Consensus on 3D treatment planning in gynaecologic brachytherapy of the Radiation Oncology Spanish Society (SEOR) Brachytherapy Group.

Gynaecologic brachytherapy (BT) is a fundamental part of the treatment of gynaecologic carcinomas, especially if it is not possible to perform surgery. Traditionally, low-dose-rate BT and planning by orthogonal X-rays have been used. Nowadays, high-dose-rate BT is available in most centres, enabling it to enhance the dose optimisation, radiation protection and comfort of patients. Technical advantages in image and dosimetry have enabled the switch to CT and MRI as a means to define the tumour and the organs at risk, and to perform realistic anatomical-based planning. However a general consensus about the way the dose should be prescribed has not yet been reached. Some centres still use the Manchester points A as the reference to specify the dose. It was imperative to work towards a consensus and for this reason the VII Consensus Meeting of the Radiation Oncology Spanish Society (SEOR) Brachytherapy Group was organised. We agreed that some imaging system, CT or MRI, rather than the traditional system with orthogonal X-rays, should always be used for treatment planning. The dose should be prescribed by volume instead of points. And the given dose should be reported by adding external beam radiotherapy dose and BT dose as EQD2 (isoeffective dose). Caution is also recommended in changing the mode of planning and prescription, taking into account previous experience with points A.