King's College London

Research portal

(18)FDG PET/CT to assess response and guide risk-stratified follow-up after chemoradiotherapy for oropharyngeal squamous cell carcinoma

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Pages (from-to)1239–1247
JournalEuropean journal of nuclear medicine and molecular imaging
Volume43
Issue number7
Early online date28 Dec 2015
DOIs
Accepted/In press10 Dec 2015
E-pub ahead of print28 Dec 2015
PublishedJul 2016

King's Authors

Abstract

Purpose To evaluate the use of 18F-FDG PET/CT as the principal
investigation to assess tumour response, to determine the
need for further surgery and to guide follow-up following
radical chemoradiotherapy for stage III/IV oropharyngeal
squamous cell carcinoma (OPSCC).
Methods A retrospective analysis was undertaken in 146 patients
treated at our centre with radical chemoradiotherapy for
OPSCC and who had a PET/CT scan to assess response. According
to the PET/CT findings, patients were divided into
four groups and recommendations: (1) complete metabolic
response (enter clinical follow-up); (2) low-level uptake only
(follow-up PET/CT scan in 12 weeks); (3) residual uptake
suspicious for residual disease (further investigation with or
without neck dissection); and (4) new diagnosis of distant
metastatic disease (palliative treatment options).
Results The initial PET/CT scan was performed at a median of
12.4 weeks (range 4.3 – 21.7 weeks) following treatment.
Overall sensitivity and specificity rates were 92.0 % (74.0 –
99.0 %) and 85 % (77.5 – 90.9 %). Of the 146 patients, 90
(62 %) had a complete response and had estimated 3-year
overall and disease-free survival rates of 91.9 % (85.6 –
98.2 %) and 85.6 % (78.0 – 93.2 %), respectively, 17 (12 %)
had residual low-level uptake only (with two having confirmed
residual disease on subsequent PET/CT, both surgically
salvaged), 30 (21 %) had suspicious residual uptake (12
proceeded to neck dissection; true positive rate at surgery
33 %). HPV-positive patients with reassuring PET/CT findings
had an estimated 3-year progression-free survival rate of
91.7 % (85.2 – 98.2 %), compared with 66.2 % (41.5 –
90.9 %) of HPV-negative patients.
Conclusion A strategy of using PET/CT results alongside
clinical examination to help select patients for salvage surgery
appears successful. Despite a complete response on the 12-
week PET/CT scan, HPV-negative patients have a significant
risk of disease relapse in the following 2 years and further
studies to assess whether surveillance imaging in this group
could improve outcomes are warranted.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454