9 Reporting in Brachytherapy: Dose and Volume Specification

Reporting in Brachytherapy 197

8.3 Reference points for reporting intracavitary brachytherapy 8.3.1 Reporting dose at point A Definition of point A

Point A, as defined in this report, is specified relative to the applicator as visualised on orthogonal planar films. It is located in the oblique frontal plane (ICRU Report 38) (43) containing the intrauterine source(s) and bisecting the vaginal sources. In that plane and from its intersection with the plane containing the vaginal sources, a point is taken, on the midline, cranially at a distance equal to the source-to vaginal mucosal distance (cranial contour of the vaginal sources) + 2 cm. The left and right A points are located in the oblique frontal plane, perpendicularly to the intrauterine source(s), at 2 cm laterally from the midline. Fig 6.24 : Definition of point A for different applicators according to the definition as given in the text, A: ovoids/colpostats and intrauterine tube, B: ring and intrauterine tube, C: vaginal cylinder and intrauterine tube: in addition vaginal reference points are given at the level of the vaginal sources (modified from ABS recommendations).

Fig 6.24A: Manchester/Fletcher Ovoid Applicator

Fig 6.24B : Ring Applicator

Fig 6.24C : Cylindrical Applicator