直线加速器污染物的磁排斥

Magnetic repulsion of linear accelerator contaminates.

作者信息

Butson M J, Wong T P, Law A, Law M, Mathur J N, Metcalfe P E

机构信息

Illawarra Cancer Care Centre, Department of Radiotherapy, Wollongong NSW, Australia.

出版信息

Med Phys. 1996 Jun;23(6):953-5. doi: 10.1118/1.597818.

DOI:10.1118/1.597818

PMID:8798165

Abstract

Neodymium Iron Boron (NdFeB) rare earth permanent magnets have unique properties that enable them to fit easily onto the accessory mount of a clinical linear accelerator to partially sweep away electron contamination produced by the treatment head and block trays and thus increase skin sparing. Using such magnets the central axis entrance surface dose has been reduced by 11% for a 20 x 30 cm field size from 32% to 21% of maximum dose by the magnetic device. A reduction of 14% from 32% to 18% was seen for a 20 x 20 cm field size with a 6 mm perspex block tray positioned above the magnet. The magnetic device is light weight and thus clinically usable.

摘要

钕铁硼（NdFeB）稀土永磁体具有独特的性能，使其能够轻松安装在临床直线加速器的附件支架上，部分清除治疗头和挡块托盘产生的电子污染，从而增加皮肤保护。使用这种磁体，对于20×30 cm的射野尺寸，中心轴入射表面剂量从最大剂量的32%降低到21%，降低了11%。对于20×20 cm的射野尺寸，在磁体上方放置一个6 mm有机玻璃挡块托盘时，剂量从32%降低到18%，降低了14%。该磁体装置重量轻，因此在临床上可用。