9 Reporting in Brachytherapy: Dose and Volume Specification

200 Reporting in Brachytherapy

8.4 Volumes for reporting and their dimensions 8.4.1 Treated Volume 8.4.1.1 Definition

The Treated Volume is the pear and banana shape volume that received (at least) the dose selected and specified by the radiation oncologist as being appropriate to achieve the purpose of the treatment, e.g., tumour eradication or palliation, within the limits of acceptable complications (Fig 6.27, 6.28) [43]. 8.4.1.2 Recommendations for reporting The 3 dimensions (Fig 6.27) of the Treated Volume should be reported separately as well as its actual volume. Reporting the product of the 3 orthogonal dimensions of the Treated Volume could be misleading and is not recommended. The dose level selected to define the Treated Volume can be reported: -as the prescribed dose, in absolute dose value (in Gy), and/or -as a percentage of the dose delivered at reference points selected for prescribing and/or reporting. Two additional volumes may be defined, related to the Treated Volume 8.4.1.3 High-dose volume Recording and reporting the volume encompassed by the isodose corresponding to 150% (and 200 %) of the dose defining the Treated Volume may be useful for interpretation of tumour effects, side effects and for purpose of comparison. However, this high-dose volume is probably less relevant than in interstitial therapy, since a large part of this volume lies within the applicator itself and the other part corresponds to radioresistant cervical and uterine tissue. 8.4.1.4 Irradiated volume The irradiated volumes are the volumes, surrounding the Treated Volume, encompassed by a lower isodose to be specified, e.g., 90 – 50% of the dose defining the Treated Volume. Reporting irradiated volumes may be useful for interpretation of side effects outside the Treated Volume and for purpose of comparison. 8.4.2 Point A volume 8.4.2.1 Definition The tissue volume (dimensions and actual volume) encompassed by the isodose level corresponding to the dose at point A is recommended for reporting in the present report: dimensions and actual volume (Fig 6.27, 6.28) 8.4.2.2 Recommendations for reporting

Dimensions should be reported as indicated in Fig 6.27.