title: A comparative analysis between sequential boost and integrated boost intensity-modulated radiation therapy with concurrent chemotherapy for locally-advanced head and neck cancer.
abstract: BACKGROUND
  Planning and delivery of IMRT for locally advanced head and neck cancer (LAHNC) can be performed using sequential boost or simultaneous integrated boost (SIB). Whether these techniques differ in treatment-related outcomes including survival and acute and late toxicities remain largely unexplored.
  
  
  METHODS
  We performed a single institutional retrospective matched cohort analysis on patients with LAHNC treated with definitive chemoradiotherapy to 69.3 Gy in 33 fractions. Treatment was delivered via sequential boost (n = 68) or SIB (n = 141). Contours, plan evaluation, and toxicity assessment were performed by a single experienced physician. Toxicities were graded weekly during treatment and at 3-month follow up intervals. Recurrence-free survival, disease-free survival, and overall survival were estimated via Kaplan-Meier statistical method.
  
  
  RESULTS
  At 4 years, the estimated overall survival was 69.3% in the sequential boost cohort and 76.8% in the SIB cohort (p = 0.13). Disease-free survival was 63 and 69% respectively (p = 0.27). There were no significant differences in local, regional or distant recurrence-free survival. There were no significant differences in weight loss (p = 0.291), gastrostomy tube placement (p = 0.494), or duration of gastrostomy tube dependence (p = 0.465). Rates of acute grade 3 or 4 dysphagia (82% vs 55%) and dermatitis (78% vs 58%) were significantly higher in the SIB group (p < 0.001 and p = 0.012 respectively). Moreover, a greater percentage of the SIB cohort did not receive the prescribed dose due to acute toxicity (7% versus 0, p = 0.028).
  
  
  CONCLUSIONS
  There were no differences in disease related outcomes between the two treatment delivery approaches. A higher rate of grade 3 and 4 radiation dermatitis and dysphagia were observed in the SIB group, however this did not translate into differences in late toxicity. Additional investigation is necessary to further evaluate the acute toxicity differences.
authors.affiliation: Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, USA. gvlacich@wustl.edu.|Current affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4291 Parkview Place, Campus Box 63110, St. Louis, MO, 63110, USA. gvlacich@wustl.edu.
authors.forename: Gregory
authors.initials: G
authors.lastname: Vlacich
authors.affiliation: Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Stavas
authors.affiliation: School of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Praveen
authors.initials: P
authors.lastname: Pendyala
authors.affiliation: Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Shaeu-Chiann
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shyr
authors.affiliation: Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, USA.|Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Cmelak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy / Q000379:methods*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies
keywords: Acute toxicity; Intensity modulated; Radiotherapy; Sequential boost; Squamous cell carcinoma of the head and neck