Browsing by Author "Razmilic, Dravna"

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    Contrast-enhanced mammography predicts pathological response after neoadjuvant chemotherapy in locally advanced breast cancer
    (2022) Canteros, Daniel; Walbaum, Benjamin; Córdova-Delgado, Miguel; Torrealba, Andrés; Reyes, Constanza; Navarro, María Elena; Razmilic, Dravna; Camus, Mauricio; Dominguez, Francisco; Navarrete, Orieta; Pinto, Mauricio P.; Pizarro, Gonzalo; Acevedo, Francisco; Sánchez, César
    Introduction: Recently, contrast-enhanced mammography (CEM) has emerged as a reliable alternative to breast magnetic resonance imaging (MRI) for the assessment of pathological response in breast cancer patients. Our study sought to determine the diagnostic accuracy of CEM to predict pathological complete response (pCR) in patients who received neoadjuvant chemotherapy (NACT). Methods: We retrieved the medical records of patients who underwent NACT at our institution. Using post-surgery pCR, morphological evidence and CEM enhancement tumours were classified as follows: 1) radiologic complete response (rCR); 2) functional radiological complete response (frCR); and 3) non-complete response. Initially, we used multivariate analyses adjusted by clinical variables and frCR or rCR to determine which variables affected pathological response. Then, CEM diagnostic accuracy to discriminate pCR was assessed using receiver operating characteristic curves in univariate and multivariate models including either frCR or rCR. Results: A total of 48 patients were included in our study. Most patients (68.7%) were hormone receptor (HR)+ and 41.6% (20) of the patients achieved pCR. Using univariate logistic regression analyses we found that HR status, HER2 status, rCR and frCR had a significant impact on CEM diagnostic accuracy. Exploratory analyses found that CEM sensitivity was higher for HR− tumours. Multivariate logistic regression analyses found 60% sensitivity, 92.9% specificity and 79.2% accuracy in a model that included clinical variables and rCR. Conclusion: CEM is a reliable alternative to high-cost, time-consuming breast MRI that predicts pCR in patients undergoing NACT; CEM diagnostic accuracy was higher among patients who harboured HR− tumours.
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    Enhancement of Visual Perception with Use of Dynamic Cues
    (RADIOLOGICAL SOC NORTH AMERICA, 2009) Andia, Marcelo E.; Plett, Johannes; Tejos, Cristian; Guarini, Marcelo W.; Navarro, Maria E.; Razmilic, Dravna; Meneses, Luis; Villalon, Manuel J.; Irarrazaval, Pablo
    Institutional review board approval and signed informed consent were not needed, as medical images included in public databases were used in this study. The purpose of this study was to improve the detection of microcalcifications on mammograms and lung nodules on chest radiographs by using the dynamic cues algorithm and the motion and flickering sensitivity of the human visual system (HVS). Different sets of mammograms from the Mammographic Image Analysis Society database and chest radiographs from the Japanese Society of Radiological Technology database were presented statically, as is standard, and in a video sequence generated with the dynamic cues algorithm. Nine observers were asked to rate the presence of abnormalities with a five-point scale (1, definitely not present; 5, definitely present). The data were analyzed with receiver operating characteristic (ROC) techniques and the Dorfman-Berbaum-Metz method. The video sequence generated with the dynamic cues algorithm increased the rate of detection of microcalcifications by 10.2% (P = .002) compared with that obtained with the standard static method, as measured by the area under the ROC curve. Similar results were obtained for lung nodules, with an increase of 12.3% (P = .0054). The increase in the rate of correct detection did not come just from the image contrast change produced by the algorithm but also from the fact that image frames generated with the dynamic cues algorithm were put together in a video sequence so that the motion sensitivity of the HVS could be used to facilitate the detection of low-contrast objects. (C) RSNA, 2009
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    Screen-detected breast cancer is associated with better prognosis and survival compared to self-detected/symptomatic cases in a Chilean cohort of female patients
    (2021) Walbaum, Benjamin; Puschel, Klaus; Medina, Lidia; Merino, Tomas; Camus, Mauricio; Razmilic, Dravna; Navarro, Maria Elena; Dominguez, Francisco; Cordova‑Delgado, Miguel; Pinto, Mauricio P.; Acevedo, Francisco; Sánchez, César
    Purpose The implementation of national breast cancer (BC) screening programs in Latin America has been rather inconsistent. Instead, most countries have opted for “opportunistic” mammogram screenings on the population at risk. Our study assessed and compared epidemiological, clinical factors, and survival rates associated with BC detected by screening (SDBC) or self-detected/symptomatic (non-SDBC) in Chilean female patients. Methods Registry-based cohort study that included non-metastatic BC (stage I/II/III) patients diagnosed between 1993 and 2020, from a public hospital (PH) and a private university cancer center (PC). Epidemiological and clinical data were obtained from medical records. Results A total of 4559 patients were included. Most patients (55%; n = 2507) came from PH and were diagnosed by signs/ symptoms (non-SDBC; n = 3132, 68.6%); these patients displayed poorer overall (OS) and invasive disease-free survival (iDFS) compared to SDBC. Importantly, the proportion of stage I and “luminal” BC (HR + /HER2 −) were significantly higher in SDBC vs. non-SDBC. Finally, using a stage/subset-stratified age/insurance-adjusted model, we found that nonSDBC cases are at a higher risk of death (HR:1.75; p < 0.001). In contrast, patients with PC health insurance have a lower risk of death (HR: 0.60; p < 0.001). Conclusion We confirm previous studies that report better prognosis/survival on SDBC patients. This is probably due to a higher proportion of stage I and luminal-A cases versus non-SDBC. In turn, the survival benefit observed in patients with PC health insurance might be attributed to a larger proportion of SDBC. Our data support the implementation of a systematic BC screening program in Chile to improve patient prognosis and survival rates.