Initial work-up and selection
Decision to offer PBTin each of the patients was taken after a thorough evaluation and discussion in the multidisciplinary tumor board. Patients were referred from all over the country as well as from adjoining regions. Our criteria included patients eligible for only radical intent treatmentrequiring relatively high doses of radiation orwithtumors located adjacent toradiosensitive structures making them prone to late radiation sequelae or had required magna-field irradiation were recommended PBT. Patients requiring whole organ irradiation were not chosen for PBT except in patients receiving craniospinal irradiation (CSI). In certain cases, a dosimetric plan was generated before a decision to treat with PBT was taken.
A few days prior to the day of simulation, younger children (<10 years old), were encouraged to visit the treatment facility to view treatments of other children to familiarize the procedure and reduce anxiety.All patients underwent a simulation procedure (with or without sedation) consisting of immobilization and multimodality imaging (CT and MRI of the site to be treated) nearly a week before the decided day of starting treatment.