D Mak MBBS, FRANZCR; RJ Hicks MBBS, MD, FRACP; D Rischin MBBS, MD, FRACP; B Solomon MBBS, PhD; L Peters MD, FRANZCR; M Bressel MSc; RJ Young BSc (Hons); J Corry FRANZCR, MD.
Radiation Oncology—Original Article
Treatment response in the neck: p16+ versus p16− oropharyngeal cancer
Article first published online: 30 JAN 2013
© 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists
Journal of Medical Imaging and Radiation Oncology
Volume 57, Issue 3, pages 364–372, June 2013
How to Cite
Mak, D., Hicks, R. J., Rischin, D., Solomon, B., Peters, L., Bressel, M., Young, R. J. and Corry, J. (2013), Treatment response in the neck: p16+ versus p16− oropharyngeal cancer. Journal of Medical Imaging and Radiation Oncology, 57: 364–372. doi: 10.1111/1754-9485.12024
Conflict of interest: No conflict of interest.
- Issue published online: 31 MAY 2013
- Article first published online: 30 JAN 2013
- Manuscript Accepted: 5 OCT 2012
- Manuscript Received: 22 MAR 2012
- oropharyngeal cancer;
- treatment response
To compare nodal response rates following chemoradiotherapy in patients with p16+ and p16− oropharyngeal squamous cell carcinoma (OPSCC).
Patients with node-positive OPSCC treated at Peter MacCallum Cancer Centre on the published phase I–III tirapazamine trials were identified. All patients had conventional assessment (clinical examination (CA), CT and/or MRI) and positron emission tomography (PET) at both baseline and 2–4 months post-treatment.
There were 30 p16+ and 18 p16− patients, the former group having significantly higher stage nodal disease (P = 0.016). The mean overall reduction in nodal size at post-treatment assessment was similar in p16+ and p16− patients (78% vs. 75%), and no statistically significant difference in nodal complete response (CR) rates was detected by either CA (50% vs. 39%, P = 0.35) or PET/PET-CT (93% vs. 83%, P = 0.19). PET was significantly more accurate in determining the true nodal CR rate in both groups, with a negative predictive value of 96%.
Nodal response rates following chemoradiotherapy appear to be similar in p16+ and p16− patients when assessed by either CA or PET/PET-CT. However, higher nodal CR was seen in PET/PET-CT compared with CA in both groups. Metabolic imaging is more accurate than CA in assessing nodal response post-treatment.