9 Reporting in Brachytherapy: Dose and Volume Specification

190 Reporting in Brachytherapy

Fig 6.20 Reporting Intraluminal Brachytherapy

Fig 6.20A : Reporting in Endovascular Brachytherapy (coronary artery). Reference Lumen Diameter (RLDi) is 3 mm, radius (r) is 1.5 mm. Prescribed Dose (PD) is at 2.5 mm. Reference Depth is at 1 mm (RD). Reference Lumen Dose Point (RLDP) and Reference Depth Dose Point (RDDP) are also indicated. In this case PD and RDDP are identical. For peripheral arteries RD is at 2 mm. For non-centred applicators minimum and maximum doses should also be given (for details see Fig 6.17 and Fig 32.3B). The Length of the Reference Isodose (RIL) is defined as the length of the 90%-isodose at the reference depth of 5 mm.

Fig 6.20B: Reporting in Endobronchial Brachytherapy (small diameter applicator) Applicator Diameter (AD) is 2 mm, radius (r) is 1 mm. Prescribed Dose (PD) is at 10 mm from the source axis. Reference Depth (RD) is at 5 mm from the Applicator Surface (AS). Reference Depth Dose is given at the the RD (6 mm (5+1) from the source axis). Dose at the Applicator Surface (AS) is also given. For non-centred applicators minimum and maximum doses should also be given (for details see Fig 6.17 and Fig 32.3B) In order to clearly indicate the doses at the reference depth (RD) and at the Lumen Surface (different from the Applicator Surface) the diameter of the (bronchus) lumen has to be reported, which is from ~18mm for the trachea to ~9mm for the tertiary bronchi (for details of the dimensilons and the topogrophical anatomy see Fig 26.1; for an example of a calculation with minimum and maximum doses based on Computed Tomography see Fig 5.7). The Length of the Reference Volume (RVL) is defined as the length of the 90%-isodose at the reference depth of 5 mm.