Interobserver delineation variation using CT versus combined CT + MRI in intensity-modulated radiotherapy for prostate cancer.

Purpose: To quantify interobserver variation of prostate and seminal vesicle delineations using CT only versus CT + MRI in consensus reading with a radiologist.

Material And Methods: The prostate and seminal vesicles of 13 patients treated with intensity-modulated radiotherapy for prostatic adenocarcinoma were retrospectively delineated by three radiation oncologists on CT only and on CT + MRI in consensus reading with a radiologist. The volumes and margin positions were calculated and intermodality and interobserver variations were assessed for the clinical target volume (CTV), seminal vesicles, prostate and three prostatic subdivisions (apical, middle and basal third).

Evaluation of the Sinmed Mastercouch as replacement for a standard couch.

Background And Purpose: Introducing into practice a new carbon-fibre couch necessitates its evaluation with regard to the present clinical situation.

Materials And Methods: In this study, a geometric and dosimetric evaluation has been made for the Sinmed Mastercouch as a replacement for the Elekta C-arm couch with Mylar-tennis racket combination. Geometrically, feasible gantry angles with regard to collision and beam intersection were discriminated as function of isocentric table rotation for 10 treatment isocentres.

Automatic generation of a plan optimization volume for tangential field breast cancer radiation therapy.

Background And Purpose: Dose homogeneity is one of the objectives during computer planning of postoperative radiotherapy of the conserved breast. For three-dimensional (3-D) optimization of the dose distribution using serial CT scan images, suitable volumes have to be delineated. The purpose of this study was to develop a computer-generated delineation of a plan optimization volume (POV) and an irradiated volume (IV) and to automate their use in a fast dose homogeneity optimization engine.