Arlette Elizalde

Embolization of nonvariceal portosystemic collaterals in transjugular intrahepatic portosystemic shunts

Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy.

Analysis of the changes induced by bevacizumab using a high temporal resolution DCE-MRI as prognostic factors for response to further neoadjuvant chemotherapy

Background Antiangiogenic drugs are being used in the treatment of locally advanced breast cancer. The effect of these drugs can be monitorized using high temporal resolution dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Purpose To evaluate changes in tumor microvasculature induced by bevacizumab and the usefulness of these changes predicting response to further neoadjuvant therapy. Material and Methods Seventy patients with locally advanced breast cancers were treated with one cycle of bevacizumab followed by neoadjuvant therapy, combining bevacizumab and cytotoxic chemotherapy. Two DCE-MRI were performed before and after bevacizumab. Changes in tumoral volume, pharmacodynamic curves, and pharmacokinetic variables (Ktrans, Kep, Ve, AUC90) in a ROI (ROI 1) encompassing the entire tumor and in another ROI (ROI 2) in the area of higher values of Ktrans were analyzed. Correlations with pathological response were made: parametrical and non-parametrical statistical analysis and ROC curves were used; a P < 0.05 was considered significant. Results Significant changes in tumoral volume (−4%), pharmacodynamic curves, and pharmacokinetic variables in ROI 1 Ktrans (−45%), Kep (−38%), Ve (−11%), and AUC90 (−44%) and ROI 2 Ktrans (−43%), Kep (−39%), Ve (−5%), and AUC90 (−45%) were observed after bevacizumab (P < 0.05). The effect of bevacizumab was not different between responders and non-responders (P > 0.05), and these changes could not predict response to further neoadjuvant therapy. Conclusion Bevacizumab induces remarkable tumoral volume, pharmacodynamics, and pharmacokinetic changes. However, these changes could not be used as early predictors for response to further neoadjuvant therapy.

Additional US or DBT after digital mammography: which one is the best combination?:

Background Digital mammography (DM) is widespread used for the detection of breast cancer, but its sensitivity drops in dense breasts. It is well known that additional breast ultrasound (US) and digital breast tomosynthesis (DBT) increase the sensitivity of DM. However, to our knowledge, there are no articles comparing the role of both additional techniques. Purpose To assess the diagnostic performance of DM and the different combinations of DM + additional DBT and DM + additional US in an enriched sample of patients. Material and Methods Retrospective study in an enriched sample of 1042 patients. Out of them, 84 patients had histologically proven malignant lesions and 258 patients had benign lesions. Finally 700 patients with normal explorations or benign lesions without biopsy confirmation (but stable for at least 12 months) were included. All of them underwent DM, US, and DBT examinations that were retrospectively reviewed by one expert radiologist, blinded to the final diagnoses. The DBT examinations were performed using one single view with wide angle (50°). The reader categorized the cases as benign (BI-RADS 1 or 2) or malignant (BI-RADS 3–5) for DM and the different combination of techniques. The sensitivity (SE) and specificity (SP) were calculated with the PEPI software and the ROC curves of the different techniques and combinations were calculated by using the SPSS 15.0 software. Results The SE and SP of DM were 69.05% and 88.20%, respectively. Additional DBT significantly increased the AUC of DM as well as additional US or the combination DM + DBT + US (P < 0.05). However there were no significant differences between the AUC of DM + US and DM + DBT (P = 0.7). Conclusion Additional US, DBT, or both, in combination with DM, significantly increased the AUC of DM. However, there were no significant differences between DM + DBT and DM + US.

The effect of the amount of peritumoral adipose tissue in the detection of additional tumors with digital breast tomosynthesis and ultrasound

Background Digital breast tomosynthesis (DBT) and ultrasound (US) can detect additional cancers after negative mammography. However, not all cancers are visible by both techniques. Purpose To study the role of the amount of peritumoral fat in the detection of additional cancers with DBT or US. Material and Methods One reader retrospectively reviewed 142 breast cancers in 109 women who underwent mammography, DBT, US, and magnetic resonance imaging (MRI). Two readers in consensus evaluated the additional cancers detected by US, DBT, or MRI, and classified them into four groups according to the amount of peritumoral adipose tissue: group I, >75% of peritumoral fat; group II, 50–74%; group III, 25–49%, and group IV, 0–24%. The detection of additional cancers by US and DBT with respect to the other imaging techniques was evaluated. Results Seventy-eight cancers were detected by mammography and the remaining 64 cancers were detected by DBT, US, or MRI. US and DBT detected 46 (71.8%) and 25 (39.06%) additional tumors, respectively. Statistical significance was only found in group IV (P < 0.01). Conclusion US detected more tumors than DBT in lesions surrounded by a small amount of fat. No significant differences were found between US and DBT in the detection of additional cancers in the other groups.

Evaluación de la reproducibilidad de un protocolo de resonancia magnética dinámica para el estudio farmacocinético de los tumores de mama

OBJECTIVE To evaluate the reproducibility of a protocol for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the pharmacokinetic study of breast tumors. MATERIAL AND METHODS We carried out this prospective study from October 2009 through December 2009. We studied 12 patients with stage ii-iii invasive breast cancer without prior treatment. Our centers research ethics committee approved the study. The 12 patients underwent on two consecutive days DCE-MRI with a high temporal resolution protocol (21 acquisitions/minute). The data obtained in an ROI traced around the largest diameter of the tumor (ROI 1) and in another ROI traced around the area of the lesions highest K(trans) intensity (ROI 2) were analyzed separately. We used parametric and nonparametric statistical tests to study the reproducibility and concordance of the principal pharmacokinetic variables (K(trans), Kep, Ve and AUC90). RESULTS The correlations were very high (r>.80; P<.01) for all the variables for ROI 1 and high (r=.70-.80; P<.01) for all the variables for ROI 2, with the exception of Ve both in ROI 1 (r=.44; P=.07) and in ROI 2 (r=.13; P=.235). There were no statistically significant differences between the two studies in the values obtained for K(trans), Kep and AUC90 (P>.05 for each), but there was a statistically significant difference between the two studies in the values obtained for Ve in ROI 2 (P=.008). CONCLUSIONS The high temporal resolution protocol for DCE-MRI used at out center is very reproducible for the principal pharmacokinetic constants of breast.

Impact on dose and image quality of a software-based scatter correction in mammography:

Background In 2014, Siemens developed a new software-based scatter correction (Progressive Reconstruction Intelligently Minimizing Exposure [PRIME]), enabling grid-less digital mammography. Purpose To compare doses and image quality between PRIME (grid-less) and standard (with anti-scatter grid) modes. Material and Methods Contrast-to-noise ratio (CNR) was measured for various polymethylmethacrylate (PMMA) thicknesses and dose values provided by the mammograph were recorded. CDMAM phantom images were acquired for various PMMA thicknesses and inverse Image Quality Figure (IQFinv) was calculated. Values of incident entrance surface air kerma (ESAK) and average glandular dose (AGD) were obtained from the DICOM header for a total of 1088 pairs of clinical cases. Two experienced radiologists compared subjectively the image quality of a total of 149 pairs of clinical cases. Results CNR values were higher and doses were lower in PRIME mode for all thicknesses. IQFinv values in PRIME mode were lower for all thicknesses except for 40 mm of PMMA equivalent, in which IQFinv was slightly greater in PRIME mode. A mean reduction of 10% in ESAK and 12% in AGD in PRIME mode with respect to standard mode was obtained. The clinical image quality in PRIME and standard acquisitions resulted to be similar in most of the cases (84% for the first radiologist and 67% for the second one). Conclusion The use of PRIME software reduces, in average, the dose of radiation to the breast without affecting image quality. This reduction is greater for thinner and denser breasts.