[Gross tumor volume and clinical target volume: esophageal tumors]

Delineation of organs at risk

The delineation of organs at risk is the basis of radiotherapy oncologists' work. Indeed, the knowledge of this delineation enables to better identify the target volumes and to optimize dose distribution, involving the prognosis of the patients but also their future. The learning of this delineation must continue throughout the clinician's career. Some contour changes have appeared with better imaging, some volumes are now required due to development of knowledge of side effects. In addition, the increasing survival time of patients requires to be more systematic and precise in the delineations, both to avoid complications until now exceptional but also because re-irradiations are becoming more and more frequent. We present the update of the recommendations of the French Society for Radiation Oncology (SFRO) on new findings or adaptations to volumes at risk.

[Target-volume contours in radiotherapy. General principles]

Target volume delineation remains an important medical step for conformal radiotherapy. In this general presentation are discussed: the main difficulties for evaluation of gross tumor (GTV) and clinical target volume (CTV), the main recommendations for representation according to ICRU 62 report, differences observed during inter-observer volume comparisons.