The diagnostic value of dual-phase SPECT/CT scintigraphy based on transport kinetics of 99mTc-sestamibi confirmed with histopathological findings in patients with secondary hyperparathyroidism - practical consideration.

BACKGROUND: Dual phase 99mTc-sestamibi SPECT/CT preoperative parathyroid scintigraphy (PPS) is seldom discussed in terms of the transport kinetics of the tracer. OBJECTIVES: To assess the relationship between the characteristic type of tracer transport in particular PPS and histopathological findings in patients with secondary hyperparathyroidism (sHPT). MATERIAL AND METHODS: The study comprised 27 patients (13 females and 14 males) with sHPT. Based on tracer accumulation in early phase (EP) and delayed phase (DP), the following types of accumulation for PPS(+) lesions were identified: EP(-)/ DP(+) (type I), EP(+)/DP(+) (type II), EP(+)/DP(-) (type III). EP(-)/DP(-) (type IV) lesions constituted PPS(-) group invisible in SPECT/CT. Overall, 69 lesions 59 PPS(+) and 10 PPS(-) were evaluated histopathologically. RESULTS: Among SPECT/CT PPS(+), types I, II and III occurred in 9 (15%), 49 (83%), and 1 (2%) lesions, respectively. The frequency of histopathological diagnosis of normal and abnormal (APG - adenoma or hyperplasia) parathyroid gland, as well as non-parathyroid (thyroid, lymph nodes, or fat) lesions differed significantly between type I, II, and III lesions (p = 0.036). APG histopathological diagnosis was significantly more frequent in lesions with type II uptake than in lesions with type I uptake (76% vs. 33%, p = 0.0197). Type II lesions had significantly higher odds for histopathological diagnosis of APG or NPG than type IV, PPS(-) lesions [odds ratio = 13.1 (95% CI: 2.75 to 63.27)]. CONCLUSIONS: For SHP patients evaluated with SPECT/CT PPS accumulation type I is a weak premise for surgeon to find parathyroid pathology. Only persistent 99mTc-sestamibi accumulation in both phases - equivocal with accumulation type II - effectively differentiates parathyroid and non-parathyroid lesions as well as indicates with high probability the presence of adenoma or hyperplasia. Type III consistent with washout pattern is rare in sHPT.

SHOULD PERSONNEL OF NUCLEAR MEDICINE DEPARTMENTS USE PERSONAL DOSIMETERS FOR EYE LENS DOSE MONITORING?

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.

Semi-quantitative method for the assessment of focal lesions in parathyroid scintigraphy with relation to histopathology: a prospective study.

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 99mTc-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 99mTc-MIBI were performed. The tumour to background ratios in the 10th and 120th 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). CONCLUSIONS: The washout technique in pre-operative 99mTc-MIBI scintigraphy is effective in detecting lesions of the parathyroid (cancer, adenoma, hyperplasia, normal tissue of the parathyroid). Parathyroid cancers in semi-quantitative analysis were characterised by a slightly higher TBR. However, it is impossible to differentiate lesions based on this data. Histopathology results are significantly associated with TBR and PTH.

[The reference of normal values of the sacroiliac joint index in bone scintigraphy].

Introduction: Scintigraphy of sacroiliac joints as functional imaging provides unique information on the existing disease process. By using radiopharmaceuticals that allow imaging of the metabolic activity within the joint, it is possible to assess the stage of the disease, even when there are no lesions in radiological images. Quantitative analysis of scintigrams of sacroiliac joints is performed by comparing the uptake in both of them in relation to the uptake in the sacral bone area. The values of sacroiliac (SI/S) indices are influenced by the age of the patient, sex, state of health, and a range of individual biological features. Therefore, reference values of SI/S ratios are very important for medical specialists who describe and diagnose locomotor system diseases. The aim of this paper is to develop a reference range of sacroiliac ratios. The innovativeness of this paper involves examining sacroiliac ratios for various age groups, in children and adult patients, taking their sex into consideration. Materials and methods: The study comprised a group of 335 people with proper bone scintigraphy. These people were divided into children and patients aged ≥21. Children were divided into 4 age groups (1­5; 6­10; 11­15; 16­20) and adults into 6 age groups (21­30; 31­40; 41­50; 51­60; 61­70; ≥71). Sacroiliac ratios were calculated using the method of three rectangular region of interests located on the left and right sacroiliac joint and on the sacral bone. The sacroiliac ratio was calculated for both joints by dividing the average number of counts within a selected sacroiliac joint by the average number of counts within the sacral bone. Results: SI/S borderline reference values covered the range of 1.18÷2.28 that was obtained for children aged ≤5 and for the group of 11­15-year-olds. Considerable discrepancies in the values of the coefficient for women and men were seen among 31­50-year-olds. Conclusions: Borderline reference results for the entire control group cover the range of 1.18 ±2.28. The lower reference value applies to ≤5-year-olds, whereas the higher value applies to the group of 11­15-year-olds. The standard deviation value obtained was highest in paediatric patients. The results indicate the occurrence of significant individual differences between patients in this age group.