patients

Inclusion Criteria:

• Patient is at least 18 years of age.

• Patient's body weight is ≤ 120 kg.

• Histologically proven and evaluable (according to RECIST criteria) adenocarcinoma ofthe rectum (tumour <15 cm from the anal verge), staged T3-4 N0 and T1-4N1-2.

• WHO PS ≤ 2

• Adequate bone marrow, hepatic and renal function (assessed within 14 days prior tostudy entry):

• Hemoglobin >10.0 g/dL,

• Absolute neutrophil count > 1.5 x 109/L,

• Platelet count > 100 x 109/L,

• Presence of adequate contraception in fertile patients. Adequate methods ofcontraception are: intra-uterine device, hormonal contraception, condom use withspermicide.

• Written informed consent must be given according to ICH/GCP and national/localregulations.

Exclusion Criteria:

• Evidence of distant metastases.

• Prior chemotherapy or radiotherapy for rectal cancer.

• Pregnant or breastfeeding women.

• Significant impairment of intestinal resorption (e.g. chronic diarrhea, inflammatorybowel disease).

• Known allergies to intravenous contrast agents.

• Contra-indications for magnetic resonance imaging (metal implants, claustrophobia,etc. ).

• Previous or concurrent malignancies at other sites with the exception of surgicallycured or adequately treated carcinoma in-situ of the cervix and non-melanoma skincancer.

• History of uncontrolled seizures, central nervous system disorders or psychiatricdisability judged by the investigator to be clinically significant precludinginformed consent or interfering with compliance for oral drug intake.

• Presence of any psychological, familial, sociological or geographical conditionpotentially hampering compliance with the study protocol and follow-up schedule;those conditions should be discussed with the patient before registration in thetrial.