Primary result of early parotid gland carcinomas with optimized target design brachytherapy / 中华放射医学与防护杂志

ABSTRACT

Objective To analyze the feasibility of local target in early parotid carcinoma brachytherapy.Methods The retrospective study collected 14 early parotid gland carcinoma patients during November 2004 and February 2013 at Peking University School and Hospital of Stomatology.All of them proceeded conservative surgery and 125I interstitial brachytherapy postoperatively.According to the different target designs,the patients were divided into two groups as local target group and whole target group.The disease-free survival rate and overall survival rate were analyzed.The target volume,the number of 125I seeds and dose of crisis organs such as mandibular ramus,pharynx constrictor,cervical spinal cord,external auditory canal,middle ear,mastoid in the affected side were compared between two groups.Results After 51-116 months of follow-up,disease-free survival rate and overall survival rate in both groups were 100％.The mean D90 of CTV in local target group was(90.3 ±20.4)Gy,and (104.3 ± 10.1)Gy in whole target group.There was no statistical difference between two groups(P ＞ 0.05),while there were statistical differences in target volume (t =5.003,P ＜ 0.05),which were (9.2 ± 2.4) and (35.1 ± 13.5)cm3 respectively.Mean dose of organs at risk between two groups including mandibular ramus,pharynx constrictor,external auditory canal,middle ear,mastoid and maximal dose of cervical spinal cord in the affected side also had significant differences(t =3.534,4.279,3.034,3.471,7.221,6.103,P ＜0.05).Local target group had less target volume and less dose in organs at risk.Conclusions The conservative surgery combined with local target brachytherapy is feasible for the early low grade parotid gland carcinomas,with acceptable survival rate and less risk in organs at risk.