CT based 3D planning of craniospinal radiotherapy

CT-based 3D treatment planning has been utilized clinically at our Centre since 1995. To date 3003 patients have been planned using this system. 110 of them had primary Central Nervous System malignancies. Among them, four patients were planned for craniospinal radiotherapy (CSR). The CT-based 3D planning process for CSR is described. Dose distributions throughout the treatment volume are superimposed on CT images in different planes. Various 3D planning tools such as dose volume histograms (DVHs), beam eye views (BEVs) and 3D volume rendering (3DVR) were utilized. The approach employed offers several advantages over 2D treatment planning for CSR. This is evident when considering (i) ability to visualize and document dosimetric information in various planes, (ii) ability to assess adequate coverage of critical areas (meninges, cribriform rately document doses delivered to normal tissues (e.g. leplate, optic nerves, etc.), (iii) ability to assess dosimetry at the junctions of adjacent fields, (iv) ability to accunses, thyroid, eosophagus, lungs, gonads, etc.). Our initial experience has demonstrated that 3D treatment planning is the preferred approach to planning of CSR in a state-of-the-art environment. There is great potential for use of this tool in modification and improvement of current treatment techniques.