title: A versatile electron collimation system to be used with electron cones supplied with Varian's Clinac 18.
mesh_terms: D000497:Alloys; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy*; D011835:Radiation Protection / Q000295:instrumentation*; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D013679:Technology, Radiologic / Q000295:instrumentation*
chemical_list: D000497:Alloys