Development and evaluation of a new technique in three-dimensional conformal radiotherapy (3D-CRT) for craniospinal axis radiotherapy planning

Abstract

A new technique for craniospinal irradiation (CSI) was developed in three-dimensional conventional radiotherapy (3D-CRT) using a half beam and a field in field (FIF) to improve dose distribution in the planning target volume (PTV) and to reduce the dose of organs at risk (OARs). This technique was evaluated by comparing it with conventional technique through studying the dose volume histograms (DVHs), in addition to calculate the quality indexes and dose of the OAR.

The new technique reduced the maximum dose in the overlap fields junction area to 107% of the prescribed dose. It also increased the minimum dose of spinal curvature to 87.8%. it significantly improved the homogeneity index values (-40 ± 13.1%) and the conformity index (11.8 ± 4.2). A significant reduction of maximum dose was observed in the liver, stomach and bowel (p < 0.05). The results of this study showed the importance of using new technique in the radiotherapy planning systems for craniospinal irradiation (CSI) because they have a significant role in achieving more homogeneous dose distribution along PTV with less radiation dose for OAR.