Thyroid cancer is the most common endocrine neoplasm and is the 12th most common cancer among all cancer types (1). The median 5-year survival rate for thyroid cancer was 98% between 2009 and 2015; however, prognosis is poor in more aggressive subtypes. For example, anaplastic thyroid cancer (ATC) accounts for less than 1% of all thyroid cancers, but the median survival is three to seven months and the 1-year survival rate is 10-20% (1,2). The incidence of thyroid cancer is almost double now than it was in 2000, accounting for 2.1% of cancer diagnoses (3,4). Between 1974 and 2013, the mean age of thyroid cancer diagnosis was 48±16. Women are more commonly affected than men, accounting for 75% of the diagnoses (5). There is increased incidence of thyroid cancer in the geriatric population who also have a worse prognosis from thyroid cancer due to increased treatment related morbidity and mortality (3). Due to the high recurrence rate in thyroid cancer (20%), the ability to distinguish recurrence from treatment related changes are key to improving survival (6). Thyroid cancer subtypesThere are four major subtypes of thyroid cancer: papillary (PTC), follicular (FTC), anaplastic (ATC), and medullary thyroid cancer (MTC) (1). Less common subtypes include: Hurthle cell carcinoma (HTC) and poorly differentiated thyroid cancer (PDTC). PTC, FTC, and HTC are well differentiated subtypes; accounting for approximately 95% of thyroid cancers (1). These subtypes generally have a better prognosis than PDTC and ATC subtypes. PTC Review Article on Role of Precision Imaging in Thoracic Disease

Theranostics is a re-emerging field of medicine that aims to create targeted agents that can be used for diagnostic and/or therapeutic indications. In the past, theranostics has been used to treat neoplasms, such as thyroid cancer and neuroblastomas. More recently, theranostics has seen a resurgence with advent of new therapeutic antibodies and small molecules which can be transformed into Theranostic agents through radioconjugating with a radioactive isotope. Positron emitting radioisotopes can be used for diagnostic purposes while alpha-and beta-emitting radioisotopes can be used for therapy. The technique of radiolabeling an existing therapeutic agent (small molecule or antibody) leverages the existing qualities of that drug, and potentiates therapeutic effect by conjugating it with a cytotoxic-energy bearing radioisotope (e.g., 131-iodine, 177-lutetium). Theranostics have been used for a few decades now, starting with 131-iodine for therapy of autoimmune thyroiditis (Graves' disease, Hashimoto's thyroiditis) as well as for thyroid cancer. Additionally, 131-iodine-meta-iodobenzylguanidine (131-I-MIBG) initially had been used for gastroenteropancreatic neuroendocrine (carcinoid) tumors. However, recently clinical trials have start enrolling patients to evaluate efficacy of 131-I-MIBG in patients with small cell carcinoma of the lung. In the era of precision medicine and personalized targeted therapeutics, Theranostics can play a key pivotal in improving diagnostic and therapeutic specificity by increasing potency of these targeted small molecules and antibodies with radioisotopes. In this review, we will review various clinically relevant Theranostics agent and their utility in thoracic disorders, notably within oncology.