Abstract：Objective To explore the best optimization parameters of IMRT in field junction. Methods Nine patients who need field
junction received 36 treatment plans, including 1, 2, 4, 8 cm overlying-field region. Plan A and plan B were optimized together,
and the isocenters moved 3, 5 and 10 mm at the directions of head and foot to simulate and analyze the influences of setup errors
and overlying-field lengths on the dose distribution of the target. In order to assure a ramp-like dose profile in the field overlap
region, the plan A was optimized first, with dose prescription explicitly enforcing a ramp-like dose profile. The plan B was done
afterwards, taking into account the dose contribution of the plan A. Results The shorter the overlying-field length, the worse the
dose distribution of the target, without considering the setup errors (F=144.890 and 7.878, P<0.05), which was the same when
considering the setup errors (F=34.887 and 37.403, P<0.05). A linear ramp-like dose profile in treatment field overlap regions could
improve treatment plan robustness with respect to small shifts in patient position during the IMRT treatment (t=9.974 and 5.357,
P<0.05). Conclusion The IMRT plans with the overlying-field length ≥4 cm and ramp-like dose profile can minimize dosimetric
dependence on minor positional errors in patient set-up.
李彩虹，王沛沛，李金凯，昌志刚，顾宵寰，孙新臣. 调强放疗技术在射野衔接中的应用研究[J]. 中国医疗设备, 2018, 33(8): 66-69.
LI Caihong, WANG Peipei, LI Jinkai, CHANG Zhigang, GU Xiaohuan, SUN Xinchen. Study on the Application of Intensity Modulated Radiotherapy in Field Junction. China Medical Devices, 2018, 33(8): 66-69.
