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.
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.
| Original language | English |
|---|---|
| Pages (from-to) | 1239–1247 |
| Journal | European journal of nuclear medicine and molecular imaging |
| Volume | 43 |
| Issue number | 7 |
| Early online date | 28 Dec 2015 |
| DOIs | |
| Publication status | Published - Jul 2016 |