Comparison of 4 week accelerated hypofractionated chemoIMRT versus less accelerated schedules in oropharyngeal carcinoma.
New radiotherapy techniques/implementation/QA
We compared efficacy outcomes at a minimum follow-up of 2 years in two historic cohorts of locally advanced oropharyngeal carcinoma patients treated with 4-week (20#) or 5-7 week (25-35#) schedule in a single institution.
Between June 2009 and May 2012 (4 week cohort), patients undergoing chemoIMRT were treated with 55Gy/20# over 25 days, with synchronous carboplatin. From June 2012 to April 2014 (>4 week cohort), patients were treated with either (a) 64Gy/25# over 32 days, (b) 65Gy/30# over 39 days, or (c) 70Gy/35# over 46 days, with synchronous cisplatin or carboplatin. Overall survival, local control, distant control, and freedom from recurrence at 2 years were calculated. The effect of age, T-stage, N-stage, p16 status, smoking status, synchronous chemotherapy agent, use of neoadjuvant chemotherapy, and radiotherapy schedule (4-week vs. >4 week) on outcome was analysed.
131 patients with non-metastatic oropharyngeal carcinoma received radical IMRT with concurrent platinum (4-week, n=70; >4 week, n=61). T stage was found to have a statistically significant effect on overall survival (p=0.02) and local control (p=0.04). p16 status was statistically significantly associated to overall survival (p=0.002). At 2 years, local control (p=0.256), freedom from recurrence (p=0.192), and overall survival (p=0.511) were not statistically different between the 4-week and >4 week cohorts.
Survival and disease control were comparable in oropharyngeal carcinoma patients treated with 4-week or >4 week hypofractionation schedules. Accelerated hypofractionated schedules for radical chemoIMRT in oropharyngeal carcinoma need prospective evaluation.