2017 Section 7 Green Book

proliferating neoplastic cells consume glucose at a higher

rate than normal cells do, the glucose analogue 18-F-

fluorodeoxyglucose (18-FDG) accumulates at higher rates

within malignant cells. However, nonspecific increases in

the uptake of FDG within cells can also occur in normal

salivary glands and lymphoid tissues and in the setting of

infection and inflammation, such as that which occurs

after radiotherapy.

The aim of our systematic review and meta-analysis was

to evaluate the diagnostic accuracy of PET and PET/CT for

detecting residual and/or recurrent local and regional disease

and distant metastases in patients with HNSCCs following

radiotherapy or chemoradiotherapy. Hereafter, PET and

PET/CT will be collectively referred to as PET, with dis-

tinctions made where necessary.

Methods

Search Methodology

We searched EMBASE, PREMEDLINE, MEDLINE, and

GoogleScholar for studies evaluating the diagnostic perfor-

mance of FDG-PET in head and neck cancers. Additional

relevant studies were identified by reviewing the reference

list of articles retrieved and searching the Cochrane

Database for Systematic Reviews. We used a search strategy

based on a variety of keywords and Medical Subject

Heading (MeSH) terms, with the search algorithm modified

as necessary for each database Search terms included

positron emission tomography, head and neck neoplasm,

squamous cell carcinoma, local neoplasm recurrence,

residual neoplasm, squamous cell carcinoma, local neoplasm

recurrence, sensitivity and specificity

(see Supplementary

Appendix 1 and 2 at

www.otojournal.org/supplemental

There were no language restrictions for our search, and

we included all prospective studies published until

February 28, 2015.

Study Selection and Eligibility Criteria

Two reviewers were involved in the selection of studies,

data collection, and quality assessment process; any dis-

agreements were resolved by consensus or by discussion

with a third reviewer.

Citations were initially screened to determine whether

they pertained to the use of imaging in head and neck can-

cers. The abstracts were then assessed for eligibility for

inclusion based on the following criteria:

FDG-PET or FDG-PET/CT for posttreatment response

assessment or surveillance for residual or recurrent

head and neck cancer after treatment with radiotherapy

or chemoradiotherapy

Histopathological analysis and/or close clinical and

imaging follow-up was used as the reference

standard

Data on the number of true-positive, true-negative,

false-positive, and false-negative results were avail-

able or could be extracted based on the sensitivity,

specificity, positive predictive value (PPV), and

negative predictive value (NPV) provided

Minimum of 10 patients

The full texts of these potentially eligible articles were

retrieved and evaluated to ensure that all inclusion criteria

were satisfied. Review articles, case reports, commentaries,

conference proceedings, and letters to the editor were

excluded. Retrospective studies were also excluded as these

may potentially overestimate the diagnostic accuracy. Only

patients with HNSCCs were included in this review; in stud-

ies in which the population had a mixture of histology, an

attempt was made to extract just the data on patients with

SCCs. Studies that did not specify SCCs or where it was not

possible to separate out the data on SCCs from other none-

pithelial tumors were excluded. Studies were also excluded

if part of the study population received surgery alone as the

treatment, if the primary treatment modality was not

reported, or if dual head coincidence gamma cameras were

used to capture the images.

Data Collection Process and Data Items

Data from each study were extracted onto a standardized

data extraction form. One reviewer collected the data, and a

second reviewer checked the extracted data. We recorded

the author names; journal; year of publication; sample size;

initial treatment modality; description of study population

including age, gender, site, and stage of disease; time to ini-

tial PET imaging; definition of positive PET scan (visual,

semiquantitative); location of recurrence (local, nodal, dis-

tant, all sites considered together); reference standard; and

duration of follow-up. The number of true-positive, true-

negative, false-positive, and false-negative results was

recorded or extracted onto a 2

2 table based on the sensi-

tivity, specificity, PPV, NPV, and sample size data pro-

vided. Based on the data in these tables, the sensitivity,

specificity, PPV, NPV, and overall accuracy were calculated

for each study.

Quality Assessment of Studies

The quality of each article was assessed using the Quality

Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

This 14-item assessment tool was developed by the Centre

for Reviews and Dissemination at the University of New

York and the Academic Medical Centre at the University of

Amsterdam to allow for the consistent and reliable assess-

ment of the quality of diagnostic accuracy studies included a

systematic review.

Specifically, the tool assists in assessing

the risk of bias, sources of variation, and reporting quality of

diagnostic accuracy studies. We weighed each of these items

equally and attributed a summary score to each study based

on the responses to each question, with 1 for ‘‘yes,’’ 0 for

‘‘no,’’ and 0.5 for ‘‘unclear.’’

Statistical Analysis

The weighted mean pooled sensitivity, specificity, PPV,

NPV, diagnostic odds ratio (DOR), and their 95% confidence

Otolaryngology–Head and Neck Surgery 154(3)