Applied Radiation Dose Research Articles

949 INFLUENCE ADJUVANT VS. SALVAGE RADIOTHERAPY ON CONTINENCE AFTER RADICAL PROSTATECTOMY

You have accessJournal of UrologyProstate Cancer: Advanced III1 Apr 2012949 INFLUENCE ADJUVANT VS. SALVAGE RADIOTHERAPY ON CONTINENCE AFTER RADICAL PROSTATECTOMY Joanne Nyarangi-Dix, Johannes Steimer, Hildegard Jakobi, Sascha Pahernik, Boris Hadaschik, and Markus Hohenfellner Joanne Nyarangi-DixJoanne Nyarangi-Dix Heidelberg, Germany More articles by this author , Johannes SteimerJohannes Steimer Heidelberg, Germany More articles by this author , Hildegard JakobiHildegard Jakobi Heidelberg, Germany More articles by this author , Sascha PahernikSascha Pahernik Heidelberg, Germany More articles by this author , Boris HadaschikBoris Hadaschik Heidelberg, Germany More articles by this author , and Markus HohenfellnerMarkus Hohenfellner Heidelberg, Germany More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1047AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Adjuvant radiotherapy (ART) in high risk and salvage radiation therapy (SRT) in case of biochemical recurrence are common settings for EBRT after radical prostatectomy (RP). We primarily evaluated the effect of both approaches on continence. METHODS Upon authorization by our institutional review board we identified 309 men from the Heidelberg prospective tumour data bank. ART was defined as RT < 4 months and SRT as RT > 4 months after RP. We retrieved data on pre-, postoperative patient and tumour characteristics as well as postoperative therapies like RT from our institutional prospective tumour data bank. A telephone survey for evaluation of continence was done using the ICIQ-SF-Questionnaire. Study subjects were also further questioned e.g. on whether present continence was similar, better or worse than the situation prior to RT. Analysis was made with the IBM-SPSS software and Pearson Chi-square, Students′ t-test and Fischer′s exact tests. RESULTS 128 received ART and the other 181 SRT. Mean age of all patients at the time of RT was 65.4 (sd 6.2) yrs. Statistically significant differences in the distribution between the 2 groups were found in age at RT, preoperative prostate volume, post-RT-PSA, progression free survival , lymph node status, Gleason score and surgical margins. The difference in the distribution of applied radiation dose, age at RP, technique of RP, preoperative PSA-Value, length of RT, cancer specific survival, pre-RT-continence was not statistically significant. Form and overall grade continence before and after ART and SRT was also not statistically significant. In a sub-analysis, only 2% of the patients, all from the ART group, indicated an improvement of continence in the period after RT; this was statistically, significant. The other 98% reported unchanged or worsened continence. There was no significant difference in this distribution between the 2 groups. CONCLUSIONS According to our literature review of the past 10 years, this is the first study specifically analysing the effect of ART vs. SRT on continence. The time of RT seems to have no significant influence on continence after RP. At the same time, maintenance of the natural course of post-prostatectomy continence including spontaneous improvement seems possible. Should this thesis be confirmed in prospective studies, early ART and intraoperative RT-regimes can be safely evaluated with the goal of improving survival of high risk prostate cancer without compromising continence. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e386 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joanne Nyarangi-Dix Heidelberg, Germany More articles by this author Johannes Steimer Heidelberg, Germany More articles by this author Hildegard Jakobi Heidelberg, Germany More articles by this author Sascha Pahernik Heidelberg, Germany More articles by this author Boris Hadaschik Heidelberg, Germany More articles by this author Markus Hohenfellner Heidelberg, Germany More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Evaluation of microbial loads, physical characteristics, chemical constituents and biological properties of radiation processed Fagonia arabica

Whole plant of Fagonia arabica with 3 different particle sizes (30, 50 and 70 mesh) were exposed to gamma radiation doses of 1–10kGy from a Cobalt 60 source. A series of tests was performed in order to check the feasibility of irradiation processing of the plant. The applied radiation doses did not affect (P<0.05) pH and antimicrobial activities of the plant. The total weight of the dry extracts in methanol as well as water was found increased with irradiation. The irradiated samples showed significant increase in phenolic content and free radical scavenging activity using DPPH. Shortly after irradiation (on the day of radiation treatment) high amounts of free radicals were detected in the irradiated plant samples and the chemiluminescence measurements were generally found to be dose dependent. Maximum luminescence intensity was observed in case of samples with mesh size of 30 for all the radiation doses applied. After a period of one month the chemiluminescence signals of the irradiated samples approximated those of the controls. The study suggests that gamma irradiation treatment is effective for quality improvement and enhances certain beneficial biological properties of the treated materials.

Therapeutic results and safety of postoperative radiotherapy for keloid after repeated Cesarean section in immediate postpartum period

PurposeTo evaluate the effectiveness and safety of postoperative radiotherapy for the treatment of keloid scars administered immediately after Cesarean section.Materials and MethodsA total of 26 postpartum patients with confirmed keloids resulting from previous Cesarean sections received either 12 or 15 Gy radiotherapy. The radiotherapy was divided into three 6 MeV electron beam fractions administered during the postpartum period immediately following the final Cesarean section. To evaluate ovarian safety, designated doses of radiation were estimated at the calculated depth of the ovaries using a solid plate phantom and an ionization chamber with the same lead cutout as was used for the treatment of Cesarean section operative scars and a tissue equivalent bolus.ResultsIn total, the control rate was 77% (20 patients), while six (23%) developed focally elevated keloids (ranging from 0.5 to 2 cm in length) in the middle of the primary abdominal scar. Five patients experienced mild hyperpigmentation. Nonetheless, most patients (96%) were satisfied with the treatment results. The estimated percentage of the applied radiation doses that reached the calculated depth of the ovaries ranged from 0.0033% to 0.0062%.ConclusionWhen administered during the immediate postpartum period, postoperative electron beam radiotherapy for repeated Cesarean section scars is generally safe and produces good cosmetic results with minimal toxicity.

Niedrigdosis-Computertomografieprotokoll zur Detektion von Kokain-Bodypacks: Klinische Evaluation und rechtliche Aspekte

To discuss the juridical basis for CT examinations of cocaine body packers and to evaluate the clinical implementation of a tube current reduction-based low-dose CT protocol. A literature search was performed to discuss the legal basis regarding the problem, the procedures, the potential harm and the proportionality. Retrospective evaluation of 8 patients who had undergone a low-dose CT scan (body mass index < 25 kg/m(2) 30 mAs; > 25 kg/m(2) 60 mAs) during the time period from February until October 2009 in order to exclude or to assess remaining cocaine body packs was approved by the institutional review board. The detectability and condition of the body packs were analyzed. Effective doses were calculated. German jurisdiction does not distinguish between plain film X-ray and CT examinations. Both plain film X-ray and CT examination require a judicial warrant. However, examination results might still remain valid if a warrant was not requested. In 8 examinations (30 mAs n = 3, 60 mAs n = 5, mean BMI 25.9 ± 3.2) a total of 34 body packs were correctly identified. The mean density of the body packs was 74.4 ± 31.9 HU (range 17-154 HU) with a cocaine content between 22.5% and 72.8%. The mean estimated radiation dose was 2.23 ± 0.72 mSv. Although medical legal aspects do not specify the diagnostic procedure to be performed, the high diagnostic accuracy and applied radiation dose reduction could establish low-dose CT as the method of choice for detecting cocaine body packs, thereby potentially avoiding future legal problems.

Phantom and cadaver measurements of dose and dose distribution in micro-CT of the chest in mice

Micro-computed tomography (CT) allows high-resolution imaging of the chest in mice for small animal research with a significant radiation dose applied. To report on measurement of the applied radiation dose using different scan protocols in micro-CT of the chest in mice. Repetitive dose measurements were performed for four different micro-CT protocols (with/without respiratory gating) and for micro-CT fluoroscopy used for chest imaging. Measurements were carried out using thermoluminescence dosimeters (TLD) in mouse cadavers and in a PMMA phantom allowing measurement of the radiation dose in the direct path of rays and assessment of scattered radiation. The dose measured inside and outside the chests of the cadavers varied between 190 und 210 mGy, respectively. The expected mean doses in mice in the direct path of rays for the four examined micro-CT protocols varied between 170 and 280 mGy. The mean values for 1 and 5 minutes of fluoroscopy were 17 mGy and 105 mGy, respectively. The measured dose values are similar to the dose values for micro-CT of the chest reported so far. A relevant dose can be delivered by micro-CT of the chest, which could possibly interact with small animal studies. Therefore, the applied dose for a specific protocol should be known and adverse radiation effects be considered.

Interaction of 8 MeV Electron beam with P31 &amp;lt;i&amp;gt;Bombyx mori&amp;lt;/i&amp;gt; Silk Fibers

The 8 MeV electron radiation-induced changes in physical and thermal properties in P31 (Bombyx mori) silk fibers were investigated and has been correlated with the applied radiation doses. Irradiation of fiber samples were carried out in dry air at room temperature using an electron beam accelerator for varied radiation doses in the range of 0-100 kGy. Physical properties of the irradiated silk fibers were studied using XRD, FT-IR and thermogravimetric analysis (TGA) and compared with unirradiated fiber sample. Interesting results are discussed in this report.

Effect of marble particle size and gamma irradiation on mechanical properties of polymer concrete

AbstractEffects of gamma radiation and the marble particle size on compressive properties and the dynamic elastic modulus of polymer concretes (PCs) were studied. The PCs had a composition of 30 % of unsaturated polyester resin and 70 wt. % of marble as aggregate. Different types of PC were developed with the combination of one, two or three marble-particle sizes. The materials were submitted to 5, 10, 50, 100 and 150 kGy of radiation doses. Both the compressive properties and the dynamic elastic modulus values depend on the combination of the marble-particle sizes and the applied radiation dose. Higher numbers of dispersed particles per unit volume provide more resistance to crack propagation. On the other hand, longer particles give more reinforcement. As a result of these two competing effects, medium size marble particles provide the highest compression modulus

High-Pitch 128-Slice Dual-Source CT for the Assessment of Coronary Stents in a Phantom Model

To evaluate the quality of stent lumen delineation using dual-source computed tomography (DSCT) in the standard-pitch mode (SP) as compared to the high-pitch mode (HP) in a phantom study. Forty different coronary stents placed in plastic tubes filled with contrast agent were imaged with a second generation DSCT system in a SP (pitch 0.23) and HP (pitch 3.4) mode in orientations of 0°, 45°, and 90° relative to the z-axis. Two observers independently measured the in-stent lumen and the attenuation values in the center of the stents. The artificial lumen narrowing (ALN) was calculated using the measured in-stent lumen and the nominal diameter of the plastic tube. Interobserver correlation was excellent for in-stent lumen (0.86) and attenuation measurements (0.91). There was no significant difference neither for ALN (SP: 54.7-62.8%; HP: 55.8-64.0%) nor attenuation (SP: 356-395 Hounsfield units [HU]; HP: 352-384 HU) between SP and HP mode. For both modes, the orientation of the stent relative to the z-axis significantly affected ALN and attenuation (each P < .001). CT volume dose index was significantly lower using HP mode as compared to SP mode (P < .001). The HP mode in DSCT provides visualization of the coronary in-stent lumen comparable to that measured in SP mode while reducing applied radiation dose in a stationary phantom model.

Computer-assisted periacetabular screw placement: Comparison of different fluoroscopy-based navigation procedures with conventional technique

The current gold standard for operatively treated acetabular fractures is open reduction and internal fixation. Fractures with minimal displacement may be stabilised by minimally invasive methods such as percutaneous periacetabular screws. However, their placement is a demanding procedure due to the complex pelvic anatomy. The aim of this study was to evaluate the accuracy of periacetabular screw placement assessing pre-defined placement corridors and comparing different fluoroscopy-based navigation procedures and the conventional technique.For each screw an individual periacetabular placement corridor was preoperatively planned using the planning software iPlan CMF© 3.0 (BrainLAB). 210 screws (retrograde anterior column screws, retrograde posterior column screws, supraacetabular ilium screws) were placed in an artificial Synbone pelvis model (30 hemipelves) and in human cadaver specimen (30 hemipelves). 2D- and 3D-fluoroscopy-based navigation procedures were compared to the conventional technique. Insertion time and radiation exposure to specimen were also recorded. The achieved screw position was postoperatively assessed by an Iso-C3D scan. Perforations of bony cortices or articular surfaces were analysed and the screw deviation severity (difference of the operatively achieved screw position and the preoperatively planned screw position in reference to the pre-defined corridors) was determined using image fusion.Using 3D-fluoroscopy-based navigation, the screw perforation rate (7%) was significantly lower compared to 2D-fluoroscopy-based navigation (20%). For all screws, the deviation severity was significantly lower using a 3D- compared to a 2D-fluoroscopy-based navigation and the conventional technique. Analysing the posterior column screws, the screw deviation severity was significantly lower using 3D- compared to 2D-fluoroscopy-based navigation. However, for the anterior column screw, the screw deviation severity was similar regardless of the imaging method. Despite the advantages of the 3D-fluoroscopy-based navigation, this method led to significantly longer total procedure and fluoroscopic times, and the applied radiation dose was significantly higher.Percutaneous periacetabular screw placement is demanding. Especially for posterior column screws, due to a lower perforation rate and a higher accuracy in periacetabular screw placement, 3D-fluoroscopy-based navigation procedure appears to be the method of choice for image guidance in acetabular surgery.

Effect of Radiation Sterilization on Alprenolol in the Solid State Studied by High-Performance Thin-Layer Chromatography

The possibility of radiation sterilization of alprenolol (AL) has been studied. Irradiation of AL in solid form with a 25 kGy beam of electrons caused only an insignificant change in color that became more intense with increasing irradiation dose. Moreover, with increasing dose a decrease in pH, the content of water, and the degree of crystallinity were observed. AL in solid form was radiated with a high-energy electron beam (9.96 MeV) at doses from 25-400 kGy and analyzed by HPTLC using the mobile phase methanol-ammonia 25% (99 + 1, v/v). Densitometric analysis was carried out directly from chromatograms at 270 nm. The applied method was validated and characterized by good precision (RSD = 3.95%); good accuracy (80% level 100.15%, 100% level 99.99%, and 120% level 104.44%); and low LOD (LOD = 0.52 microg/zone and LOQ = 1.55 microg/zone). Chromatograms recorded for samples irradiated at the doses of 25 kGy were unchanged, but at higher doses (100-400 kGy) additional peaks corresponding to the radiodegradation products appeared (Rf = 0.24 and Rf = 0.40). The decrease in the concentration of AL was proportional to the applied radiation dose, and for 400 kGy the concentration of AL was 90.23%. The calculated radiolytic yield of the radiodegradation process was G(-AL) = 7.12 x 10(-7) mol/J.

Usability of tartaric acid in dose measurements: an ESR study

Unirradiated tartaric acid samples do not exhibit any ESR signal. However, the ESR spectra of irradiated samples contain many resonance signals. The dose–responce curves of the resonance signals, denoted as I 1, I 2, I 3 and I 4 in the present study, were found to increase linearly with the applied radiation dose in the range of 0.04–25 kGy. Adjusting the microvawe power and modulation amplitudes of 1.0 mW and 1.0 mT, respectively, was found to increase the sensitivity of tartaric acid. From the dose–response curves and room temperature decay data, it was concluded that the I 3 resonance signal of tartaric acid can be used for dose measurements at intermediate (0.04–0.4 kGy) and high dose (0.5–25 kGy) levels.

The effects of temperature on ESR spectrum of gamma-irradiated ammonium tartrate

Unirradiated ammonium tartrate (AT) samples do not exhibit any ESR signal. However, irradiation produces an unresolved singlet at g=2.0034±0.0006 with two shoulders at g 1=2.0093±0.0006 and g 2=2.0048±0.0006. The dose–response curve was found to increase linearly with the applied radiation doses in the range of 0.1–2.0 kGy and the slope of this curve was increased as the modulation amplitude increased. The activation energy value E a=69.0±1.2 kJ/mol was calculated from Arrhenius plot for the radical species responsible from ESR spectrum of irradiated AT.

Effects of the ionizing radiations, freezing and thawing duration on chicken liver cells quality

All food storage processes modify the food. Irradiation reduces and could stop cell division, avoid infestation, reduce contamination and delay food decomposition. The cold chain is a succession of steps which maintains the food at low temperature. Defrosted food shall never be frozen again, the best way being to consume it quickly then avoiding multiplication and acceleration of microbial growth, which causes decay and nutrients damage. The Comet Assay indicates DNA damage and can then be used to control the overall quality of the food and in a certain extent to evaluate the damage caused by irradiation and storage on liver chicken cells. In this work, different thawing temperatures and radiation doses were checked to establish a “DNA damage index” by using the Comet Assay. Samples were irradiated in a 60Co irradiator with 1.5, 3.0 and 4.5 kGy radiation doses. Our results showed that no intact cells were detected in frozen samples: however, irradiated liver samples in natura showed some intact cells depending on the applied radiation doses.

Effects of gamma radiation on microbiological status, fatty acid composition, and color of vacuum-packaged cold-stored fresh pork meat.

Pork meat samples were inoculated with high or low levels (10(6) or 10(3) CFU/g) of Salmonella Enteritidis, vacuum packaged, exposed to gamma radiation (1.0, 2.5, and 4.7 kGy), and stored for 1 month at 4 +/- 1 degrees C. In highly contaminated samples, the target strain was completely eliminated only by the 4.7 kGy radiation dose, whereas in samples at the lower contamination level, 2.5 kGy was sufficient to eliminate Salmonella Enteritidis. The highest of the applied radiation doses reduced the aerobic microflora and extended the sample's refrigeration shelf life by at least 2 weeks. The fatty acid profile of pork meat was not significantly affected by any of the applied radiation doses. Irradiation increased the proportion of saturated fatty acids (SFA) and decreased the content of the polyunsaturated fatty acids (P < 0.05). Irradiation also affected negatively the proportions of the nutritional indexes omega-6/omega-3, SFA/monounsaturated fatty acids, and SFA/polyunsaturated fatty acids. The proportion of the trans fatty acids C18:1omega-9 t9 and C18:2 t9,t12 in the total fatty acids was nearly doubled (90 and 86%, respectively) in the samples that had been exposed to 4.7 kGy. None of the applied radiation doses changed the lightness (L* value) of the meat, but redness (a*) and yellowness (b*) increased, particularly for the samples treated with 4.7 kGy.

Patient radiation dose during percutaneous interventional closure of interatrial communications

To determine fluoroscopy time (FT) and radiation dose (RD) applied in percutaneous closure of interatrial septal communications (IAC). Percutaneous closure of IAC, namely patent foramen ovale (PFO) and atrial septal defect (ASD) is increasingly performed. In this often young population in full reproductive age, radiation dosage should be an important issue, yet consistent data on applied radiation dose have not been available to date. A single center observational cohort study in 50 consecutive patients undergoing closure of a PFO or ASD. RD and FT as recorded by the cardiac catheter laboratory were determined to be the main outcome measures. Secondary outcome measures were determined to be major adverse events. FT averaged 6.3 (+/-4, 1.4-21.1) min, whereas RD measured as dose area product averaged 325.5 (+/-271.1; 11.6-1103.4) dGray x cm(2). The latter is equivalent to an effective dose of 6.5 milliSievert (0.24-22 mSv). Whereas closure of IAC can be associated with a low radiation exposure of 0.24 mSv, sometimes appreciably higher doses are applied, mandating more careful consideration of radiation safety issues in this patient population, especially the subset younger than 45 years. Analogous to data and recommendations published for radiation dose in coronary angiography, there is a need for binding reference values which would serve as guidelines for closure of IAC.

From the Editors

<i>From the Editors</i>

Effects of γ radiation on fiber‐reinforced polymer concrete

AbstractComposites were made from 30% unsaturated polyester resin + 70% calcium bentonite and marble as aggregates, as well as 0.3 and 0.4 vol% of nylon fibers. The fiber‐containing polymer concretes (PCs) were subjected to 5, 10, 50, and 100 kGy applied radiation doses. The compressive strength values depend on both the fiber concentration and the irradiation dose applied. Moreover, the polyester‐based PCs containing two mineral aggregates, calcium carbonate and marble, have lower compressive strength values than those reported earlier for PCs containing only either silica sand or CaCO3. However, significant improvement of the compressive strain and the compression modulus of elasticity are achieved when nylon fibers are added. Both these properties go symbatically with the radiation dose. Mechanical characteristics can be related to the morphological features observed by scanning electron microscopy. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Compressive strength of gamma‐irradiated polymer concrete

AbstractPolymer concrete (PC) was developed by using different concentrations of silica sand as aggregate and a commercial unsaturated preaccelerated (orthophtalic) polyester resin. The PC specimens were submitted to gamma radiation at several dosages: 5, 10, 50, 100, and 150 kGy. Mechanical performance was evaluated including the compressive strength, the compressive strain at yield point, and the compression modulus of elasticity. As expected, mechanical properties depend on both the resin concentration and the applied radiation dose. Improvement achieved in mechanical properties is related to the morphological characteristics observed by scanning electron microscopy. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Quality Control of Involved Field Radiotherapy in Patients With Early-Favorable (HD10) and Early-Unfavorable (HD11) Hodgkin's Lymphoma: An Analysis of the German Hodgkin Study Group

The German Hodgkin Study Group (GHSG) set up a radiotherapy (RT) reference center within the Department of Radiation Oncology at the University of Cologne to undertake quality assurance of the group's clinical studies. In the HD10 trial (early-favorable stages) and HD11 trial (early-unfavorable stages) all patients received involved field (IF)-RT (30 Gy vs. 20 Gy) within a combined-modality approach. For these patients a central prospective review of all diagnostic imaging was performed by expert radiation oncologists to control disease extension and to define IF treatment volume. On the basis of simulation films, verification films, and radiotherapy case report form (CRF) an expert panel evaluated retrospectively the adequacy of irradiated IF treatment portals according to the RT prescription, applied radiation doses, treatment time, and technical parameters. Between 1999 and 2006 a total of 825 of 1370 randomized patients of the HD10 trial (60%) and 954 of 1422 patients of the HD11 trial (67%) were evaluated by the panel. Radiotherapy was rated as suboptimal in 47% of all reviewed cases. Although the participating RT centers received a precise RT prescription, most difficulties occurred in the adequate coverage of the IF (40%), followed by technical faults (12%). Deviations from the prescribed single daily dose (1.8-2 Gy), weekly dose, and total reference dose were rare (1%). As a consequence of these findings, radiation oncologists were trained on the definition of IF-RT at GHSG meetings and at the annual meetings of the German Society for Therapeutic Radiation Oncology. Possible correlations between RT quality and relapse rate will be investigated.

Radiosensitivities of creatine and creatinine: an ESR study

In this work, radiosensitivies of solid creatine (C1) and its dehydrated form creatinine (C2) were studied by electron spin resonance (ESR) spectroscopy after irradiating them at room temperature by gamma rays. Although unirradiated C1 and C2 exhibited no ESR signal, irradiated C1 and C2 presented ESR spectra of unresolved triplet and doublet appearances, respectively. Variations of the intensities associated with the triplet and doublet spectra with microwave power, temperature, storage time at room temperature, and applied radiation dose were investigated. Three radical species with different decay features were calculated to govern the biphasic decays of the intensities associated with three assigned resonance peaks of C1. Intensities related with two resonance peaks of unresolved doublet of C2 were found to stay almost constant at room temperature over a storage period of about 2 months and vary similarly with the increase in microwave power and applied radiation dose. This was evaluated by implying the presence of single type radicals giving rise to the formation of the observed doublet signal of C2. Radiation yields of C1 and C2 were calculated to fall into the range of most materials.