Overview of the clinical effectiveness of
positron emission tomography imaging
in selected cancers
K Facey,1*I Bradbury,2G Laking3and E Payne4
1 Evidence Based Health Policy Consultant, Drymen, UK
2 Epidemiology and Public Health, Queen’s University of Belfast, UK
3 Department of Nuclear Medicine, Auckland City Hospital, New Zealand
4 Information Specialist, Salisbury, UK
* Corresponding author
Health Technology Assessment
NHS R&D HTA Programme
Health Technology Assessment 2007; Vol. 11: No. 44
Positron emission tomography imaging in
Staging the extent of disease in primary or
recurrent cancer requires a range of diagnostic
tests to identify the primary tumour and any
metastases. Most of the imaging methods are
anatomical, e.g. computed tomography (CT).
Positron emission tomography using 2-[18F]-
fluoro-2-deoxy-D-glucose (FDG-PET) is an
alternative form of diagnostic imaging based on
tissue function, which can help to identify active
tumours. This health technology assessment
evaluates the use of FDG-PET in eight cancers. It
encompasses both dedicated PET and newer
PET/CT technology that integrates PET and CT
into one device.
The aim of this review was to assess the clinical
effectiveness of FDG-PET in breast, colorectal,
head and neck, lung, lymphoma, melanoma,
oesophageal and thyroid cancers. For each cancer,
use of FDG-PET to aid management decisions
relating to diagnosis, staging/restaging,
recurrence, treatment response and radiotherapy
(RT) planning were evaluated.
This report augments the systematic search
undertaken in a previous rapid review. It uses a
systematic search undertaken in August 2005 that
identified systematic reviews and primary studies
not included in the previous review and a survey of
UK PET facilities performed in February 2006.
Studies were limited to those using commercial
dedicated PET or PET/CT devices with FDG, in
one of the eight cancers. The most recent robust
systematic reviews were identified, along with
additional primary studies that were prospective
and included at least 12 patients. Treatment
response and RT planning studies were included if
they had at least six patients and for PET/CT
retrospective studies were included. All selections
were made by two researchers independently using
predefined inclusion criteria.
Data extraction forms were created for each study
to identify key features of study design and conduct
according to the Quality Assessment of Studies of
Diagnostic Accuracy (QUADAS) quality checklist.
Given the variety of methods used in the
individual publications, the evidence has been
summarised in qualitative form.
From this new search, six systematic reviews and
158 primary studies were included in the
An English economic model shows that in non-
small cell lung cancer (NSCLC) FDG-PET was cost-
effective in CT node-negative patients, but not in
CT node-positive patients. There is some evidence
to suggest that FDG-PET may also be cost-effective
in RT planning, but this model is less robust.
A Scottish model shows that in late-stage
Hodgkin’s lymphoma (HL), FDG-PET was cost-
effective for restaging after induction therapy.
For staging/restaging colorectal cancer, FDG-PET
changed patient management in a way that can
impact on curative therapy.
For detection of solitary pulmonary nodule (SPN)
there is evidence of impact on patient management,
but the impact on patient outcomes is unclear.
FDG-PET had an impact on patient management
across paediatric lymphoma decisions, but further
study of individual management decisions is
required. For other cancer management decisions,
the evidence on patient management is weak.
FDG-PET was accurate in detecting distant
metastases across several sites, but sensitivity was
Executive summary: Positron emission tomography imaging in selected cancers
variable for detection of lymph-node metastases and
poor in early-stage disease, where sentinel lymph-
node biopsy would be used and for small lesions.
FDG-PET had improved diagnostic accuracy over
● colorectal recurrence
● detection of occult and synchronous head and
neck tumours, where other tests have failed
● staging regional lymph nodes in clinically
● restaging/recurrence in head and neck
● staging SCLC
● staging lymphoma
● restaging NHL
● staging oesophageal
● recurrent epithelial thyroid cancer, where
elevated biomarkers are not confirmed by
Some evidence of the diagnostic accuracy of
FDG-PET exists for the following cancers, but
more comparative evidence is needed:
● locoregional recurrence in breast
● staging/restaging/recurrence in breast
● staging lymph nodes in colorectal cancer
● diagnosis of occult SCLC
● staging late-stage melanoma
● recurrent melanoma
● restaging thyroid
● recurrent medullary thyroid cancer, where
elevated biomarkers are not confirmed by
● clinically suspected recurrent thyroid cancer
with no other markers.
Treatment response/RT planning
There were 61 studies of treatment response in all
cancers except for melanoma. Most studies were
small and evaluated a range of treatments, at
different time-points, with a variety of imaging
processes and analytical techniques. They showed
that FDG-PET imaging could be correlated with
response, in some cases, but the impact on patient
management was not documented.
There were 17 small studies on RT planning in
four cancers. FDG-PET led to alteration of RT
volumes and doses, but the impact on patient
outcomes was not studied.
There were 23 studies of PET/CT in six cancers
(excluding breast and melanoma). Most studies
combined different groups of patients to assess
primary and recurrent tumours for staging and
restaging. These showed that FDG-PET/CT
generally improved accuracy by 10–15% over PET,
resolving some equivocal images.
The survey of PET facilities in the UK showed that
PET and PET/CT are being used for a variety of
cancer indications. The distribution of PET
facilities is not evenly spread across the UK and
uses are not consistent. FDG deliveries are often
required twice a day and most units use a
commercial provider. Various research studies are
underway in most centres, but only a few of these
are collaborative studies. There is major variation
in throughput and cost per scan (£635–1300).
Implications for healthcare
The strongest evidence for the clinical effectiveness
of PET is in staging NSCLC, restaging HL,
staging/restaging colorectal cancer and detection of
SPN. Some of these may still require clinical audit
to augment the evidence base. Other management
decisions require further research to show the
impact of FDG-PET on patient management or
added value in the diagnostic pathway.
It is likely that new capital investment will be in
the newer PET/CT technology, for which there is
less evidence. However, as this technology appears
to be slightly more accurate than PET/CT, the PET
clinical effectiveness results presented here can be
extrapolated to cover PET/CT.
Recommendations for research
PET research could be undertaken on FDG-PET
or FDG-PET/CT, using a standard cancer work-up
process on typical patients who are seen within the
NHS in England. For treatment response and RT
planning, the need for larger studies using
consistent methods across the UK is highlighted as
a priority for all cancers.
For all studies, consideration should be given to
collaboration across sites nationally and
internationally, taking cognisance of the work of
the National Cancer Research Institute.
Facey K, Bradbury I, Laking G, Payne E. Overview
of the clinical effectiveness of positron emission
tomography imaging in selected cancers. Health
Technol Assess 2007;11(44).
Health Technology Assessment 2007; Vol. 11: No. 44 (Executive summary)
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