Feasibility of Dose-escalated Hypofractionated Chemoradiation in Human Papilloma Virus-negative or Smoking-associated Oropharyngeal Cancer.

AIMS: Oropharyngeal squamous cell carcinoma (OPSCC) can be divided into favourable and poor prognostic groups by association with human papilloma virus (HPV) and smoking. This study prospectively investigated a dose-intensified schedule in poor/intermediate prognosis OPSCC. MATERIALS AND METHODS: Patients with p16/HPV-negative or p16-positive N2b OPSCC with a greater than 10 pack-year smoking history were eligible. Patients were planned to receive 64 Gy in 25 fractions with cisplatin. The primary end point was absence of grade 3 mucositis at 3 months. RESULTS: Fifteen patients were recruited over 14 months. All patients completed a minimum of 2 years of follow-up. All patients completed full-dose radiotherapy within a median treatment time of 32 days (31-35). Grade 3 mucositis was absent in all patients at 3 months. There was one grade 4 toxicity event due to cisplatin (hypokalaemia). Complete response rates at 3 months were 100% and 93% for local disease and lymph nodes, respectively. One patient developed metastatic disease and subsequently died. Overall survival at 2 years was 93% (95% confidence interval 61-99%). CONCLUSIONS: The schedule of 64 Gy in 25 fractions with concomitant chemotherapy is tolerable in patients with poor and intermediate prognosis OPSCC.

Changes in Patterns of Intensity-modulated Radiotherapy Verification and Quality Assurance in the UK.

AIMS: Between 2012 and 2014 the number of patients treated in the UK with intensity-modulated radiotherapy (IMRT) techniques increased significantly. One reason for this was the radiotherapy innovation fund for the centres in England. Before the announcement of the fund, a survey of radiotherapy centres was carried out in 2012 which collected data on IMRT uptake, obstacles to implementation, equipment used, delivery techniques and verification methods. A repeat survey was carried out in 2014 to identify key changes to IMRT quality assurance and verification practices. MATERIALS AND METHODS: An online questionnaire was sent out to all 65 UK radiotherapy centres in the summer of 2012 and again in the summer of 2014. Questions covered background and equipment, machine tolerance and quality assurance, machine-based verification, software-based verification and future plans. RESULTS: There have been significant changes in the delivery techniques used for IMRT, with more than twice as many centres reporting the use of volumetric-modulated arc therapy techniques in 2014 compared with 2012. This has been combined with an increase in Monte Carlo-based algorithms in treatment planning systems. In 2012 all centres reported the need to carry out machine-based measurements for IMRT plan verification, dropping to 93% in 2014. Nineteen per cent of centres now report making only one measurement per month for prostate plans and 8% of breast plans never have physical measurements. Most centres use detector arrays for quality assurance measurement (86% in 2012 and 91% in 2014), but a significant number still use film and/or ionisation chambers (51% and 41%). In the analysis of these measurements there has been an increase in the use of tighter criteria. There has been a significant increase in the use of software for verification from 63% in 2012 to 95% in 2014. All centres reported that they needed further resources in order to efficiently achieve the quality assurance required for the number of patients planned to be treated in their centre. CONCLUSIONS: The increased numbers of patients being treated with IMRT has meant that there have been significant changes in the way that quality assurance is carried out. These have been mainly in the reduction of measurements and the increase in software-based verification. However, quality assurance is still a significant burden and still has an effect on the numbers of patients who can be treated with IMRT.