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Background: The use of computed tomography (CT) for attenuation correction (AC) in whole‐body PET/CT can result in a significant contribution to radiation exposure. This can become a limiting factor for reducing considerably the overall radiation exposure of the patient when using the new long axial field of view (LAFOV) PET scanners. However, recent CT technology have introduced features such as the tin (Sn) filter, which can substantially reduce the CT radiation dose. Purpose: The purpose of this study was to investigate the ultra‐low dose CT for attenuation correction using the Sn filter together with other dose reduction options such as tube current (mAs) reduction. We explore the impact of dose reduction in the context of AC‐CT and how it affects PET image quality. Methods: The study evaluated a range of ultra‐low dose CT protocols using five physical phantoms that represented a broad collection of tissue electron densities. A long axial field of view (LAFOV) PET/CT scanner was used to scan all phantoms, applying various CT dose reduction parameters such as reducing tube current (mAs), increasing the pitch value, and applying the Sn filter. The effective dose resulting from the CT scans was determined using the CTDIVol reported by the scanner. Several voxel‐based and volumes of interest (VOI)‐based comparisons were performed to compare the ultra‐low dose CT images, the generated attenuation maps, and corresponding PET images against those images acquired with the standard low dose CT protocol. Finally, two patient datasets were acquired using one of the suggested ultra‐low dose CT settings. Results: By incorporating the Sn filter and adjusting mAs to the lowest available value, the radiation dose in CT images of PBU‐60 phantom was significantly reduced; resulting in an effective dose of nearly 2% compared to the routine low dose CT protocols currently in clinical use. The assessment of PET images using VOI and voxel‐based comparisons indicated relative differences (RD%) of under 6% for mean activity concentration (AC) in the torso phantom and patient dataset and under 8% for a source point in the CIRS phantom. The maximum RD% value of AC was 14% for the point source in the CIRS phantom. Increasing the tube current from 6 mAs to 30 mAs in patients with high BMI, or with arms down, can suppress the photon starvation artifact, whilst still preserving a dose reduction of 90%. Conclusions: Introducing a Sn filter in CT imaging lowers radiation dose by more than 90%. This reduction has minimal effect on PET image quantification at least for patients without Body Mass Index (BMI) higher than 30. Notably, this study results need validation using a larger clinical PET/CT dataset in the future, including patients with higher BMI. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine the adherence to consensus guidelines on preoperative imaging of patients with primary hyperparathyroidism (pHPT) in real local practice. Methods: This was a retrospective multicenter cohort study of 411 patients undergoing parathyroidectomy for pHPT from 2007 to 2017 in three referral centers. Results: In 286/411 patients (69%) the preoperative imaging workup adhered to guidelines (utilizing ultrasound and parathyroid scintigraphy). In patients in whom guidelines were followed 63% were discharged within one day versus 37% in whom guidelines were not followed (P <.0005). The use of a bimodality imaging workup, starting with ultrasound and parathyroid scintigraphy followed by imaging upscaling aiming for anatomical and functional concordance, was a predictor for the performance of a minimally invasive parathyroidectomy (OR 4.098, 95% CI 2.296‐7.315, P <.0005). Conclusion: The level of compliance to preoperative imaging guidelines is suboptimal in this population. Patients in whom adherence was achieved showed a shorter length of stay. More education of physicians is required regarding the appropriate preoperative imaging workup in pHPT. Level of evidence: 2b (individual cohort study). [ABSTRACT FROM AUTHOR]

Objective Thyroglobulin (Tg) is an excellent tumour marker, as detectable or increasing Tg levels are highly indicative of persistent or recurrent differentiated thyroid carcinoma ( DTC). The clinical value of a highly sensitive (hs)-Tg assay in patients with DTC has not yet been established. The aim of this study was to investigate the additional value of unstimulated hs-Tg measurements (Tg-on) compared to stimulated IRMA-Tg measurements (Tg-off) in the follow-up of patients with DTC. Design, patients, measurements We retrospectively studied patients treated for DTC between 2006 and 2013 and compared hs-Tg and IRMA-Tg measurements. The study group consisted of 99 DTC patients in remission; Tg-on was measured 3 months after remnant ablation and Tg-off 6 months after ablation. Results In the study group, 44 patients showed a hs-Tg-on <0·15 μg/l (functional sensitivity); of these, 43 had an IRMA-Tg-off measurement <1·0 μg/l, resulting in a negative predictive value of 97·7% and a positive predictive value of 56·4%. Conclusions The hs-Tg-on measurement is able to predict patients with an IRMA-Tg-off <1·0 μg/l, and therefore decreases the need for Tg stimulation after ablation. [ABSTRACT FROM AUTHOR]

Background There is debate if the lymphatic drainage pattern of oral maxillary cancer is to the retropharyngeal lymph nodes or to the cervical lymph nodes. Insight in drainage patterns is important for the indication for neck treatment. The purpose of this study was to identify the lymphatic drainage pattern of oral maxillary cancer via preoperative lymphoscintigraphy. Methods Eleven consecutive patients with oral maxillary cancer treated in our center between December 1, 2012, and April 22, 2016 were studied. Sentinel lymph nodes identified by preoperative lymphoscintigraphy after injection of 99mTc-nanocolloid and by intraoperative detection using a γ-probe, were surgically removed and histopathologically examined. Results In 10 patients, sentinel lymph nodes were detected and harvested at cervical levels I, II, or III in the neck. In 2 patients, a parapharyngeal sentinel lymph node was detected. One of the harvested sentinel lymph nodes (1/19) was tumor positive. Conclusion This study suggests the likelihood of 73% of exclusively cervical level I to III sentinel lymph nodes in oral maxillary cancer. © 2016 Wiley Periodicals, Inc. Head Neck 39: 486-491, 2017 [ABSTRACT FROM AUTHOR]

The article presents a case study of a 19-year-old woman diagnosed with a stage IV primary mediastinal large B-cell lymphoma with a bulky mass. She was administered with several drugs including vincristine, doxorubicin and cyclophosphamide along with a scan that was performed using F-fluorodeoxyglucose positron-emission tomography (F-FDG PET). The article discusses the potential failures in cancer diagnosis due to normal physiological F-FDG uptake in spinal cord.