1,068 research outputs found
Primary osteosarcoma of the spermatic cord: case report and literature review.
No full textPrimary osteosarcoma of the spermatic cord is a rare tumour with few mentions in the literature. A 59-year-old man presented with a large painless left inguinal and scrotal mass. The patient underwent excision of the mass, which arose from the spermatic cord. A left high dissection of the spermatic cord and radical orchiectomy due to associated atrophy of the left testicle were performed. Pathological findings were suggestive of spermatic cord osteosarcoma. The patient died eleven years later of metastatic lung disease. Spermatic cord osteosarcoma is an uncommon neoplasm and its preoperative diagnosis is very difficult. Any palpable suspicious mass of the cord should be investigated with ultrasonography before excision; CT scan and magnetic resonance imaging may be helpful in defining preoperative diagnosis and the extension of the mass into the neighbouring tissues. Surgical treatment of spermatic cord sarcomas in adults is via a radical orchiectomy with high dissection of the spermatic cord and en bloc excision of involved neighbouring tissues; overall 5- and 10-year survival rates are reported in the literature to be 75% and 55%, respectively
Long-term femoral vein central venous access in cancer patients.
No full textSubclavian percutaneous access with reservoir placement has been shown to be difficult or contraindicated in some patients. Of 465 cancer patients who required a port placement between January 1992 to January 1995, 41 (8.8%) had alternative percutaneous femoral access with a totally implantable port reservoir located in the abdomen because of the inaccessibility to subclavian or jugular veins and/or the presence of massive cutaneous metastases or severe radiodermitis in the upper part of the torso. Overall implant days was 9880, with an average of 241 days (range: 65-445). Ports were alternatively used for chemotherapy and nutritional purposes in 11 of 41 patients. Late morbidity causing the removal of the implanted ports was observed in two of 41 (4.9%) and 25 of 424 (5.9%) patients in the femoral and subclavian series, respectively (P = 0.86). The femoral percutaneous access for totally implantable port devices appears to be a safe alternative for cancer patients when subclavian and/or jugular vein catheterization and reservoir in the upper part of the torso is contraindicated
Theoretical Studies of Gamma-Ray Bursts with Swift
No full textGraduate student L.J. Gou , P. Meszaros, T. Abel and B. Zhang investigated the detectability of long GRB afterglows from very high redshifts, where bright reverse shock emission last longer in the observer frame, and its importance for detection and analysis purposes relative to the forward shock increases. They consider two different models for the GRB environment, based on current ideas about the redshift dependence of gas properties in galaxies and primordial star formation. They calculate the observed flux as a function of the redshift and observer time for typical GRB afterglows, taking into account intergalactic photoionization and Lyman-alpha absorption opacity as well as extinction by the Milky Way Galaxy. The fluxes in the X-ray and near IR bands are compared with the sensitivity of different detectors such as Chandra, Swift and JWST. They find that Chandra and Swift can potentially detect GRBs out to very high redshifts z above 13 and 30, respectively. In the K and M bands, the JWST and ground-based telescopes are potentially able to detect GRBs even one day after the trigger out to z approximately 16 and 33, if present. While the X-ray band is insensitive to the external density and to reverse shocks, the near IR bands provides a sensitive tool for diagnosing both the environment and the reverse shock components
PICC-PORT totally implantable vascular access device in breast cancer patients undergoing chemotherapy
No full textBackground and objectives: The increasing use of arm totally implantable vascular access devices for breast cancer patients who require chemotherapy has led to a greater risk of complications and failures and, in particular, to upper extremity deep vein thrombosis. This study aims to investigate the outcomes of the arm peripherally inserted central catheter-PORT technique in breast cancer patients. Methods: The peripherally inserted central catheter-PORT technique is an evolution of the standard arm-totally implantable vascular access device implant based on guided ultrasound venous access in the proximal third of the upper limb with subsequent placement of the reservoir at the middle third of the arm. A prospective study was conducted on 418 adult female breast cancer patients undergoing chemotherapy. The primary study outcome was peripherally inserted central catheter-PORT failure. Results: Median follow-up was 215 days. Complications occurred in 29 patients (6.9%) and failure resulting in removal of the device in 11 patients (2.6%). The main complication we observed was upper extremity deep vein thrombosis, 10 (2.4%); all patients were rescued by anticoagulant treatment without peripherally inserted central catheter-PORT removal. The main reason for removal was reservoir pocket infection: 4 (0.9%) with an infection rate of 0.012 per 1000 catheter days. Cumulative 1-year risk of failure was 3.6% (95% confidence interval, 1.3%–7.1%). With regard to the patients’ characteristics, body mass index <22.5 was the only significant risk for failure (p = 0.027). Conclusion: The peripherally inserted central catheter-PORT is a safe vascular device for chemotherapy delivery that achieves similar clinical results as traditional long-term vascular access devices (peripherally inserted central catheter and arm totally implantable vascular access device, in particular) in breast cancer patients
A new method to design energy-conserving surrogate models for the coupled, nonlinear responses of intervertebral discs
No full textThe aim of this study was to design physics-preserving and precise surrogate models of the nonlinear elastic behaviour of an intervertebral disc (IVD). Based on artificial force-displacement data sets from detailed finite element (FE) disc models, we used greedy kernel and polynomial approximations of second, third and fourth order to train surrogate models for the scalar force-torque -potential. Doing so, the resulting models of the elastic IVD responses ensured the conservation of mechanical energy through their structure. At the same time, they were capable of predicting disc forces in a physiological range of motion and for the coupling of all six degrees of freedom of an intervertebral joint. The performance of all surrogate models for a subject-specific L4 | 5 disc geometry was evaluated both on training and test data obtained from uncoupled (one-dimensional), weakly coupled (two-dimensional), and random movement trajectories in the entire six-dimensional (6d) physiological displacement range, as well as on synthetic kinematic data. We observed highest precisions for the kernel surrogate followed by the fourth-order polynomial model. Both clearly outperformed the second-order polynomial model which is equivalent to the commonly used stiffness matrix in neuro-musculoskeletal simulations. Hence, the proposed model architectures have the potential to improve the accuracy and, therewith, validity of load predictions in neuro-musculoskeletal spine models
Use of radioimmunoguided surgery after induction chemotherapy in locally advanced breast cancer.
No full textAbstract
Twenty-one patients with histologically proven locally advanced breast cancer (LABC) were treated with a combined modality approach based on primary chemotherapy and radical modified mastectomy followed by adjuvant chemotherapy. Surgery was performed by using radioimmunoguided surgery (RIGS) technique with the preoperative injection of Iodine-125 labeled monoclonal antibodies (MoAbs) B72.3 anti-TAG (11 patients, Group A) and FO23C5 anti-carcinoembryonic antigen (CEA; 10 patients, Group B). The role of RIGS was defined at surgery by using an intraoperative hand-held gamma-detecting probe (GDP) to locate the primary tumor, possible clinically occult multicentric foci and ipsilateral lymph node metastases. In Group A, RIGS correctly defined the primary tumor in seven out of 11 patients (63.3%) and was able to find multicentric tumors in two out of four patients (50%). Positive lymph nodes were identified by RIGS in three out of eight patients (37.5%). In Group B, patients RIGS correctly located the primary in 4/10 cases (40%); in two RIGS-positive cases, the tumor was clinically not evident after primary chemotherapy (yT0). RIGS correctly identified multicentric foci of tumor in one out of two cases (50%). Correct lymph nodal RIGS assessment was observed in three out of nine patients (33.3%). No RIGS false-positive findings occurred in the 21 patients included in the study. RIGS appears to be a reliable technique for the intraoperative diagnosis and staging of breast cancer with a potential role especially when conservative surgery is planned after primary chemotherapy in LABC
Results and lessons learned from the Generation IV SCWR-FQT comprehensive Monte Carlo computational benchmark
No full textA joint European Canadian Chinese development of a supercritical water-cooled small modular reactor technology has been in progress since September 2020 in the framework of a Horizon 2020 project called ECC-SMART. A specific work package has been dedicated to studying the design- and safety-related neutronic parameters and reactor physics behavior of the SCW-SMR to support the pre-conceptual design process. Three Monte Carlo codes, viz., MCNP, OpenMC, and Serpent, were selected for pre-conceptual design applications and code-to-code comparison within the Gen-IV SCWR-FQT reactor physics computational benchmark. The effective multiplication factor, the axial power distribution within the fuel, the axial three-group neutron flux distribution, and the spatial distribution of the energy deposition due to neutron and photon interactions were determined. In this paper, results and lessons learned from this study are presented, and useful considerations are summarized to provide guidance in obtaining consistent results among the three Monte Carlo codes
Predictive factors of non-sentinel lymph node involvement in patients with invasive breast cancer and sentinel node micrometastases
No full textPatient-related, tumor-related, and sentinel node (SN)-related factors have been identified with the aim of predicting non-SN status in patients with SN micrometastases. According to our previous experience, primary tumor size (p=0.005) and the presence of lymphovascular invasion (LVI) (p=0.000) significantly predicted non-SN status in patients with SN micrometastasis; moreover, non-SN metastases were never detected in patients with pT1a-1b, G1, and no LVI. A prospective assessment was undertaken in a validation set of 126 patients to confirm these findings. Univariate analysis indicated that primary tumor size (p=0.05), Scarff-Bloom-Richardson (SBR) grade (p=0.008), LVI (p=0.001), and the number of mitoses/mm(2) (p=0.01) were significant predictors of non-SN status. By logistic regression analysis, tumor size (p=0.03), LVI (p=0.001), grade (p=0.003) and the number of mitoses/mm(2) (p=0.01) were the only variables remaining in the model. Three subsets of patients were identified: i) 18.3% of patients (pT1, G1, and no LVI) had tumor-negative non-SN (no risk group); ii) 37.3% of patients (number of mitoses/mm(2) <10, SBR grade II-III) had a rate of tumor-positive non-SN <15% (intermediate risk); iii) 44.4% of patients had a mean rate of non-SN involvement of 46% (high risk). By these parameters, more than 50% of patients could be selectively spared unnecessary axillary lymph node dissection without staging or therapeutic benefit, especially in patients with well-differentiated pT1 tumors without LVI
Cytokeratin immunostaining reveals micrometastasis in negative hematoxylin-eosin lymph nodes of resected stage I-II (pT2-pT3) colorectal cancer.
No full text- …
