INTENSITY MODULATED RADIATION THERAPY (IMRT) WITH COMBINED ROTATIONAL AND FIXED MULTI-PORT IRRADIATION (CUTTING FIELD IMRT)
(Received 31 January 2003, accepted 25 June 2003)
Background and purpose: To achieve the dose distribution corresponding to that in IMRT
using a conventional irradiation method, we propose the combination of
rectangular rotation irradiation and fixed multiport irradiation (cutting field
Materials and methods: One rectangular rotational irradiation port was set at which the dose was set to almost half the prescribed dose. Then, 6-10 fixed ports were set. The number of ports or dose weight was relatively large on the posterior side. When hot points appeared, MLC was cut in the most effective direction (cutting field).
Results: Highly conformed plans were made in all clinical cases with reduced radiation doses of OARs. Most plans were made within 30 minutes. RCI was about 0.9 in most cases. Most of the hot points disappeared after adjusting the dose weight and beam orientation.
Conclusions: This method employs conventional technology, so it can be used in a large number of facilities. Each plan was easily made in a comparatively short time even by forward planning. The method can be applied to inverse planning in any area because various templates can be easily fabricated.
Key words: Conformal, IMRT, Fixed port, Radiation
last modification date: 2014/08/15