title: Local control in advanced cancer of the nasopharynx: is a boost dose by endocavitary brachytherapy of prognostic significance?
abstract: OBJECTIVE
  To analyze whether local tumor control in advanced nasopharyngeal cancer (NPC) can be optimized by boosting the primary dose by endocavitary brachytherapy (EBT).
  
  
  METHODS
  To study the role of EBT, three data sets on NPC, that is, the "Vienna", "Rotterdam," and "Amsterdam" series, with a total number of 411 advanced NPC patients, were available. The Rotterdam series consisted of 72 patients (34 T1,2N+ and 38 T3,4N0,+) and were treated with neoadjuvant chemotherapy followed by external beam radiotherapy (dose 70/2Gy). After 70/2Gy, a boost was applied by EBT (in case of T1,2N+) or stereotactic radiation (in case of T3,4 tumors). The Amsterdam (Antoni van Leeuwenhoek Hospital/The Netherlands Cancer Institute) series consisted of 76 patients (40 T1,2N+ and 36 T3,4N0,+) and were irradiated to a dose of 70/2Gy with concomitant chemotherapy. No second boost by EBT was applied.
  
  
  RESULTS
  In the case of T1,2N+ tumors, the local relapse rate (LRR) was significantly smaller if a boost was applied, that is, 0% (0/34, EBT boost) vs. 14% (14/102, no EBT boost) (p=0.023). For the T3,4 tumors, an LRR of 10% (4/38, EBT or stereotactic radiation boost) vs. 15% (17/111, no boost) was found (p=0.463).
  
  
  CONCLUSIONS
  In the case of advanced NPC (T1,2N+ vs. T3,4N+,0), for early T-stages (T1,2N+), an EBT boost seems an excellent way to deliver highly conformal high doses of radiation to the nasopharynx, with high local control rates. For advanced T-stages (T3,4N+,0), the reduction in LRR (10% vs. 15%) was not significant (p=0.463).
authors.affiliation: Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands. p.levendag@erasmusmc.nl
authors.forename: Peter C
authors.initials: PC
authors.lastname: Levendag
authors.forename: Fatma
authors.initials: F
authors.lastname: Keskin-Cambay
authors.forename: Connie
authors.initials: C
authors.lastname: de Pan
authors.forename: Marjolein
authors.initials: M
authors.lastname: Idzes
authors.forename: Maarten A
authors.initials: MA
authors.lastname: Wildeman
authors.forename: Inge
authors.initials: I
authors.lastname: Noever
authors.forename: Inger-Karine
authors.initials: IK
authors.lastname: Kolkman-Deurloo
authors.forename: Abrahim
authors.initials: A
authors.lastname: Al-Mamgani
authors.forename: M
authors.initials: M
authors.lastname: El-Gantiry
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rosenblatt
authors.forename: David N
authors.initials: DN
authors.lastname: Teguh
mesh_terms: D001317:Austria / Q000453:epidemiology; D019583:Dose Fractionation, Radiation; D006801:Humans; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000532:radiotherapy*; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D011878:Radiotherapy; D020266:Radiotherapy, Conformal / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data*; D016896:Treatment Outcome