title: IMRT vs. 2D-radiotherapy or 3D-conformal radiotherapy of nasopharyngeal carcinoma : Survival outcome in a Korean multi-institutional retrospective study (KROG 11-06).
abstract: OBJECTIVE
  We compared treatment outcomes of two-dimensional radiotherapy (2D-RT), three-dimensional conformal radiotherapy (3D-CRT), and intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  In total, 1237 patients with cT1-4N0-3M0 NPC were retrospectively analyzed. Of these, 350, 390, and 497 were treated with 2D-RT, 3D-CRT, and IMRT, respectively.
  
  
  RESULTS
  3D-CRT and IMRT showed better 5-year overall survival (OS) rates (73.6 and 76.7 %, respectively) than did 2D-RT (5-year OS of 59.7 %, all p < 0.001). In T3-4 subgroup, IMRT was associated with a significantly better 5-year OS than was 2D-RT (70.7 vs. 50.4 %, respectively; p ≤ 0.001) and 3D-CRT (70.7 vs. 57.8 %, respectively; p = 0.011); however, the difference between the 2D-RT and 3D-CRT groups did not reach statistical significance (p = 0.063). In multivariate analyses of all patients, IMRT was a predictive factor for OS when compared with 2D-RT or 3D-CRT, as was 3D-CRT when compared with 2D-RT.
  
  
  CONCLUSIONS
  Our study showed that 3D-CRT and IMRT were associated with a better local progression-free survival and OS than was 2D-RT in NPC. IMRT was significantly superior in terms of OS for advanced primary tumors (T3-4).
authors.affiliation: Proton Therapy Center, Research Institute and Hospital, National Cancer Center, 323 Ilsan-ro, 10408, Ilsandong-gu, Goyang-si Gyeonggi-do, Republic of Korea.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Moon
authors.affiliation: Proton Therapy Center, Research Institute and Hospital, National Cancer Center, 323 Ilsan-ro, 10408, Ilsandong-gu, Goyang-si Gyeonggi-do, Republic of Korea. kwancho@ncc.re.kr.
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, 50-1 Yonsei-ro, 03722, Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Chang-Geol
authors.initials: CG
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, 50-1 Yonsei-ro, 03722, Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Ki Chang
authors.initials: KC
authors.lastname: Keum
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, the Catholic University of Korea, 222 Banpo-daero, 06591, Seocho-gu, Seoul, Republic of Korea.
authors.forename: Yeon-Sil
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, 03080, Jongno-gu, Seoul, Republic of Korea.
authors.forename: Hong-Gyun
authors.initials: HG
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, 03080, Jongno-gu, Seoul, Republic of Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, 06351, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Ahn
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, 06351, Gangnam-gu, Seoul, Republic of Korea.
authors.forename: Dongryul
authors.initials: D
authors.lastname: Oh
authors.affiliation: Department of Radiation Oncology, The Catholic University of Korea, College of Medicine, 93 Jungbu-daero, 16247, Paldal-gu, Suwon, Gyeonggi-do, Republic of Korea.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000517:prevention & control*; D015995:Prevalence; D020266:Radiotherapy, Conformal / Q000401:mortality* / Q000706:statistics & numerical data; D050397:Radiotherapy, Intensity-Modulated / Q000401:mortality* / Q000706:statistics & numerical data; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Intensity-modulated radiotherapy; Nasopharyngeal neoplasms; Radiotherapy