title: Hypertrophic adenoids in patients with nasopharyngeal carcinoma: appearance at magnetic resonance imaging before and after treatment.
abstract: BACKGROUND
  Patients with nasopharyngeal carcinoma (NPC) sporadically develop abnormal adenoids. Nasopharyngeal adenoids are usually included in the gross tumor volume (GTV) but may have different therapeutic responses than tumor tissue. Therefore, distinguishing adenoids from tumor tissue may be required for precise and efficient chemoradiotherapy and radiotherapy. We characterized nasopharyngeal adenoids and investigated the therapeutic responses of NPC and nasopharyngeal adenoids using magnetic resonance imaging (MRI).
  
  
  METHODS
  MRI data from 40 NPC patients with a coexisting adenoid mass before and after treatment were analyzed. The features of the adenoid masses, including location, striped appearance, size, interface, symmetry/asymmetry, and cysts, were evaluated. Treatment response were scored according to the World Health Organization guidelines.
  
  
  RESULTS
  A striped appearance was observed in 36 cases before treatment and in all cases after treatment. In these 36 cases, the average GTVs including and excluding the uninvolved adenoids were 19.8 cm³ and 14.8 cm³, respectively. The average percentage change after excluding the uninvolved adenoids from the GTV was 31.0%. Stable disease in the adenoids was identified in 27 (96.4%) of 28 patients after neoadjuvant chemotherapy, while NPC clearly regressed. Partial adenoid responses were identified in 33 (82.5%) of 40 patients at 3 months after chemoradiotherapy or radiotherapy, whereas complete tumor responses were achieved in all patients. Six months after treatment, the adenoids continued to atrophy but did not disappear, and tumor recurrence was not found.
  
  
  CONCLUSIONS
  Nasopharyngeal adenoids and carcinoma tissue in NPC patients can be distinguished by using MRI and have different responses to chemoradiotherapy and radiotherapy. These findings contribute to better delineating the GTV of NPC, based on which spatially optimized strategies can be developed to render precise and efficient chemoradiotherapy and radiotherapy. Additionally, we observed a clear difference in the responses of these two tissue types to current therapies. This finding may reduce or avoid unnecessary biopsies or overtreatment.
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. yaopanwu@163.com.|Center of Medical Imaging & Image-guided Therapy, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou, Guangdong, 510060, P. R. China. yaopanwu@163.com.
authors.forename: Yao-Pan
authors.initials: YP
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. caipq@sysucc.org.cn.|Center of Medical Imaging & Image-guided Therapy, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou, Guangdong, 510060, P. R. China. caipq@sysucc.org.cn.
authors.forename: Pei-Qiang
authors.initials: PQ
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. tianli@sysucc.org.cn.|Center of Medical Imaging & Image-guided Therapy, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou, Guangdong, 510060, P. R. China. tianli@sysucc.org.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.affiliation: Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, P. R. China. xujhgz3@163.com.
authors.forename: Jie-Hua
authors.initials: JH
authors.lastname: Xu
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA, 19104, USA. mitteerr@uphs.upenn.edu.
authors.forename: Richard Alan
authors.initials: RA
authors.lastname: Mitteer
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA, 19104, USA. yi.fan@uphs.upenn.edu.
authors.forename: Yi
authors.initials: Y
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China. zhangzhf@sysucc.org.cn.|Center of Medical Imaging & Image-guided Therapy, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou, Guangdong, 510060, P. R. China. zhangzhf@sysucc.org.cn.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000234:Adenoids; D001706:Biopsy; D002277:Carcinoma; D059248:Chemoradiotherapy; D057186:Comparative Effectiveness Research; D006801:Humans; D008279:Magnetic Resonance Imaging; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms; D009305:Nasopharynx; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local; D012074:Remission Induction; D016896:Treatment Outcome