Dosimetry comparison of 192Ir sources

192Ir sources besides being widely utilized in the field of conventional brachytherapy also find use in contemporary peripheral and coronal intravascular applications. In this study, the same Monte Carlo simulation code and input data were used to investigate differences between the dose rate distributions of the most commonly used 192Ir sources in the cm and mm distance range. Findings are discussed in view of differences in source and encapsulation dimensions as well as structural details. Results are presented in the AAPM TG-43 formalism, as generalized by AAPM TG-60, for five 192Ir HDR source designs as well as an LDR seed and an LDR wire source. Dose rate constants of the sources at r0 = 1 cm and r0 = 2 mm were found proportional to the corresponding geometry factors along the transverse source bisectors and an equation of the form lambda r0(cGyh(-1) U(-1)) = 1.12 x G(r0,90 degrees) provides results within clinical accuracy (less than 2%) for any 192Ir source. Radial dose functions do not depend significantly on source and encapsulation geometry and agree within 2% with that of a point 192Ir source. Anisotropy is of importance for accurate dosimetry at the cm distance range but it does not affect dose rate in the mm distance range significantly. At such short radial distances the source geometry factor defines the shape of isodose lines. Dose uniformity at given distances from the sources is strongly dependent on source dimensions as indicated by dose rate profiles in polar and Cartesian coordinates.     

Hydrocephalus in primary intradural spinal cord tumors: a systematic review of the literature in the pediatric population

Neurosurgical Review - Hydrocephalus in children with primary intradural spinal cord tumors is exceedingly rare. Herewith, we performed a systematic literature review to address epidemiology,...     

Superselective microcoil embolization of a traumatic pseudoaneurysm of the cavernosal artery

According to the literature, straddle injuries of the perineum may result in arteriosinusoidal fistula and secondary high-flow priapism. We report a case of a 23-year-old man who developed a traumatic pseudoaneurysm of the cavernosal artery, secondary to straddle injury, and presented with painless priapism. It was treated successfully with superselective microcoil embolization and the priapism resolved.     

Effect of bipolar electrode orientation on local electrogram properties

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Double versus single cervical cerclage for the prevention of preterm births

Objective: To evaluate the effectiveness double cervical cerclage in reducing antenatal complications and improve perinatal outcomes.

Methods: We searched Medline, Scopus, Clinicaltrials.org, The Cochrane Central Register of Controlled Trials and Google Scholar search engines.

Results: Six studies were included that involved 880 women. Double cerclage was significantly superior to single cerclage in reducing preterm births <34?weeks (734 cases, OR 0.59, 95% CI 0.40, 0.86) and preterm births <28?weeks (645 cases, OR 0.43, 95% CI 0.26–0.73). It also significantly increased the gestational age (380 cases, MD 2.63, 95% CI 0.87, 4.39). However, as a technique, it failed to improve the rates of preterm births <37?weeks (740 cases, OR 0.98, 95% CI 0.72, 1.34) the incidence of chorioamnionitis (740 cases, OR 0.83, 95% CI 0.51, 1.36) and the occurrence of preterm premature rupture of the membranes (796 cases, OR 1.32, 95% CI 0.95, 1.82).

Conclusions: It seems that double cerclage effectively increases the gestational age at delivery and decreases the rates of extremely premature births. However, as a procedure, it does not reduce the incidence of antenatal morbidity or the neonatal death rates. Further research is needed in the field as our meta-analysis is limited by the small number of enrolled studies.     

Oxytocin discontinuation after the active phase of labor is established

Despite the widespread usage of oxytocin, there is still no consensus on its mode of administration. The scope of the present meta-analysis was to assess the effect of oxytocin discontinuation after the active phase of labor is established on maternal fetal and neonatal outcomes. We searched Medline, Scopus, Popline, ClinicalTrials.gov and Google Scholar databases. Eight studies were finally retrieved, which involved 1232 parturient. We observed significantly decreased rates of cesarean sections among parturient that discontinued oxytocin (OR 0.51, 95% CI 0.35, 0.74) as well as decreased rates of uterine hyperstimulation (OR 0.33, 95% CI 0.19, 0.58). Similarly, cases of non-reassuring fetal heart rates were fewer among women that did not receive oxytocin after the establishment of the active phase of labor (OR 0.63, 95% CI 0.41, 0.97). Keeping in mind the aforementioned maternal and neonatal adverse effects that seem to result from infusion of oxytocin until delivery, future practice should aim towards its discontinuation after the establishment of the active phase of labor, as it does not seem to influence the total duration of labor. Future studies should aim towards specific populations of parturient in order to clarify whether different approaches are needed.