Background: Publication of the 2015 American Thyroid Association (ATA) management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer was met with disagreement by the extended nuclear medicine community with regard to some of the recommendations related to the diagnostic and therapeutic use of radioiodine (131 I). Because of these concerns, the European Association of Nuclear Medicine and the Society of Nuclear Medicine and Molecular Imaging declined to endorse the ATA guidelines. As a result of these differences in opinion, patients and clinicians risk receiving conflicting advice with regard to several key thyroid cancer management issues. Summary: To address some of the differences in opinion and controversies associated with the therapeutic uses of 131 I in differentiated thyroid cancer constructively, the ATA, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association each sent senior leadership and subject-matter experts to a two-day interactive meeting. The goals of this first meeting were to (i) formalize the dialogue and activities between the four societies; (ii) discuss indications for 131 I adjuvant treatment; (iii) define the optimal prescribed activity of 131 I for adjuvant treatment; and (iv) clarify the definition and classification of 131 I-refractory thyroid cancer. Conclusion: By fostering an open, productive, and evidence-based discussion, the Martinique meeting restored trust, confidence, and a sense of collegiality between individuals and organizations that are committed to optimal thyroid disease management. The result of this first meeting is a set of nine principles (The Martinique

We were able to define 26 consensus expert recommendations and a resulting algorithm for the care of TgAb-positive DTC patients.

Key Points• 18FDG PET/CT is a very important staging tool for patients with PMBCL. • Metabolic activity defined by TLG on the baseline PET scan is a powerful predictor of PMBCL outcome.The International Extranodal Lymphoma Study Group (IELSG) 26 study was designed to evaluate the role of 18 F-fluorodeoxyglucose (18FDG) positron emission tomography/ computed tomography (PET/CT) in the management of primary mediastinal (thymic) large B-cell lymphoma (PMBCL). We examined the prognostic impact of functional PET parameters at diagnosis. Metabolic activity defined by the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) was measured on baseline 18FDG PET/CT following a standard protocol in a prospectively enrolled cohort of 103 PMBCL patients. All received combination chemoimmunotherapy with doxorubicin-and rituximab-based regimens; 93 had consolidation radiotherapy. Cutoff values were determined using the receiver-operating characteristic curve. At a median follow-up of 36 months, progression-free survival (PFS) and overall survival (OS) were 87% and 94%, respectively. In univariate analysis, elevated MTV and TLG were significantly associated with worse PFS and OS. Only TLG retained statistical significance for both OS (P 5 .001) and PFS (P < .001) in multivariate analysis. At 5 years, OS was 100% for patients with low TLG vs 80% for those with high TLG (P 5 .0001), whereas PFS was 99% vs 64%, respectively (P < .0001). TLG on baseline PET appeared to be a powerful predictor of PMBCL outcomes and warrants further validation as a biomarker. The IELSG 26 study was registered at www.clinicaltrials.gov as #NCT00944567. (Blood. 2015;126(8):950-956)