NUCLEAR MEDICINE REVIEW最新文献

[99mTc]MIBI thyroid scintigraphy is a useful tool to differentiate benign from malignant thyroid nodules. This report aims to show the diagnostic performance of [99mTc]MIBI scintigraphy used in an 83-year-old woman who had a thyroidectomy about 7 years ago. She had a mass of thyroid which was very large, non-homogenous and painless. [99mTc]MIBI scintigraphy could be a pre-surgical method to investigate the follicular nodules and predicting the malignant form of thyroid nodules. Also, it will provide tissue information for [99mTc]MIBI images in thyroid lesions.

Background: To evaluate the diagnostic performance of [¹⁸F]fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]FDG-PET/CT) scan in detecting local recurrences in patients with surgically treated oral tongue squamous cell cancer (OTSCC).

Material and methods: Eighty-seven patients who had undergone surgery for OTSCC were monitored clinically and [¹⁸F]FDGPET/CT and magnetic resonance (MR). PET uptakes were classified as functional (Type A), suspicious (Type B), or highly suggestive of local recurrence (Type C). A multidisciplinary team (MDT) evaluated case-by-case the surveillance strategy based on PET uptake.

Results: Fifty-nine patients presented FDG-PET uptake during follow-up: this report was significantly more frequent in patients who received flap reconstruction than in those without (73% vs 50%; p = 0.05). In 13 patients with Type A (n = 1), Type B (n = 9), and Type C (n = 3) uptakes an additional MR was considered preferable and discovered recurrence in 12.PET-CT had 9 true positives, 17 false positives, 71 true negatives, and no false-negative, resulting in sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of 100%, 80.7%, 34.6%, and 100%.

Conclusions: The present results demonstrated a change in diagnostic strategy, as decided by the MDT, in about one-fifth of patients. The results should prompt in designing a rational surveillance schedule in surgically treated OTSCC.

A 33-year-old female with a history of total thyroidectomy for papillary thyroid carcinoma was referred to the nuclear medicine department for ablative radioiodine therapy. Post ablation scan showed an area of intense iodine uptake on the left side of the pelvic region, corresponding to the large well-defined heterogeneous mass in the left ovary in the SPECT/CT images. The radiologic features of this lesion were compatible with a dermoid cyst, previously unrecognized. Eventually, the lesion was laparoscopically removed, and a typical dermoid cyst was confirmed through histopathologic assessment.

A 69 y/o woman with a history of primary diffuse large B cell lymphoma in the right thigh muscle was referred for recurrence evaluation with 18F-FDG PET/CT. After routine courses of chemoradiation, MRI was done in order to evaluate treatment response with inconclusive findings. 18FDG PET/CT revealed abnormal uptake in the primary site of the disease as well as secondary involvement of stomach, pancreas, pelvic lymph nodes, and both tibiae. Our case showed the importance of 18F-FDG PET/CT in the detection of unusual soft tissue extension of lymphoma.

Background: In the follow-up of patients with inflammatory bowel disease (IBD), Tc-99m-HMPAO labelled leukocytes scintigraphy (leukocyte scan; LS) has long been established as a valuable diagnostic tool. The aim of this study was to estimate the relationship between scintigraphic results, inflammatory markers (IM) (including white blood cells (WBCs) and C-reactive protein (CRP)), clinical parameters and clinical indices of the disease activity (CI), in order to determine clinical settings in which LS is indicated.

Materials and methods: A total of 147 patients who underwent LS, (79 males, 68 females, median age 36), were examined from April 2010 until December 2017 at the University Hospital Centre Zagreb, Croatia. Among these, 126 (86%) had Crohn's disease (CD) and 21 (14%) had ulcerative colitis (UC). Either increased IM (either WBCs ≥10x109/L and/or CRP ≥7.4 mg/L) and/or CI, Crohn's disease activity index (CDAI) score ≥220 points, Harvey-Bradshaw index (HBI) score ≥8 points, and severe colitis defined according to Truelove and Witts' criteria (TWC) for UC, respectively, were considered consistent with active disease.

Results: Eighty-two patients (56%) had negative scans, while in 65 (44%) the scans were positive. Positive correlations were found between LS and all of the 3 parameters, WBCs, CRP and CI. When combined, the 3 parameters demonstrated even stronger positive correlation with the LS results with the correlation coefficient 0.76 (p<0.0001, 95% CI [0.68-0.82]). Using endoscopy and histological study findings of the obtained specimens as a composite reference standard, the overall sensitivity, specificity, positive predictive value and negative predictive value of IM and CI for LS were determined, being 91%, 85%, 83%, and 92%, respectively. IM and CI were both negative in 76 (52%) out of the total subjects. Of these, 70 had negative LS as well.

Conclusion: In the presence of normal IM with CI pointing to no active or mildly active disease, LS is not necessarily indicated.

Background: Every exposure of human to ionizing radiation increases the likelihood of deterministic sequelae. At the same time, it is associated with the risk of stochastic effects. Consequently, this can lead to cancer, mainly of the hematopoietic system. Organs or tissues show a different affinity for gamma radiation. There are many technical and organizational measures which minimize the impact of this radiation on people and especially on the staff of the nuclear medicine laboratory.

Materials and methods: The study was based on 208 referrals to the scintigraphic laboratory, which were executed between 26.09.2018 and 13.11.2018 in the Department of Nuclear Medicine of Military Medical Academy Memorial Teaching Hospital of the Medical University of Lodz - Central Veterans` Hospital. Referrals concerned scintigraphic tests of bones, salivary glands, parathyroid glands, myocardial perfusion, somatostatin receptor analogues, renoscintigraphic and lymphoscintigraphic tests. In case of each referral, radiation power was measured at a distance of approx. 10 cm with the use of a calibrated Geiger-Muller detector. Measurements were performed immediately after the end of the last examination each day. Daily measurement of the background radiation dose was also a standard procedure. For calculations, this value was averaged to 0.18µSv/h. Based on the above measurements, a statistical analysis of all data was performed. Obtained data was also analysed after it was ascribed to the person complexing radiopharmaceuticals on a given day. The annual dose for a radiopharmacist is 0.12 mSv, for a technician 0.35 mSv and for a doctor 0.45 mSv.

Results: The average radiation dose received every working day by the staff was 11.49 µSv/h. After considering the average distance from the potential source of exposure (50 cm), this power decreased to 0.46µSv/h. In order to calculate the quarterly and annual radiation dose, it was assumed that the employee worked 250 days a year.

Conclusions: Medical records may pose an additional personnel exposure to ionizing radiation. Physicians are the most vulnerable group of employees. The way of radiopharmacists work contributes to the contamination of medical records.

We reported a 15-year-old girl with a history of mild left vesicoureteral reflux who underwent direct radionuclide cystography in our department. Bladder catheterization was mistakenly placed in the vagina. The filling phase showed vagina and uterine cavity which was similar to vesicoureteral reflux. The procedure was repeated with correct catheterization of the bladder and no vesicoureteral reflux was noted.

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.