Page 15 - Delaware Medical Journal - December 2016
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SCIENTIFIC ARTICLE
Introduction
tested by molecular testing include 1 (CBL Path), allows for high-throughput sequencing analysis of large regions of
the human genome.2 The ThyroSeq v2.1
molecular markers has been reported to provide both high sensitivity and high 92.1 percent, positive predictive value 2. Similarly, its predecessor ThyroSeq
v2.0 was reported to provide a highly
preoperative ThyroSeq v2.0 performed with 90 percent sensitivity, 93 percent 3
based on its reportedly high PPV and a thyroid nodule.2,3
of completion thyroidectomies among practices that recommends total thyroidectomy for differentiated thyroid cancer. In this setting the surgeon can perform a therapeutic total thyroidectomy
Positive and Negative Predictive Value
FIGURE 1
Bayes theorum in the calculation of positive and negative predictive value.
the number of unnecessary diagnostic surgeries by diverting nodules with negative test results to clinical observation diagnosis in about 25 percent of thyroid nodules.4 thyroid surgeries for indeterminate thyroid nodules performed solely for diagnostic purposes yield benign surgical pathology from the index nodule and in retrospect many of these surgeries were unnecessary.4
Bayes theorem (Figure 1) in the but also disease prevalence, or pre-test risk of malignancy. Disease prevalence rates are often completely unknown, not well characterized, and are subject to change. Clinicians have been cautioned
to consider how the molecular testing will perform in their unique patient populations and to know the individual practice and/or institutional prevalence of cancer for indeterminate thyroid nodules.
A personalized medicine approach includes considering not only prevalence of disease in the population but also
risk of disease in the unique patient,
and includes their history, exam,
and ultrasound. Individual clinical factors such as the nodule ultrasound characteristics help re-characterize the in the majority of Bethesda III and IV thyroid nodules and are associated with a malignancy risk of 20 percent or less7 are associated with a risk of malignancy of 70 percent or more7 and an expected
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