1181. Large ring test for evaluation of restrained shrinkage cracking : calibration and experimental trialZhongyu Xu, Lucija Hanžič, Harry Asche, Jurij Karlovšek, 2024, original scientific article Abstract: The durability of shotcrete tunnel linings is significantly affected by restrained shrinkage cracking. Given the unique characteristics of shotcrete applied in tunnel linings, especially when dealing with accelerated shotcrete containing reinforcement fibres, it is necessary to upscale the ring test commonly used. This paper presents a comprehensive experiment using large ring tests with cast concrete to investigate the impact of upscaling ring test geometry. The two ring specimens demonstrated comparable cracking age (22 days) and strain measured in the steel ring, suggesting that consistent results can be obtained through the proposed instrumentation, calibration, and correction methods. Moreover, the estimated induced tensile stresses of the concrete rings (2.8 and 2.7 MPa) are slightly lower than the predicted tensile strength (3.3 MPa) at the age of cracking, which indicates that some driving forces contributing to restrained shrinkage cracking were not indicated in the strain gauge readings. Furthermore, the study identified multi-crack formation and additional potential causes for crack initiation, which include self-restraint due to the moisture gradient in the vertical direction, deflection of the concrete ring caused by its self-weight, and friction on the contact surface of the support. Therefore, optimising the geometry of the ring specimens and the apparatus is imperative to minimise additional driving forces and unmeasurable restraints for crack initiation, especially when employing the stress rate method to assess cracking potential.
Keywords: concrete, restrained shrinkage, tunnel lining, large ring test
Published in DiRROS: 22.07.2024; Views: 278; Downloads: 230
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1182. Can dynamic imaging, using 18F-FDG PET/CT and CT perfusion differentiate between benign and malignant pulmonary nodules?Aleksander Marin, John T. Murchison, Kristopher M. Skwarski, Adriana A.S. Tavares, Alison Fletcher, William A. Wallace, Vladka Salapura, Edwin J.R. Van Beek, Saeed Mirsadraee, 2021, original scientific article Abstract: Background. The aim of the study was to derive and compare metabolic parameters relating to benign and ma- lignant pulmonary nodules using dynamic 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) PET/CT, and nodule perfu- sion parameters derived through perfusion computed tomography (CT). Patients and methods. Twenty patients with 21 pulmonary nodules incidentally detected on CT underwent a dynamic 18F-FDG PET/CT and a perfusion CT. The maximum standardized uptake value (SUVmax) was measured on conventional 18F-FDG PET/CT images. The influx constant (Ki) was calculated from the dynamic 18F-FDG PET/CT data using Patlak model. Arterial flow (AF) using the maximum slope model and blood volume (BV) using the Patlak plot method for each nodule were calculated from the perfusion CT data. All nodules were characterized as malignant or benign based on histopathology or 2 year follow up CT. All parameters were statistically compared between the two groups using the nonparametric Mann-Whitney test. Results. Twelve malignant and 9 benign lung nodules were analysed (median size 20.1 mm, 9-29 mm) in 21 patients (male/female = 11/9; mean age +- SD: 65.3 +- 7.4; age range: 50-76 years). The average SUVmax values +- SD of the benign and malignant nodules were 2.2 +- 1.7 vs. 7.0 +- 4.5, respectively (p = 0.0148). Average Ki values in benign and malig- nant nodules were 0.0057 +- 0.0071 and 0.0230 +- 0.0155 min-1, respectively (p = 0.0311). Average BV for the benign and malignant nodules were 11.6857 +- 6.7347 and 28.3400 +- 15.9672 ml/100 ml, respectively (p = 0.0250). Average AF for the benign and malignant nodules were 74.4571 +- 89.0321 and 89.200 +- 49.8883 ml/100g/min, respectively (p = 0.1613). Conclusions. Dynamic 18F-FDG PET/CT and perfusion CT derived blood volume had similar capability to differentiate benign from malignant lung nodules.
Keywords: CT perfusion, malignant pulmonary nodules, benign pulmonary nodules
Published in DiRROS: 22.07.2024; Views: 278; Downloads: 107
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1185. Breast cancer during pregnancy : retrospective institutional case seriesErika Matos, Tanja Ovčariček, 2021, original scientific article Abstract: Pregnancy associated breast cancer is a rare disease. It presents a unique entity of breast cancer with aggressive phenotype. The main aim was to evaluate how the international guidelines were followed in daily practice. Patients and methods. Data concerning patients% and tumours% characteristics, management, delivery and ma-ternal outcome were recorded from institutional electronic database. In this paper a case series of pregnant breast cancer patients treated at single tertiary institution between 2007 and 2019 are presented and the key recommenda-tions on managing such patients are summarized.Results. Fourteen patients met the search criteria. The majority of tumours were high grade, triple negative or HER2 positive, two patients were de novo metastatic. Treatment plan was made for each patient by multidisciplinary team. Eight patients were treated with systemic chemotherapy with no excess toxicity or severe maternal/fetal adverse ef-fects. In all but two patients, delivery was on term and without major complications. Only one event, which was not in whole accordance with international guidelines, was identified. It was the use of blue dye in one patient.Conclusions. Women with pregnancy associated breast cancer should be managed like non-pregnant breast cancer patients and should expect a similar outcome, without causing harm to the unborn child. To achieve a good outcome in pregnancy associated breast cancer, a multidisciplinary approach is mandatory.
Keywords: breast cancer, pregnancy, clinical characteristics, therapeutic strategy
Published in DiRROS: 22.07.2024; Views: 278; Downloads: 92
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1187. Adverse events during immunotherapy in Slovenian patients with metastatic melanoma reveal a positive correlation with better treatment outcomesTanja Mesti, Vid Čeplak Mencin, Biljana Mileva Boshkoska, Janja Ocvirk, 2021, original scientific article Abstract: Background. Immunotherapy with CTLA-4 inhibitors and PD1 checkpoint inhibitors has initiated a breakthrough in the treatment and prognosis of patients with metastatic melanoma. The survival of these patients has increased from the expected survival time of less than 12 months to at least forty months. However, immunotherapy with either anti-CTLA-4 antibodies or PD1 inhibitors alone or in combination has a broad palette of significant immune-related adverse events. The aim of the study was to assess the correlation of immune-related adverse events with treatment outcomes defined as significant differences in the overall response rate (ORR) and progression-free survival (PFS) of patients, who developed immune-related adverse events during immunotherapy.Patients and methods. A retrospective analysis of patients with metastatic melanoma treated with immuno-therapy in 2020 at the Oncology Institute of Ljubljana was performed. Only patients with radiological evaluation of the immunotherapy response were included. The patients were divided into two cohorts: a cohort of patients with immune-related adverse events (irAE group) and a cohort of patients with no immune-related adverse events (NirAE group). Significantly better overall response and progression-free survival in the irAE cohort defined the primary aim of our study. To investigate the differences in progression-free survival between the irAE cohort and NirAE cohort, we used survival analysis. In particular, a Cox proportional hazards model with covariates of time to progression and adverse events was used for survival analysis. The Kruskal-Wallis H-test was applied, and a p-value of p <= 0.05 was considered the cut-off point for a statistically significant difference between the groups.Results. Among the 120 patients treated with immunotherapy, radiological response evaluation was performed for 99 patients: 38 patients in the irAE cohort and 61 patients in the NirAE cohort. The ORRs for the irAE and NirAE cohorts were 57% and 37%, respectively. The PFS was significantly better for the irAE cohort (301.6 days) than for the NirAE co-hort (247.29 days). The results of the survival regression analysis showed a significant increase in the survival probability from less than 60% for the NirAE cohort to almost 80% for the irAE cohort.Conclusions. Patients with metastatic melanoma treated with immunotherapy who developed immune-related adverse events showed better treatment outcomes with longer times to disease progression and better overall re-sponse rates than patients treated with immunotherapy who did not develop immune-related adverse events, with a significant increase in the survival probability from less than 60% for the NirAE cohort to almost 80% for the irAE cohort.
Keywords: immune related adverse events, immunotherapy, metastases, melanoma
Published in DiRROS: 22.07.2024; Views: 265; Downloads: 149
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1188. The importance of flaps in reconstruction of locoregionally advanced lateral skull-base cancer defects : a tertiary otorhinolaryngology referral centre experienceDomen Vozel, Peter Pukl, Aleš Grošelj, Aleksandar Aničin, Primož Strojan, Saba Battelino, 2021, original scientific article Abstract: Background. The aim of the study was to identify the value of extensive resection and reconstruction with flaps in the treatment of locoregionally advanced lateral skull-base cancer.Patients and methods. The retrospective case review of patients with lateral skull-base cancer treated surgically with curative intent between 2011 and 2019 at a tertiary otorhinolaryngology referral centre was made. Results. Twelve patients with locoregionally advanced cancer were analysed. Lateral temporal bone resection was performed in nine (75.0%), partial parotidectomy in six (50.0%), total parotidectomy in one (8.3%), ipsilateral selective neck dissection in eight (66.7%) and ipsilateral modified radical neck dissection in one patient (8.3%). The defect was reconstructed with anterolateral thigh free flap, radial forearm free flap or pectoralis major myocutaneous flap in two patients (17.0%) each. Mean overall survival was 3.1 years (SD = 2.5) and cancer-free survival rate 100%. At the data collection cut-off, 83% of analysed patients and 100% of patients with flap reconstruction were alive. Conclusions. Favourable local control in lateral skull-base cancer, which mainly involves temporal bone is achieved with an extensive locoregional resection followed by free or regional flap reconstruction. Universal cancer registry should be considered in centres treating this rare disease to alleviate analysis and multicentric research.
Keywords: temporal bone, microsurgery, parotid region, free tissue flaps, neoplasm staging, ear
Published in DiRROS: 22.07.2024; Views: 312; Downloads: 174
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1190. Trends in population-based cancer survival in SloveniaVesna Zadnik, Tina Žagar, Katarina Lokar, Sonja Tomšič, Amela Duratović Konjević, Branko Zakotnik, 2021, original scientific article Keywords: cancer burden, cancer survival, time trend, cancer registry
Published in DiRROS: 22.07.2024; Views: 253; Downloads: 164
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