title: Postoperative simultaneous integrated boost-intensity modulated radiation therapy for patients with locoregionally advanced papillary thyroid carcinoma: preliminary results of a phase II trial and propensity score analysis.
abstract: BACKGROUND
  With recent technical advances in radiotherapy (RT) planning, simultaneous integrated boost intensity modulated radiotherapy (SIB-IMRT) has made possible the delivery of high radiation dose to the tumor, minimizing surrounding normal tissues.
  
  
  OBJECTIVE
  This study aimed to evaluate the clinical effectiveness and safety of postoperative SIB-IMRT in patients with locoregionally advanced papillary thyroid cancer (PTC).
  
  
  METHODS
  This was a propensity score-matched case control study conducted at a tertiary referring center.
  
  
  METHODS
  This study included locoregionally advanced patients with PTC (pT4 or N1b) who underwent thyroid cancer surgery and radioactive iodine ablation (RIA) followed by postoperative SIB-IMRT (RT group) under a phase II trial or no postoperative RT (Non-RT group) Intervention: Postoperative SIB-IMRT was the intervention.
  
  
  METHODS
  locoregional relapse-free survival (LRFS) was compared between RT group and Non-RT group.
  
  
  RESULTS
  Multivariate analysis showed that several factors, including sex, American Thyroid Association risk category, and use of postoperative RT were significantly associated with LRFS in all 201 patients (P < .05 each). In the 118 propensity score-matched patients, there were no significant differences in baseline characteristics between the RT and Non-RT groups, but the LRFS rate was significantly higher in the RT than in the Non-RT group (4 y: 100% vs 84.6%, P = .002). Overall, SIB-IMRT was well tolerated, with no grade ≥3 toxicity, and was completed as planned in all patients.
  
  
  CONCLUSIONS
  Postoperative SIB-IMRT is feasible and effective in improving locoregional control in patients with locally advanced PTC. Large-scale randomized studies are warranted.
authors.affiliation: Center for Thyroid Cancer, Research Institute and Hospital (E.K.L., Y.J.L., Y.J., J.R., T.H.K., C.Y.L., C.H.R., T.S.K., S.K.K., K.W.C., S.S.K., D.Y.K., J.Y.K., K.H.C.), National Cancer Center, Goyang, 410-769, Republic of Korea; and Department of Surgery (K.W.C.), Asan Medical Center, Seoul, 138-736, Rupublic of Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Lee
authors.forename: You Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Yuh-S
authors.initials: YS
authors.lastname: Jung
authors.forename: Junsun
authors.initials: J
authors.lastname: Ryu
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.forename: Chang Yoon
authors.initials: CY
authors.lastname: Lee
authors.forename: Chang Hwan
authors.initials: CH
authors.lastname: Ryu
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Kim
authors.forename: Seok Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Ki-Wook
authors.initials: KW
authors.lastname: Chung
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Joo Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002291:Carcinoma, Papillary; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011184:Postoperative Period; D057216:Propensity Score; D050397:Radiotherapy, Intensity-Modulated; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult