SPECT-CT localization of axillary sentinel lymph nodes for radiotherapy of early breast cancer

PurposeTo evaluate the opportunities of single photon emission tomography/computerized tomography (SPECT-CT) for localization of axillary sentinel lymph nodes (ASLNs) and subsequent radiotherapy planning in women with early breast cancer.Material and methodsIndividual topography of ASLN was determined in 151 women with clinical T1-2N0M0 breast cancer. SPECT-CT visualization of ASLNs was initiated 120min after intra-peritumoral injection of 99mTc-radiocolloids. Doses absorbed by virtual ASLNs after the whole breast irradiation with standard and extended tangential fields were calculated on a treatment planning station.ResultsSPECT-CT demonstrated a large variability of ASLN localization. They were detected in the central subgroup in 94 (61%) patients, in pectoral – in 77 (51%), and in interpectoral – in 4 (3%) patients. Sentinel lymph nodes “lying on the chest” were revealed in 35 (23%) cases.We found that with standard tangential fields coverage of ASLNs was obtained only in 20% of evaluated women. Extended tangential fields can effectively irradiate ASLNs localized in all axillary sub-regions with the exception of ASLNs “lying on the chest”.ConclusionSPECT-CT mapping of ASLNs in women with cT1-2N0M0 breast cancer reveals their variable localization. This information can be important for planning of radiation treatment in women that underwent breast conserving surgery without an axillary surgery

Lymph flow guided irradiation of regional lymph nodes in patients with cervical cancer: Preliminary analysis of scintigraphic data

PurposeTo evaluate patterns of lymph flow from primary lesions in patients with cervical cancer and to determine how useful for radiotherapy planning this information can be.Materials and methodsSPECT–CT visualization of sentinel (SLN) lymph nodes (LNs) was performed in 36 primary patients with IB-IIB cervical cancer. The acquisition started 120–240min after 4 peritumoral injections of 99mTc-radiocolloids (150–300MBq in 0.4–1ml). We determined localization of LN with uptake of radiocolloids, type of lymph flow (mono-, bi-lateral) and lymph flow patterns (supraureteral paracervical, infraureteral paracervical and directly to para-aortic LNs).ResultsSLNs were visualized in 31 of 36 women. Bilateral lymph-flow was detected in 22 (71%), monolateral – in the other 9 (29%) cases. The distribution of SLNs was as follows: external iliac – 64.5%, internal iliac – 54.8%, obturator – 32.2%, common iliac – 35.5% and pre-sacral 3.2%. Para-aortic LNs were visualized in 5 (16.1%) patients. The supraureteral paracervical pattern of lymph flow was identified in 22, infraureteral paracervical – in 4 and their combination – in the other 5 women.ConclusionVisualization of an individual pattern of lymph flow from primary cervical cancer can be considered as a promising tool for optimization of the volume of irradiated regional LNs

Why do we need irradiation of internal mammary lymph nodes in patients with breast cancer: Analysis of lymph flow and radiotherapy studies

AimUsing clinical data and results of lymphoscintigraphy to calculate probability of internal mammary lymph node (IMLN) invasion by breast cancer (BC). To evaluate clinical value of lymphoscintigraphy as the guide for irradiation of IMLN.MethodsUsing the data of eight published studies that analyzed lymph flow from primary BC (4541pts) after intra-peri-tumoral injection of nanosized 99mTc-colloids we determined probability of lymph-flow from internal-central and external BC to IMLN. In 7 studies (4359pts) axillary staging was accompanied by IMLN biopsy (911pts) that helped us to estimate probability of IMLN metastatic invasion in relation to the status of axillary LN. Finally, we estimated probability of IMLN invasion by BC in five randomized and observation studies that analyzed effect of IMLN irradiation on overall survival (OS). We calculated possible gain in survival if they would be treated according to lymph-flow guided radiotherapy to IMLN.ResultsLymph-flow from internal/central BC to IMLN was mentioned in 35% from external lesions – in 16% cases. In women with negative axillary LN metastases in IMLN were revealed in 7.8%pts, in the case of positive axillary nodes average risk of IMLN invasion increased to 38.1%. Calculated probability of IMLN metastatic invasion in pts included in evaluated trials did not exceed 10%. If lymphoscintigraphy would drive decision about irradiation of IMLN than 72–78% of pts included in these studies would escape radiotherapy to IMLN. In the remaining 21–28%pts with lymph-flow to IMLN their irradiation probably would increase gain in OS from 1.0–3.3% to 4.3–16.8%.ConclusionLymphoscintigraphy can be used to optimize the strategy of IMLN irradiation

Accounting for the flexibility of nodes in the design of steel mesh dome

This paper presents the results of a study of the stress-strain state of a geodesic dome covering the planetarium designed in the city of Nizhny Novgorod. Four design schemes were created in the SCAD with different types of node modeling. A comparative analysis of the effect of the strain capacity of the “BrGTU” type unit on the stress-strain state of the dome cover has been carried out. The results are obtained on the change in the displacements of the structure nodes and internal forces in the dome bars, with rigid and hinged mates. The option of increasing the diameter of high-strength bolts to reduce the overall deformability of the system is considered. On the basis of the obtained results, it was concluded that it is necessary to take into account the strain capacity of the semirigid connections when designing mesh steel domes

Comparison of two treatment strategies for irradiation of regional lymph nodes in patients with breast cancer: Lymph flow guided portals versus standard radiation fields

Aim and BackgroundRadiotherapy being an essential part of breast cancer treatment, we evaluate various radiotherapy strategies in patients with breast cancer.Materials and methodsLymph node (LN) scintigraphy was performed in 172 primary patients with BC. LN visualization started 30–360[[ce:hsp sp="0.25"/]]min after intratumoral injection of 75–150 MBq of 99mTc-nanocolloids.Our standard recommendation for postoperative radiotherapy in patients with LN invasion by BC were as follows: for patients with external localization of tumour – breast[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]axillary (Ax)[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]sub-supraclavicular (SSCL) regions; with internal localization – all above[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]internal mammary nodes (IM). Proposed strategy of lymph flow guided radiotherapy is based on the assumption that only regions that contain ‘hot’ LNs must be included in a treatment volume.ResultsAmong 110 patients with external localization of BC, Ax LNs were visualized in all cases and in 62 patients it was the only region with ‘hot’ LN. Twenty-three patients (20.9%) had drainage to Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]SSCL, 12 (10.9%) – Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]IM, 13 (11.8%) – Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]SSCL[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]IM regions. After the visualization of lymph flow patterns, standard treatment volume was changed in 87/110 cases (79.1%): in 56.4%, reduced, in 22.7%, enlarged or changed.In 62 patients with tumours in internal quadrants, we revealed the following patterns of lymph-flow: only to the Ax region in 23 (37.1%); Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]IM, 13 (21%); Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]SSCL, 15 (24.2%); Ax[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]IM[[ce:hsp sp="0.25"/]]+[[ce:hsp sp="0.25"/]]ISSCL, 11 (17.7%) cases. After lymph-flow visualization, the standard irradiation volume was reduced in 53/62 (85.5%) cases.ConclusionVisualization of an individual lymph flow pattern from BC can be used for the optimization of standard fields used for irradiation of regional LNs

Justification of optimal design and technological parameters of needle discs of the combined working body

The aim of the research is to improve soil tillage quality using combined working bodies in surface cultivation. There are various designs of combined tillage units including passive cultivators and active rotor-tooth working bodies cultivating land. However, an analysis of design and technological parameters of modern cultivators shows that they have a cumbersome design, required much metal and their quality indicators do not meet soil cultivation requirements. The article presents results of the studies on the influence of geometric and technological parameters of an additional battery of needle discs on land tillage quality. Using the research results, the land tillage has been improved and combined working bodies have been developed

Removal of VOCs by Ozone: n-Alkane Oxidation under Mild Conditions

Volatile organic compounds (VOCs) have a negative effect on both humans and the environment; therefore, it is crucial to minimize their emission. The conventional solution is the catalytic oxidation of VOCs by air; however, in some cases this method requires relatively high temperatures. Thus, the oxidation of short-chain alkanes, which demonstrate the lowest reactivity among VOCs, starts at 250–350 °C. This research deals with the ozone catalytic oxidation (OZCO) of alkanes at temperatures as low as 25–200 °C using an alumina-supported manganese oxide catalyst. Our data demonstrate that oxidation can be significantly accelerated in the presence of a small amount of O3. In particular, it was found that n-C4H10 can be readily oxidized by an air/O3 mixture over the Mn/Al2O3 catalyst at temperatures as low as 25 °C. According to the characterization data (SEM-EDX, XRD, H2-TPR, and XPS) the superior catalytic performance of the Mn/Al2O3 catalyst in OZCO stems from a high concentration of Mn2O3 species and oxygen vacancies

Synthesis of a CFD benchmark exercise based on a test in the PANDA facility addressing the stratification erosion by a vertical jet in presence of a flow obstruction

The benchmark exercise discussed in this paper was conducted within the OECD/NEA project HYMERES. The specific experiment in the PANDA facility chosen for the present benchmark addresses the stratification erosion in a vessel where the upper region contained initially a mixture of steam and helium, and the remaining volume was filled with steam. The mixing is induced by a vertical steam jet, which originates from the exit of a circular pipe located below the bottom of the helium-rich layer. The stratification erosion process is somewhat slowed down by a small circular plate above the jet source. The exercise consisted of a blind phase, and an open phase. Two sets of blind simulations were requested: one set obtained using a “common model”, and a second set produced by a “best estimate” model. For the “common model”, a list of recommendations was given, whereas for the “best estimate” model, each participant was free to choose the modelling approach. The submitted results for the erosion times were in a large band, and especially the large differences in the results with the “common model” were not expected. The results of the best estimate simulations showed that the combination of mesh and modelling approach can lead to a wide spread of results. The most important difficulty in interpreting the results and finding the reason of the large deviations was the lack of information on the velocity field downstream of the obstruction. Therefore, for the open phase extended data from auxiliary, “zero” tests (for similar conditions but without helium layer) were provided to the participants to permit a more basic validation of their models, using a “multi-step approach”. The step-by-step validation permitted some progress with respect to some of the items identified in the blind benchmark. However, large discrepancies with data in the final analyses of the test are observed, which cannot be easily attributed to specific model deficiencies or insufficient detail of the mesh. These results raised some questions in relation to best practice guidelines for the use of Computational Fluid Dynamic (CFD) codes for containment analysis and indicated needs for further CFD-grade experiments

Magnetic resonance-guided focused ultrasound for patients with painful bone metastases: phase III trial results.

Pain due to bone metastases is a common cause of cancer-related morbidity, with few options available for patients refractory to medical therapies and who do not respond to radiation therapy. This study assessed the safety and efficacy of magnetic resonance-guided focused ultrasound surgery (MRgFUS), a noninvasive method of thermal tissue ablation for palliation of pain due to bone metastases. Patients with painful bone metastases were randomly assigned 3:1 to receive MRgFUS sonication or placebo. The primary endpoint was improvement in self-reported pain score without increase of pain medication 3 months after treatment and was analyzed by Fisher's exact test. Components of the response composite, Numerical Rating Scale for pain (NRS) and morphine equivalent daily dose intake, were analyzed by t test and Wilcoxon rank-sum test, respectively. Brief Pain Inventory (BPI-QoL), a measure of functional interference of pain on quality of life, was compared between MRgFUS and placebo by t test. Statistical tests were two-sided. One hundred forty-seven subjects were enrolled, with 112 and 35 randomly assigned to MRgFUS and placebo treatments, respectively. Response rate for the primary endpoint was 64.3% in the MRgFUS arm and 20.0% in the placebo arm (P < .001). MRgFUS was also superior to placebo at 3 months on the secondary endpoints assessing worst score NRS (P < .001) and the BPI-QoL (P < .001). The most common treatment-related adverse event (AE) was sonication pain, which occurred in 32.1% of MRgFUS patients. Two patients had pathological fractures, one patient had third-degree skin burn, and one patient suffered from neuropathy. Overall 60.3% of all AEs resolved on the treatment day. This multicenter phase III trial demonstrated that MRgFUS is a safe and effective, noninvasive treatment for alleviating pain resulting from bone metastases in patients that have failed standard treatments