Effect of optimizing clinical target volume in neck node levelⅣon thyroid dose in nasopharyngeal carcino-ma
CHEN Wei
WANG Lijun
WANG Feijiang
HUANG Shengfu
HE Xia
ZHANG Yiqin
Abstract：Objective To assess the effect of optimizing the neck node levelⅣin IMRT clinical target volume( CTV) for na?sopharyngeal carcinoma( NPC) on the treatment outcome and thyroid dose, in order to provide the basis for optimization of IMRT target area in NPC. Methods For selected 64 cases of NPC patients treated with IMRT,including 32 cases of neck node level Ⅳ region which optimized,and a control group of 32 cases which Ⅳ region is still within the CTV; Radiation dose parameters of thyroid were measured using treatment plan system for all patients. These radiation dose parameters of thyroid were compared between optimization and no optimization groups,as well as among different clinical stages, T and N stages, respectively. Meanwhile, a survival analysis was performed using Kaplan?Meier method. Results Reasonably optimizing the neck node levelⅣin CTV can significantly reduce the thy?roid mean dose and volume percent dose V50( P<0?05) and does not decrease the local control probability. The thyroid mean dose and V50 of patients with stageⅣwere much higher than those with other stages, and for the N0?2 patients, optimization of neck node levelⅣin CTV can significantly reduce the thyroid mean dose and V50 comparing with no optimization group. Conclusion For NPC patients, reasonably optimizing the neck node level Ⅳ in CTV is safe and can much better protect the thyroid gland.
Keywords：Nasopharyngeal neoplasmsIntensity modulated radiotherapyThyroidClinical target volume optimization
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 1023-1027 )