Fortuitous discovery of non-fluorocholine-fixing papillary carcinoma of vesicular variant of the thyroid.

PURPOSE: Characterization of thyroid nodules is crucial to propose surgical intervention for histological verification. Cervical ultrasound potentially combined with fine needle aspiration is recommended, and fluorocholine positron emission tomography (FCH-PET), commonly used in prostatic cancers, has been evaluated in the diagnosis of thyroid cancers in recent publications. METHODS: We present two cases of patients with multinodular thyroid and primary hyperparathyroidism. The preoperative assessment consisted of an ultrasound, a MIBI scintigraphy and an FCH-PET in favor of a parathyroid adenoma. RESULTS: The imaging examinations pointed to a diagnosis of a parathyroid adenoma. In both cases, papillary thyroid carcinoma, missed by FCH-PET, was discovered incidentally at a distance from the parathyroid adenoma during the surgical procedure. CONCLUSIONS: These are the first descriptions of thyroid papillary carcinoma without preoperative FCH-PET identification. These clinical cases are contrary to recent publications showing a benefit of this examination in the diagnosis of thyroid cancers.

Modeling tumor size dynamics based on real-world electronic health records and image data in advanced melanoma patients receiving immunotherapy.

The development of immune checkpoint inhibitors (ICIs) has revolutionized cancer therapy but only a fraction of patients benefits from this therapy. Model-informed drug development can be used to assess prognostic and predictive clinical factors or biomarkers associated with treatment response. Most pharmacometric models have thus far been developed using data from randomized clinical trials, and further studies are needed to translate their findings into the real-world setting. We developed a tumor growth inhibition model based on real-world clinical and imaging data in a population of 91 advanced melanoma patients receiving ICIs (i.e., ipilimumab, nivolumab, and pembrolizumab). Drug effect was modeled as an ON/OFF treatment effect, with a tumor killing rate constant identical for the three drugs. Significant and clinically relevant covariate effects of albumin, neutrophil to lymphocyte ratio, and Eastern Cooperative Oncology Group (ECOG) performance status were identified on the baseline tumor volume parameter, as well as NRAS mutation on tumor growth rate constant using standard pharmacometric approaches. In a population subgroup (n = 38), we had the opportunity to conduct an exploratory analysis of image-based covariates (i.e., radiomics features), by combining machine learning and conventional pharmacometric covariate selection approaches. Overall, we demonstrated an innovative pipeline for longitudinal analyses of clinical and imaging RWD with a high-dimensional covariate selection method that enabled the identification of factors associated with tumor dynamics. This study also provides a proof of concept for using radiomics features as model covariates.

Diagnostic Performance of Cervical Ultrasound, 99mTc-Sestamibi Scintigraphy, and Contrast-Enhanced 18F-Fluorocholine PET in Primary Hyperparathyroidism.

Preoperative localization of pathologic parathyroids is crucial for minimally invasive treatment of primary hyperparathyroidism (PHPT). This study compared contrast-enhanced 18F-fluorocholine PET/CT, cervical ultrasonography (CU), and conventional scintigraphic imaging modalities (MIBI scintigraphy, consisting of 99mTc-sestamibi/123I-sodium iodide SPECT/CT, 99mTc-sestamibi/123I-sodium iodide planar subtraction imaging, and 99mTc-sestamibi planar dual-phase imaging), combined and individually, for preoperative localization of hyperfunctional parathyroids in PHPT. The gold standard was histologic examination. Methods: Data from consecutive patients with clinically suspected PHPT were retrospectively collected. All 3 imaging modalities were systematically performed. The ability of 18F-fluorocholine PET/CT, CU, and MIBI scintigraphy to identify a hyperfunctional parathyroid and specify the side or identify an ectopic location was noted. Patients underwent surgical exploration if at least 1 examination was positive. The findings of CU + MIBI scintigraphy combined were considered positive if CU and MIBI scintigraphy separately showed a hyperfunctional parathyroid gland on the same side or in the same ectopic location; any findings other than these were considered negative. The composite judgment criterion for pathologic parathyroid was a combination of histologic analysis and normalization of parathyroid hormone and calcium levels. Results: In total, 149 pathologic parathyroids were found in 143 of the 144 included patients. 18F-fluorocholine PET/CT diagnosed 148 of 149 pathologic parathyroids. Only 4 false-positives and 1 false-negative were found. The 18F-fluorocholine PET/CT sensitivity of 99.3% was superior to that of CU, at 75.2% (P < 0.0001); MIBI scintigraphy, at 65.1% (P < 0.0001); and CU + MIBI scintigraphy, at 89.9%, (P = 0.0009). Five of the 5 ectopic locations were diagnosed by 18F-fluorocholine PET/CT, 2 of the 5 by MIBI scintigraphy, and none by CU. Accuracy was better for 18F-fluorocholine PET/CT, at 98%, than for CU, at 84% (P < 0.0001); MIBI scintigraphy, at 81% (P < 0.0001); or CU + MIBI scintigraphy, at 91% (P < 0.0001). Among the 72 (50%) patients who had a negative CU + MIBI scintigraphy result, 18F-fluorocholine PET/CT correctly identified hyperfunctional thyroids in 70 (97.2%). Average uptake in the 18F-fluorocholine PET/CT hyperfunctional parathyroid was higher than that in the adjacent thyroid (SUVmax adjusted for lean body mass, 6.45 vs. 2.15) (P < 0.0001). Conclusion: The accuracy of 18F-fluorocholine PET/CT is higher than that of CU and MIBI scintigraphy for localization of hyperfunctional parathyroids, justifying the systematic use of 18F-fluorocholine PET/CT as the first-line method for PHPT diagnosis.

Brain death determination in Australia and New Zealand: a survey of intensive care units.

BACKGROUND: The Australian and New Zealand Intensive Care Society (ANZICS) guidelines for the determination of brain death involve clinical testing and/or the use of brain blood flow analysis techniques. Recently, there has been professional and lay discussion regarding the role of brain blood flow analysis in the determination of brain death. OBJECTIVE: To determine the current practices in Australian and New Zealand intensive care units for the determination of brain death. METHODS: All adult ICUs in Australia and New Zealand accredited for training in intensive care by the College of Intensive Care Medicine of Australia and New Zealand were surveyed to determine the unit size, whether certification of brain death occurs in that unit, and the method routinely used to determine brain death if there were no contraindications to clinical testing. RESULTS: There were 47 responses (53% response rate). Of the surveyed units, 89% of units used two sets of clinical tests for brain death determination; 9% used one set of clinical testing and one imaging technique; and 2% of units used one imaging technique only. When an imaging technique was used, four units used radionuclide imaging, one unit used magnetic resonance imaging and one unit used computed tomography angiography. CONCLUSIONS: Two sets of clinical testing is the most common method for determining brain death in Australian and New Zealand ICUs. A minority of units used some form of brain blood flow imaging. Based on these findings, all brain death certification is in accordance with ANZICS guidelines.