A novel supine isocentric approach for craniospinal irradiation and its clinical outcome

Objective:To report a novel approach for craniospinal irradiation (CSI) using a supine isocentric technique.Methods:Patients were treated in the supine position using CT simulation. Half-beam-blocked lateral cranial fields and superior spinal fields have the same isocentre, and their beam divergences match. Tangential irradiation provides a non-divergent junction for the other two full-beam spinal fields. Shielding for cranial fields was generated, and dose distribution was calculated using a three-dimensional planning system. When sacral spinal fields were required, two lateral opposite fields were designed to protect the urogenital organs. All treatment portals were filmed once per week.Results:At a median follow-up of 49.8 months, 5 relapses and no cases of radiation myelitis developed in 26 consecutive patients. In the junctions of the brain–spine or spine–spine field, no failure occurred. Three failures occurred in the primary site alone, two in the spinal axis alone.Conclusion:The results of our stu...