Collimator rotation in volumetric modulated arc therapy for craniospinal irradiation and the dose distribution in the beam junction region

Table 3 The specification of the treatment plans

^aThere were 2 beam isocenters in this study
^bThe patient whose PTV was 80.7 cm long was excluded for PAc0c0 and PAc45c45
^cThere were six partial arc beams with lower isocenter when there was 45 collimator angle. The target covered by the beams with the lower isocenter was divided into two parts then the beams conformed to them respectively

ISSN: 1748-717X