title: Institutional experience of interstitial brachytherapy for head and neck cancer with a comparison of high- and low dose rate practice.
abstract: OBJECTIVE
  To describe our institutional experience with high dose rate (HDR) interstitial brachytherapy (IBT) compared with previously reported results on the low dose rate (LDR) practice for head and neck cancer.
  
  
  METHODS
  Eighty-four patients with oral cavity (n=70) or oropharyngeal cancer (n=14) were treated with 192Ir HDR-IBT. Seventy-eight patients had stage I or II tumour. The patients treated with IBT alone (n=42) received 39-42 Gy/10-14 fractions (median=40 Gy/10 fractions). With respect to the combination therapy group (n=42), prescription dose comprised of 12-18 Gy/3-6 fractions (median=15 Gy/5 fractions) for IBT and 40-50 Gy/20-25 fractions (median=50 Gy/25 fractions) for external radiotherapy. Brachytherapy was given as 2 fractions per day 6 hours apart with 4 Gy per fraction for monotherapy and 3 Gy per fraction for combination therapy.
  
  
  RESULTS
  Four patients were not evaluable in the analysis of outcome. The primary site relapse rates were 23.8% (10/42) and 68.4% (26/38) in patients treated with IBT alone and combination therapy, respectively (p<0.001). Salvage surgery was performed in 19 patients. The 5-year local control rate was estimated at 62% and the disease-free survival (DFS) rate at 52% for all patients. Local control with respect to T1 and T2 tumours was 84% and 42%, respectively.
  
  
  CONCLUSIONS
  Our present series on HDR-IBT and the previous report on LDR-IBT for head and neck cancer demonstrated similar DFS rates at 5 years (52%). The rate of regional failure in node-negative patients was <20% in both of our series. HDR-IBT offers similar results to LDR-IBT for head and neck cancer.
authors.affiliation: Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi, India E-mail : drpujasahai@gmail.com.
authors.forename: Bidhu Kalyan
authors.initials: BK
authors.lastname: Mohanti
authors.forename: Puja
authors.initials: P
authors.lastname: Sahai
authors.forename: Alok
authors.initials: A
authors.lastname: Thakar
authors.forename: Kapil
authors.initials: K
authors.lastname: Sikka
authors.forename: Suman
authors.initials: S
authors.lastname: Bhasker
authors.forename: Atul
authors.initials: A
authors.lastname: Sharma
authors.forename: Seema
authors.initials: S
authors.lastname: Sharma
authors.forename: Sudhir
authors.initials: S
authors.lastname: Bahadur
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000706:statistics & numerical data*; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate; D055815:Young Adult