Defining inappropriate thyroid biopsy?-Proposed definition based on clinical evidence and stakeholder engagement.

PURPOSE: Identify factors that can be used to assess the appropriateness of a thyroid biopsy and propose a pathway to define inappropriate thyroid biopsies in practice. METHODS: We identified factors utilized in clinical guidelines and existing literature to determine the clinical indications for a thyroid biopsy. Subsequently, we assembled a multidisciplinary panel of experts, including patients, clinicians, researchers, and quality experts, to integrate these factors and develop a pathway for assessing the appropriateness of thyroid biopsies. RESULTS: Through literature review and stakeholder engagement, we identified multiple factors to determine if a thyroid biopsy is necessary: ultrasound risk assessment, presence of compressive symptoms and/or clinical suspicion of high-risk thyroid cancer, life expectancy, comorbidity burden, surgical risk, personal risk factors for thyroid cancer, thyroid function levels, local resources and medical expertise and patient values and preferences. We proposed a multiple-tier classification for the appropriateness of thyroid biopsy that begins with ultrasound findings (e.g., size, thyroid cancer risk) and encompasses the evaluation of additional patient-specific factors. CONCLUSION: Assessment of the appropriateness of a thyroid biopsy is possible. Although, thyroid nodule ultrasound risk assessment is a pivotal factor for this assessment, additional factors should be considered (e.g., life expectancy, personal risk factors for thyroid cancer, patient preferences). Yet, additional efforts are needed to operationalize the objective implementation of these factors in clinical practice.

Synthetic Access to All Four Stereoisomers of Oxetin.

A short synthesis of all four stereoisomers of 3-amino-2-oxetanecarboxylic acid (oxetin) is described. The oxetane core is built using a Paternò-Büchi photochemical [2 + 2] cycloaddition; from the key intermediates, complementary resolution protocols provide access to enantiomerically pure oxetin and epi-oxetin on gram-scale.