title: Positive clinical impact of an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy in patients with advanced oral cavity squamous cell carcinoma.
abstract: The aim of this single-center study was to investigate whether obtaining an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy (CCRT) could meaningfully improve 2-y disease-free survival (DFS) and disease-specific survival (DSS) rates.
  
  
  METHODS
  Six hundred seventy-four patients with oral cavity squamous cell carcinoma who received adjuvant therapy after radical surgery were included. Of these, 152 patients were initially scheduled to receive an additional preradiotherapy/CCRT PET/CT scan within 1 wk of starting adjuvant therapy. However, 16 patients were excluded because of either medical problems or refusal. Therefore, 136 patients underwent a preradiotherapy/CCRT PET/CT scan (PET group), and 522 did not (NO-PET group). All of the participants were followed up for at least 2 y or censored at the last follow-up. The impact of preradiotherapy/CCRT PET/CT imaging was examined using Kaplan-Meier curves and Cox proportional hazards models.
  
  
  RESULTS
  Two-year DFS (80% vs. 70%, P = 0.033) and DSS (84% vs. 75%, P = 0.010) rates were significantly higher in the PET than in the NO-PET group. In the PET group, both DFS and DSS were higher in patients with negative findings than in those without (88% vs. 22% and 91% vs. 36%, respectively; both P < 0.001). A prognostic scoring system based on the presence of the 2 independent risk factors in the PET group (extracapsular spread and lymphatic invasion) predicted both DFS (P = 0.001 and P < 0.001, respectively) and DSS (P = 0.001 and P < 0.001, respectively). Nineteen patients (14%) had their treatment modified by preradiotherapy/CCRT PET/CT findings. Of these, 15 were treated with curative intent due to the presence of locoregional disease, and 4 received palliative care due to distant metastases. Seven of the 15 patients are currently alive without disease.
  
  
  CONCLUSIONS
  An additional preradiotherapy/CCRT PET/CT scan improves both DFS and DSS in patients with advanced oral cavity squamous cell carcinoma.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.affiliation: Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan yen1110@adm.cgmh.org.tw.
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Biostatistics and Informatics Unit, Clinical Trial Center, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Lan-Yan
authors.initials: LY
authors.lastname: Yang
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan yen1110@adm.cgmh.org.tw.
authors.forename: Tsung-Ying
authors.initials: TY
authors.lastname: Ho
authors.affiliation: Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Kang-Hsing
authors.initials: KH
authors.lastname: Fan
authors.affiliation: Department of Medical Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan; and.
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Shiang-Fu
authors.initials: SF
authors.lastname: Huang
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan yen1110@adm.cgmh.org.tw.
authors.forename: Kai-Ping
authors.initials: KP
authors.lastname: Chang
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ku-Hao
authors.initials: KH
authors.lastname: Fang
authors.affiliation: Department of Diagnostic Radiology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan yen1110@adm.cgmh.org.tw.
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan yen1110@adm.cgmh.org.tw.
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
mesh_terms: D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG PET/CT; adjuvant therapy; oral squamous cell carcinoma