Evaluation of the Radiation Dose of an Embryo/Fetus during Lymphoscintigraphy (Sentinel Lymph Node Mapping) in Pregnant Patients with Breast Cancer

Purpose: To develop a method for evaluation of the radiation dose of an embryo/fetus during lymphoscintigraphy (sentinel lymph node mapping) in pregnant patients with breast cancer.Material and methods: Two pregnant women (aged 43 and 30) with breast cancer stage IIA (T2N0M0), during the second trimester of pregnancy. We used a lymphotropic colloidal radiopharmaceutical labeled with 99mTc. To evaluate the radiation dose of an embryo, each patient had 6 individual dosimeters, which were placed around the abdomen using an elastic bandage at equal distances around the abdomen. Additionally, we placed the 7th dosimeter, it was placed near the injection site (under the mammary gland). After installing individual dosimeters, radiocolloid was injected into the affected mammary gland at four points (periareolar). The administered activity of radiopharmaceutical was 32.5 MBq, and 51.5 MBq. Lymphoscintigraphy was performed 1 hour after injection. First patient underwent sector resection of the left breast with SLN biopsy. The second patient underwent right mastectomy with SLN biopsy and breast reconstruction surgery using a tissue expander.Results: Based on the results of the study, the dose rate was calculated, on the basis of which the fetal radiation doses were calculated in both patients. Comparison of the mathematical data of both patients shows that, the calculated and experimental values of radiation exposure to the fetus during the radionuclide study of sentinel lymph nodes practically coincide. The obtained data shows that during pregnancy (280 days) the embryo/fetus will accumulate a natural radiation background dose of 1960 μSv, which is 2 times higher than the dose from the radionuclide study of sentinel lymph nodes. Thus these results verify the safety of SLN biopsy technology in pregnancy.Conclusion: 1. Radionuclide diagnostic studies of pregnant women determine radiation doses to the embryo/fetus that do not cause any radiation-induced effects in the prenatal period, and the probability of the occurrence of stochastic radiation-induced effects is several times lower than the incidence of endogenous cancers. 2. Radionuclide examination of sentinel lymph nodes appears to be safe for the fetus when conducted in pregnant women diagnosed with breast cancer. 3. In Russian Federation this method is used for the first time in pregnant women with diagnosed breast cancer. This technology has not been previously described in Russian literature.

Surface denudation and soil erosion over 300 ka at the Otago upland (New Zealand) using 10Be and 239+240Pu

<p>The Tor Exhumation Approach (TEA) traditionally uses large residual granitic landforms as indicators for surface lowering over time of their surrounding landscape. This study challenged the broad applicability of this approach by using large metamorphic residual landforms instead of the traditional plutonic rock formations. We applied in-situ cosmogenic nuclide techniques (<sup>10</sup>Be) along vertical landforms (schist-tors) on the Otago upland in southern New Zealand to investigate the capabilities of the TEA within another major rock type. The aim of the investigation was to decipher surface denudation models for the last ~100 ka. The experiment was coupled with fallout radionuclides (<sup>239+240</sup>Pu) in nearby soils to compare the Pleistocene / Holocene surface denudation rates with the Anthropocene (last ~60 years).</p><p>The surface ages of the eight investigated schist-tors was between ~20 ka and ~300 ka. This allowed the numerical modeling of continuous surface denudation rates with highest values near 0.16-0.20 [mm year<sup>-1</sup>] (about 140–180 [t km<sup>-2</sup>year<sup>-1</sup>]), and over a period that has not yet been achieved. The fallout radionuclide study resulted in two different mass redistribution rates. Average soil erosion along a ridge was ~400 to ~850 [t km<sup>-2</sup>year<sup>-1</sup>], whereas in an adjacent valley soil deposition rates reached ~130 to ~1,500 [t km<sup>-2</sup>year<sup>-1</sup>]. In conclusion, this study provides a new basis on how schist-tors emerge at two different landscape positions (ridges and valleys). In addition, differences between past surface denudation rates and modern ones could be revealed.</p>

Differential diagnosis of morphological forms of congenital hyperinsulinism using [18F]-DOPA PET/CT

Congenital hyperinsulinism (CHI) is caused by insulin hyperproduction by β-pancreatic cells. CHI is associated with high risk of complications of chronic hypoglycemia, and therefore timely diagnosis of the disease and immediate initiation of therapy is a top-priority task. The choice of treatment tactics largely depends on the morphological form of the disease. Morphological form cannot be established based on clinical and laboratory presentation of the disease, ultrasound, MRI, computed and positron emission tomography (PET) with [18F]-fluorodeoxyglucose. Calcium stimulation test and percutaneous transhepatic blood sampling from the portal vein were previously used for differential diagnosis, but the results provided by these invasive studies are imprecise. At present, preoperative differential diagnosis of diffuse and focal forms of CHI is based on the data of genetic testing and radionuclide diagnosis ([18F]-DOPA PET). The article presents the first results of the use of [18F]-DOPA PET in CHI patients in the Russian Federation. Radionuclide study was performed in 17 patients with pharmacoresistant CHI followed by comparative analysis of the results of 18F-FDG PET/CT and histological picture of intraoperative pancreatic tissue samples, which is known as the gold standard for the differential diagnosis of HI histological forms.

X-RAY MORPHOLOGICAL SEMIOTICS OF NON-TUBERCULOUS MYCOBACTERIAL PULMONARY DISEASE

Objective: to evaluate the X-ray radiological features of nontuberculous mycobacterial pulmonary disease (NTMPD) versus morphological findings.Material and methods. The investigation enrolled 37 patients, in whom the radiographic signs of dissemination were determined and various types of NTMPD were identified. The investigation was conducted on a Siemens Somatom Emotion 16 multislice computed tomography (MSCT) scanner using a high-resolution algorithm (Quick Time Virtual Reality). To clarify the activity of pathological changes in the thoracic organs, 16 (43.2%) patients underwent a radionuclide study with 99mTc-technetrile on a Nucline Spirit gamma camera in planar and single photon emission computed tomography modes.The diagnosis was verified by sputum smear microscopy and clinical laboratory and bronchologic examinations: bronchoalveolar lavage in 11 (29.7%) patients, various types of bronchial biopsies in 17 (46.0%), morphological examinations, and videoassisted thoracoscopic surgery for pulmonary resection in 9 (24.3%).Results. The dissemination foci in mycobacterial diseases were characterized by their location in the lung parenchyma with vascular and bronchial involvement and reactive changes in the pulmonary pleurae and intrathoracic lymph nodes (ITLN). In 92.7% of cases, the detected foci were predominantly centrilobular with endobronchial localization. Their contours were mixed with clear and fuzzy outlines in 98.7% of cases. In 70.3% of cases, the foci were asymmetrically localized mainly in the subpleural areas of the lung and 12.3% of cases were accompanied by reactive involvement of the visceral pleura.CT study revealed a tree-in-bud sign in 96.7% of cases, frosted glass in 10.2%, and mosaic perfusion in 13.2%. A more than 10-mm increase in ITLN was found in 11.7% of cases.In a number of cases, it was difficult to speak about the activity of the pathological process in the lung and ITLN, as shown by MSCT. In this case, a lung radionuclide study with 99mTc-technetrile was carried out in the planar mode. The degree of tracer accumulation, localization, and extent were analyzed in the planar mode.Conclusion. Thus, the CT typical signs of NTMPD are the asymmetric location of its foci with an endobronchial extension, peribronchovascular localization of foci; the presence of a CT tree-in-bud sign; and the slight involvement of the pulmonary pleurae in the process. 99mTs-technetril radionuclide study has established that the most active inflammatory process is located in the lung and the tracer accumulates in the pathologically altered lymph nodes.

Radionuclide study in gastroparesis: Is it still relevant?

The incidence of gastroparesis in Malaysia is not well documented. Gastroparesis may present with various combinations of debilitating sign and symptoms that decrease quality of life and increases morbidity. It is diagnosed based on clinical symptoms and exclusion of the obstruction. There should be a high index of suspicion in patients who present with symptoms to avoid missing the diagnosis. There are various approaches to study the gastric motility. Here’s a case of a young adult woman with type 1 diabetes mellitus suffering severe gastrointestinal symptoms. In this case, radionuclide scintigraphy is used as one of the investigation to confirm the diagnosis of gastroparesis. Radionuclide scintigraphy remains a hallmark in the diagnosis of gastroparesis after excluding mechanical obstruction.