Positron emission tomography and positron emission tomography-CT evaluation for recurrent papillary thyroid carcinoma: meta-analysis and literature review.

BACKGROUND Sensitivity and specificity data regarding positron emission tomography (PET) and PET/CT for surveillance of well-differentiated thyroid cancer does not evaluate subtypes separately. Papillary and follicular thyroid carcinoma may have different characteristics on PET/CT imaging and so should be investigated individually. METHODS This is a systematic meta-analysis of studies using PET for surveillance in patients with papillary thyroid carcinoma. RESULTS Using different statistical models, combined sensitivity of PET and PET/CT for papillary thyroid carcinoma was 77% by the fixed effect model and 82% by the random-effects model, specificity was calculated as 85% and 84%, respectively. Meta-regression was performed to evaluate whether I-131 negativity affected PET positivity; no correlation between I-131 negativity and PET sensitivity or specificity was found. CONCLUSION PET and PET/CT are useful modalities in surveillance of papillary thyroid carcinoma. To our knowledge, this is the first study to examine papillary thyroid carcinoma independently of other subtypes of well-differentiated thyroid carcinoma.