Definition of gross tumor volume in lung cancer: inter-observer variability.

Background And Purpose: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance.

Materials And Methods: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were compared on the base of geometric volume, dimensions and extensions.

Use of a simulator with CT option in radiotherapy of macular degeneration.

Purpose: To assess the accuracy of a conventional simulation procedure in radiotherapy of age-related macular degeneration.

Methods And Materials: A computed tomographic (CT) extension attached to the treatment simulator was used to acquire CT images immediately after conventional simulation in 18 patients referred for treatment of age-related macular degeneration. Analysis was performed on 16 one-sided treatment cases for whom images were obtained.