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BBACKGROUND:The aim of this paper was to analyse our own semi-quantitative method of assessing focal lesions localised in pre-operative diagnostic scintigraphy of primary hyperparathyroidism (PHPT) using 99m Tc-MIBI with washout and comparing these data with the result of the histopathological examination (HP). MATERIAL AND METHODS:A total of 40 (37 female, 3 male, average age 58.7 years) patients with a suspicion of PHPT were enrolled for prospective analysis. Dual phase planar and SPECT/CT examination with 99m Tc-MIBI were performed. The tumour to background ratios in the 10 th and 120 th minute were calculated (TBR10 and TBR120) on the basis of the planar acquisition.PTH, ionised calcium and phosphate levels were measured.Parathyroid surgery alone or combined with subtotal/total thyreoidectomy was conducted in 23 (57.5%) and 17 (42.5%) patients, respectively. A HP was performed in all patients. RESULTS:Average concentration of PTH in the whole group was 243.95 pg/ml. There was a statistically significant correlation between medians of PTH concentration and parathyroid histopathological results (p = 0.01). A total of 45 lesions of increased uptake were found in 32 (80.0%) and 34 (85%) patients in the early phase and the delayed phase, respectively.The post-operative material contained 20 (44.5%) parathyroid adenomas, 11 (24.5%) cases of hyperplasia, 2 (4.4%) cancers, 4 (8.9%) cases of normal parathyroid tissue, 2 (4.4%) lymph nodes and 6 (13.3%) cases of thyroid gland tissue.The medians of TBR10 and TBR120 for lesions examined in the HP were respectively: 3.64 and 2.59 for adenoma; 3.08 and 2.18 for hyperplasia; 7.7 and 5.5 for parathyroid cancer, 4.89 and 3.16 for normal tissue and 5.26 and 2.95 for lymph nodes or thyroid gland tissue.A high correlation coefficient of TBR10 to TBR120 in the parathyroid adenoma and parathyroid hyperplasia groups was observed with r = 0.867 and r = 0.964, respectively. The ρr correlation coefficient of TBR10 to TBR120 for normal parathyroid was 0.4.There was a statistically significant association between the HP and TBR10 medians (p = 0.047), but not between histopathology and TBR120 medians (p = 0.840

Staff at nuclear medicine departments receive doses of ionising radiation higher than the staff of radiotherapy and radiology departments, with the exception of interventional radiologists. Due to the updated lower occupational exposure limit for the lens of the eye, we measured eye exposure in workers of the Nuclear Medicine Department, Pomeranian Medical University in Szczecin, Poland. EYE-D™ dosimeters were used for 3 months by 10 employees working with sources of ionising radiation. Personal dosimeters also measured the exposure of the whole body and hands. The 3-month dose equivalents for the lens of the eye in the employees was 0.20-0.72 mSv. Staff at NMD PMU do not require regular routine eye lens dose monitoring. Eye lens doses were well within the new annual limit of 20 mSv. Doses to the whole body may be used as an indicator of the eye lens doses in the monitored department.

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Featured Application: The analyzed technique allows the estimation of parameters of small objects from SPECT volumes. Data analysis was based on Particle Swarm Optimization that reduces error between assumed model and measurements. Analysis by Synthesis was used for the estimation of parameters. Abstract: The paper introduces a fitting method for Single-Photon Emission Computed Tomography (SPECT) images of parathyroid glands using generalized Gaussian function for quantitative assessment of preoperative parathyroid SPECT/CT scintigraphy results in a large patient cohort. Parathyroid glands are very small for SPECT acquisition and the overlapping of 3D distributions was observed. The application of multivariate generalized Gaussian function mixture allows modeling, but results depend on the optimization algorithm. Particle Swarm Optimization (PSO) with global best, ring, and random neighborhood topologies were compared. The obtained results show benefits of random neighborhood topology that gives a smaller error for 3D position and the position estimation was improved by about 3% voxel size, but the most important is the reduction of processing time to a few minutes, compared to a few hours in relation to the random walk algorithm. Moreover, the frequency of obtaining low MSE values was more than two times higher for this topology. The presented method based on random neighborhood topology allows quantifying activity in a specific voxel in a short time and could be applied it in clinical practice.