Three-dimensional treatment planning for vaginal cuff brachytherapy: dosimetric effects on organs at risk according to patients position.

PURPOSE: Aim of this study was to evaluate dose distribution within organs at risk (OARs) and planning target volume (PTV) based on three-dimensional treatment planning according to two different setup positions in endometrial carcinoma patients submitted to postoperative brachy-radiotherapy on vaginal vault. METHODS AND MATERIALS: Patients with endometrial cancer necessitating of adjuvant brachytherapy on vaginal vault were enrolled. Pelvic computed tomography studies were prospectively obtained in two different setup positions: extend legs (A position) and gynecological (B position). Contoured OARs were bladder, rectum, and small bowel. The PTV was identified as applicator's surface with an isotropic 5-mm margin expansion. Radiation dose delivered in 1 cc (D1cc) and 2 cc (D2cc) of OAR were calculated. RESULTS: Coverage of PTV and values of D1cc and D2cc obtained for bladder and small bowel were similar in the two positions. For rectum, both D1cc and D2cc had statistically significant lower values in A with respect to B position. CONCLUSIONS: Both in A and B positions, radiation doses delivered do not exceed the dose constraints. However, A setup seems to significantly reduce doses to rectum while obtaining the same PTV coverage. The findings from our study provide evidence supporting the use of A position setup for delivering vaginal vault brachytherapy.

Biomolecular characterization of wild sicilian oregano: phytochemical screening of essential oils and extracts, and evaluation of their antioxidant activities.

An extensive survey of wild Sicilian oregano was made. A total of 57 samples were collected from various sites, followed by taxonomic characterization from an agronomic perspective. Based on morphological and production characteristics obtained from the 57 samples, cluster analysis was used to divide the samples into homogeneous groups, to identify the best biotypes. All samples were analyzed for their phytochemical content, applying a cascade-extraction protocol and hydrodistillation, to obtain the non volatile components and the essential oils, respectively. The extracts contained thirteen polyphenol derivatives, i.e., four flavanones, seven flavones, and two organic acids. Their qualitative and quantitative characterization was carried out by LC/MS analyses. The essential oils were characterized using a combination of GC-FID and GC/MS analyses; a total of 81 components were identified. The major components of the oils were thymol, p-cymene, and γ-terpinene. Cluster analysis was carried out on both phytochemical profiles and resulted in the division of the oregano samples into different chemical groups. The antioxidant activity of the essential oils and extracts was investigated by the Folin-Ciocalteau (FC) colorimetric assay, by UV radiation-induced peroxidation in liposomal membranes (UV-IP test), and by determining the O(2)(∙-)-scavenging activity.

A method to evaluate the dose increase in CT with iodinated contrast medium.

PURPOSE: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. METHODS: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. RESULTS: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. CONCLUSIONS: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical protocols employ multiple scans at different circulatory phases after administration of contrast medium, such a method can be useful to evaluate the total dose to the patient, also in view of potential clinical protocol optimizations.

Enlarged axillary nodes and position of the arms in axillary irradiation--a computed tomography and magnetic resonance imaging evaluation.

The purpose of this study was to evaluate the axillary node displacement away from chest wall and their anatomical location in relation to the humeral head, according to the position of the arms, when the axilla is the site of enlarged nodes. In 13 patients with enlarged axillary nodes, the anatomical span of the nodes according to two arms positions, akimbo (A) and up over the head (U), was prospectively evaluated using computed tomography (CT) and magnetic resonance imaging (MRI). The nodes were classified into two groups, i.e. the lower and upper groups. The mean distances of the lower node group from the chest wall when the patients were in A, and U positions were 3 cm and 6.4 cm, respectively (p = 0.002). The upper group nodes showed a smaller difference in the distance from the chest wall: in A position, mean 2.1 cm; in U position 2.8 cm (p = 0.03). In U position, there was always a node of the lower group that was displaced in front of the humeral head. This study demonstrates the displacement of enlarged axillary nodes according to the position of the arms. In patients with axillary node involvement, CT planning should be considered when they have their arms held up over their heads.