Monte Carlo estimation of absorbed dose to organs in diagnostic radiology

A method to estimate the absorbed dose to organs in diagnostic radiology was developed. The method is based on Monte Carlo techniques and has been prepared as a tool that can be adapted to any type of examination or view and which is readily available since it is used in a personal computer and not as a list of numerical results. It has been developed with the EGS4 system for static examinations in diagnostic radiology. A study was made of the absorbed doses to different parts of the head during a conventional x-ray examination. Simulation was performed for different arrangements (monoenergetic beam, spectrum, different number of histories, different size of cells, etc.). The method is capable of estimating doses in agreement with those measured experimentally and those obtained by other authors.     

Predicting unconsciousness after propofol administration: qCON,BIS, and ALPHA band frequency power

During anesthesia induction with propofol the level of arousal progressively decreases until reaching loss of consciousness (LOC). In addition, there is a shift of alpha activity from parieto-occipital to frontal zones, defined as anteriorization. Whilst monitoring LOC and anteriorization would be useful to improve propofol dosage and patient safety, the current devices for anesthetic depth monitoring are unable to detect these events. The aim of this study was to observe LOC and anteriorization during anesthesia induction with propofol by applying electrodes placed in the frontal and parietal areas. Bispectral index (BIS) and quantium consciousness index (qCON) monitors were simultaneously employed. BIS? and qCON sensors were placed in the frontal and parieto-occipital regions of 10 alopecic patients who underwent anesthesia with propofol, alfentanil, and remifentanil. The initial biophase target of propofol was 2.5 mcg/mL which was gradually increased until reaching LOC. Wilcoxon signed-rank test was used to study differences in alpha power and qCON/BIS indices along the study; and Pk value to evaluate predictive capability of anteriorization of BIS, qCON, and alpha waves. Parietal BIS and qCON values became significantly higher than frontal values 15 min after loss of eye reflex. Anteriorization was observed with both monitors. Pk values for BIS and qCON were strongly predictive of frontal alpha absolute power. During anesthesia induction with propofol it is possible to identify anteriorization with BIS and qCON in the frontal and parieto-occipital regions. Both indices showed different patterns which need to be further studied.

     

New screening method for lung cancer by detecting volatile organic compounds in breath

Lung cancer is a frequent cause of cancer-related deaths in the world. There is no valid screening process and this limits its detection to the late stages, with consequently high mortality rates. Volatile organic compounds (VOC) are chemical compounds (mainly the products of cell catabolism) found as gases in the human breath. Different methods have been developed to analyse VOCs and to compare them in healthy subjects and lung cancer patients. In this review, we summarise the different techniques used to analyse VOC. Many reports have been published with promising results similar to those achieved with accepted screening methods such as mammography. These methods show good perspectives on lung cancer screening. Supported by an unrestricted educational grant from Roche Farma S.A.     

Breast-feeding in Navarra

The state of breast-feeding in our autonomous community between 1986 and 1993 is reviewed. Two comparable Navarrese neonatal groups from our main maternity hospital are studied. The prevalence of the different types of breast-feeding at the time of discharge from the maternity hospital is compared, as well as monthly rates until the sixth month of life. The following conclusions can be drawn from this study: 1. The category of breast-feeding in Navarra is type 1 of the WHO. 2. Breast-feeding is abandoned in an early and massive way throughout the first six months of life in Navarra, with figures for this practice being undetectable by the sixth month. 3. There are barely any significant differences between the figures for 1986 and 1993.     

Clinical benefit in Phase-I trials of novel molecularly targeted agents: does dose matter?

Phase-I trials traditionally involve dose-escalation to determine the maximal tolerated dose (MTD). With conventional chemotherapy, efficacy is generally deemed to be dose-dependent, but the same may not be applicable to molecularly targeted agents (MTAs). We analysed consecutive patients included in Phase-I trials at the Royal Marsden Hospital from 5 January 2005 to 6 June 2006. We considered only trials of monotherapy MTAs in which the MTD was defined. Three patient cohorts (A, B, and C) were identified according to the dose received as a percentage of the final trial MTD (0–33%, 34–65%, >66%). Potential efficacy was assessed using the non-progression rate (NPR), that is, complete/partial response or stable disease for at least 3 months by RECIST. A total of 135 patients having progressive disease before enrolment were analysed from 15 eligible trials. Median age was 57 years (20–86); male : female ratio was 1.8 : 1. Cohort A, B, and C included 28 (21%), 22 (16%), and 85 (63%) patients; NPR at 3 and 6 months was 21% and 11% (A), 50% and 27% (B), 31% and 14% (C), respectively, P=0.9. Median duration of non-progression (17 weeks; 95% CI=13–22) was not correlated with the MTD level, P=0.9. Our analysis suggests that the potential for clinical benefit is not confined to patients treated at doses close to the MTD in Phase-I trials of MTAs.     

From targeted therapy in ovarian cancer to personalizing therapy for ovarian cancer

Epithelial ovarian carcinoma (EOC) is the most important cause of gynecological cancer-related mortality in Western societies. The majority of patients with ovarian cancer present with advanced disease, and in this group of patients, the median survival time is only 3 years. New treatment approaches are, therefore, required to improve outcome in this disease. Two strategies have emerged with promising results: poly ADP-ribose polymerase enzyme (PARP) inhibitors and targeting angiogenesis. The challenge remains to develop a convenient and accurate method to identify patients likely to benefit from targeted therapy.