Fig. 1From: Collimator rotation in volumetric modulated arc therapy for craniospinal irradiation and the dose distribution in the beam junction regionMLC conformed to a long target at 0° and 45° collimator angles. a, b collimator cannot conform well to the target of 36 cm long at 45°; c, d 48 cm long target divided into two parts of 24 cm in length; d the lower half of the target is conformed well with the collimator at 45°Back to article page