The purpose of this study is to estimate the rate of patients in whom a significant change in the area to be irradiated will be observed between the assessment before and after laying the evaluation of Trustees.

The centering of radiotherapy is done with the pre-radiation scanner for tracking the implementation of target skin markers. On this scanner, it is often difficult for the radiation therapist to pinpoint the target volume. To improve the definition of the target volume, image fusion techniques with other imaging tests were developed.

To improve the pre-radiotherapy identification, setting up markers echo-endoscopy has been described without major complications. The impact on targeting radiotherapy was mainly described for the prostate.

The marking of digestive tumors was described by the establishment of Trustees, radiopaque markers in the lymph nodes, esophagus, stomach, pancreas, and bile ducts.

Inclusion Criteria:

• Male or female over the age of 18
• Rectal cancer diagnosis or esophagus
• Radiotherapy indication
• Signed consent to participate
• Patient affiliated to a social security system or benefiting from such a system

Exclusion Criteria:

• Pregnant women, of child-bearing potential, or lactating women
• Patient deprived of liberty or under supervision of a guardian
• Impossibility to undergo medical examinations of the study for geographical, social or psychological reasons
• Contra-indication for procedure study (infeasible EUS)
• Contra-indication for general anesthesia
• Patient (e) with disorders of hemostasis
• Patient (e) with portal hypertension