Long-pulsed 1064-nm and 755-nm lasers for C1 leg veins on skin type IV patients: a side-by-side comparison.

Long-pulsed 1064-nm (LP1064) and 755-nm (LP755) lasers have been demonstrated as effective treatments for leg veins. However, few studies of these treatments on Asian skin type as well as direct comparison between two methods were reported. The aim of this study was to compare the clinical efficacy and safety of LP1064 with LP755 in the treatment of C1 leg veins on skin type IV patients. Patients with symmetric matched areas C1 leg veins were treated with single session of LP1064 for the right and LP755 for the left. Treated areas of every patient were divided into matrices of 2 × 2 cm squares. Vessels in the highest density squares were subjected to evaluation. Spot sizes were 5 mm fixed. Pulse durations and fluences were according to vessel diameters and endpoints, respectively. The clearances were evaluated at 1 and 3 months post treatment. Side effects were recorded immediately, 10 min, 24 h, and 1 and 3 months after treatment. Twenty-two patients were enrolled with total 96 vessels from 22 selected squares in the right and 106 vessels from 22 selected squares in the left. At 1-month follow-up, the clearances of LP1064 and LP755 were not significantly different (71.87% and 71.69%, respectively; p = 0.99). At 3-month follow-up, the efficacies were constant and no recurrence occurred. Pain levels of both methods were moderate and significantly lower in LP755. These findings suggest that LP1064 and LP755 laser treatments were comparatively effective and safe for C1 leg veins of skin type IV patients.

Body Anatomical UV Protection Predicted by Shade Structures: A Modeling Study.

Shade is an important means of protection against harmful effects of sun ultraviolet (UV) exposure, but not all shades are identically protective. UV rays scattered by the atmosphere and surroundings can reach the skin indirectly. To evaluate the relative contribution of the direct, diffuse, and reflected radiation in UV protection provided by different sizes of shade structure, we used SimUVEx v2, a numeric tool based on 3D graphic techniques and ambient ground UV irradiance. The relative UV exposure reduction was expressed by the predictive protection factor (PPF). Shade structures were found to predominantly reduce exposure from direct radiation (from 97.1% to 99.9% for the upper body areas such as the head and the neck), with greater protection from larger shade structures and structures closer above the subject. Legs were the least protected anatomical zone from any shade structure above the subject with PPF ranging from 18.5% to 68.1%. Throughout the day, except for lower solar zenith angles (SZA), small and high shade structures provide the lowest protection (between 20% and 50%), while small and low shade structure show PPF between 35% and 65% and large and high shade structures reach PPF higher than 60%.

Physician assessed and patient reported lower limb edema after definitive radio(chemo)therapy and image-guided adaptive brachytherapy for locally advanced cervical cancer: A report from the EMBRACE study.

BACKGROUND/PURPOSE: To evaluate the pattern of manifestation and risk factors for lower limb edema (LLE) within the prospective, observational, multi-center EMBRACE study on radiochemotherapy and MRI-guided brachytherapy in locally advanced cervical cancer (LACC). MATERIAL/METHODS: LLE was prospectively assessed according to the physician-reported CTCAE v.3 and patient-reported EORTC QLQ-CX24 questionnaire at baseline and regular follow-up. RESULTS: In total, 1176 patients were evaluated with a median follow-up of 27 months. Actuarial analyses revealed 3/5-year estimates of 27%/31% of CTCAE G ≥ 1, 6.1%/6.6% of G ≥ 2 and 0.5%/0.5% for G ≥ 3. Prevalence rates for G ≥ 1 LLE at 3 months, 1, 3 and 5 years after end of treatment were 7%, 12%, 12%, 15% for physician-assessed and 25%, 30%, 30%, 34% for any patient-reported symptoms and showed a steady increase over time. Invasive lymph node staging and obesity at diagnosis are independent significant risk factors for G ≥ 1 LLE, whereas nodal boost has no impact. Extended radiation fields including para-aortic and/or inguinal nodes show a tendency to increase the risk. CONCLUSION: Severe LLE after definitive radiochemotherapy in LACC is rare. However, the risk for mild LLE is considerable, and related to patient-, diagnostic- and treatment characteristics. Less invasive diagnostic surgical procedures or non-invasive assessment, less invasive radiotherapy management and active rehabilitation are important pathways for future developments.

Dose-response effect of photobiomodulation therapy on neuromuscular economy during submaximal running.

The purpose of this study was to verify the photobiomodulation therapy (PBMT) effects with different doses on neuromuscular economy during submaximal running tests. Eighteen male recreational runners participate in a randomized, double-blind, and placebo-controlled trial, which each participant was submitted to the same testing protocol in five conditions: control, placebo, and PBMT with doses of 15, 30, and 60 J per site (14 sites in each lower limb). The submaximal running was performed at 8 and 9 km h-1 during 5 min for each velocity. Muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), and gastrocnemius lateralis (GL) was collected during the last minute of each running test. The root mean square (RMS) was normalized by maximal isometric voluntary contraction (MIVC) performed a priori in an isokinetic dynamometer. The RMS sum of all muscles (RMSLEG) was considered as main neuromuscular economy parameter. PBMT with doses of 15, 30, and 60 J per site [33 diodes = 5 lasers (850 nm), 12 LEDs (670 nm), 8 LEDs (880 nm), and 8 LEDs (950 nm)] or placebo applications occurred before running tests. For the statistical analysis, the effect size was calculated. Moreover, a qualitative inference was used to determine the magnitude of differences between groups. Peak torque and RMS during MIVCs showed small effect sizes. According to magnitude-based inference, PBMT with dose of 15 J per site showed possibly and likely beneficial effects on neuromuscular economy during running at 8 and 9 km h-1, respectively. On other hand, PBMT with doses of 30 and 60 J per site showed possible beneficial effects only during running at 9 km h-1. We concluded that PBMT improve neuromuscular economy and the best PBMT dose was 15 J per site (total dose of 420 J).

Radiation-Induced DNA Damage in Operators Performing Endovascular Aortic Repair.

BACKGROUND: Radiation exposure during fluoroscopically guided interventions such as endovascular aortic repair (EVAR) is a growing concern for operators. This study aimed to measure DNA damage/repair markers in operators perfoming EVAR. METHODS: Expression of the DNA damage/repair marker, γ-H2AX and DNA damage response marker, phosphorylated ataxia telangiectasia mutated (pATM), were quantified in circulating lymphocytes in operators during the peri-operative period of endovascular (infrarenal, branched, and fenestrated) and open aortic repair using flow cytometry. These markers were separately measured in the same operators but this time wearing leg lead shielding in addition to upper body protection and compared with those operating with unprotected legs. Susceptibility to radiation damage was determined by irradiating operators' blood in vitro. RESULTS: γ-H2AX and pATM levels increased significantly in operators immediately after branched endovascular aortic repair/fenestrated endovascular aortic repair (P<0.0003 for both). Only pATM levels increased after infrarenal endovascular aortic repair (P<0.04). Expression of both markers fell to baseline in operators after 24 hours (P<0.003 for both). There was no change in γ-H2AX or pATM expression after open repair. Leg protection abrogated γ-H2AX and pATM response after branched endovascular aortic repair/fenestrated endovascular aortic repair. The expression of γ-H2AX varied significantly when operators' blood was exposed to the same radiation dose in vitro (P<0.0001). CONCLUSIONS: This is the first study to detect an acute DNA damage response in operators performing fluoroscopically guided aortic procedures and highlights the protective effect of leg shielding. Defining the relationship between this response and cancer risk may better inform safe levels of chronic low-dose radiation exposure.

An end-to-end assessment of range uncertainty in proton therapy using animal tissues.

Accurate assessment of range uncertainty is critical in proton therapy. However, there is a lack of data and consensus on how to evaluate the appropriate amount of uncertainty. The purpose of this study is to quantify the range uncertainty in various treatment conditions in proton therapy, using transmission measurements through various animal tissues. Animal tissues, including a pig head, beef steak, and lamb leg, were used in this study. For each tissue, an end-to-end test closely imitating patient treatments was performed. This included CT scan simulation, treatment planning, image-guided alignment, and beam delivery. Radio-chromic films were placed at various depths in the distal dose falloff region to measure depth dose. Comparisons between measured and calculated doses were used to evaluate range differences. The dose difference at the distal falloff between measurement and calculation depends on tissue type and treatment conditions. The estimated range difference was up to 5, 6 and 4 mm for the pig head, beef steak, and lamb leg irradiation, respectively. Our study shows that the TPS was able to calculate proton range within about 1.5% plus 1.5 mm. Accurate assessment of range uncertainty in treatment planning would allow better optimization of proton beam treatment, thus fully achieving proton beams' superior dose advantage over conventional photon-based radiation therapy.

A MONTE CARLO STUDY OF SIMULATED MEASUREMENTS OF RADIONUCLIDES IN BONE.

When measuring the internally deposited activity in the bone of a subject, the placement of the detector is critical. This study reports the simulated counting efficiencies for three counting geometries, the skull, knee and shin, using 13 different voxel phantoms. It shows that the range of counting efficiencies for a given geometry is large for the studied phantoms, especially at low energies. Skull counting offers higher efficiency for low energies such as the 17 keV compared to knee counting or shin counting, but this advantage disappears when the energy is higher such as at 185 keV. This work also shows that the calibration phantom may greatly impact the accuracy of the activity estimate in bone counting, with uncertainties increasing greatly as the photon energy is reduced. Estimating the activity of a radionuclide in bone from direct counting has large uncertainties, and the dose calculated from a skeleton measurement would need careful analysis and, if possible, supporting data from other bioassay measurements.

Leg heating using far infra-red radiation in patients with chronic heart failure acutely improves the hemodynamics, vascular endothelial function, and oxidative stress.

BACKGROUND: Systemic thermal therapy (STT) has been associated with beneficial effects in patients with chronic heart failure (CHF). The fact, however, that it requires a dedicated as well as spacious facility and trained personnel makes it difficult to practice in the daily care of patients with CHF. OBJECTIVE: The aim of this study was to determine whether the leg thermal therapy (LTT) has a positive impact similar to that of STT in patients with CHF. Methods and Results Twenty patients with CHF (57 ± 17 years old, left ventricular ejection fraction=30 ± 10%) received LTT (45°C) for 20 minutes. Immediately after the treatment, the core temperature had increased (+0.3 ± 0.3°C) (p<0.01). While the LTT had no significant effects on the heart rate, systolic arterial pressure, and diastolic blood pressure, it increased the cardiac output (mixed venous oxygen saturation; +2 ± 3%) and decrease the pulmonary capillary wedge pressure (-2 ± 2 mmHg). The LTT significantly improved the flow-mediated vasodilatation (FMD) from 4.8 ± 2.6 to 7.1 ± 3.6%, the antioxidative markers, thiol from 4.0 ± 0.7 to 4.5 ± 0.9 µmoL/g, and the marker of oxidative deoxyribonucleic acid (DNA) damage, urine 8-hydroxy-2'deoxyguanosine (8OHdG) from 100 to 82 ± 3%, respectively (p<0.05). No patient had any adverse effects associated with LTT. Conclusion LTT acutely improved FMD, and oxidative stress in patients with CHF. Although the long-term effect of LTT remains to be investigated, its practicality which is comparable to that of STT would make it an attractive therapeutic strategy for patients with CHF.

Radiation exposure of the operator during cardiac catheter ablation procedures.

Radiation exposure of the operator during cardiac catheter ablation procedures was assessed for an experienced cardiologist adopting various measures of radiation protection and utilised electroanatomic navigation. Chip thermoluminescent dosemeters were placed at the eyes, chest, wrists and legs of the operator. The ranges of fluoroscopy time and air kerma area product values associated with cardiac ablation procedures were wide (6.3-48.3 min and 1.7-80.3 Gy cm(2), respectively). The measured median radiation doses per procedure for each monitored position were 23.6 and 21.3 µSv to the left and right wrists, respectively, 25.3 and 30.4 µSv to the left and right legs, respectively. The doses to the eyes were below the minimum detectable dose of 9 µSv. The estimated median effective dose was 22.5 µSv. Considering the actual workload of the operator, the calculated annual doses to the hands, legs and eyes, as well as the annual effective dose, were all below the corresponding limits. The findings of this study indicate that cardiac ablation procedures performed at a modern laboratory do not impose a high radiation hazard to the operator when radiation protection measures are routinely adopted.

Bone density changes after radiation for extremity sarcomas: exploring the etiology of pathologic fractures.

PURPOSE: The incidental irradiation (RT) of adjacent bone that takes place during treatment of soft tissue extremity sarcomas is generally presumed to "weaken" the bone by decreasing its density, which subsequently increases the risk for pathologic fracture. This investigation intended to assess the relative effects on bone density of both RT and diminished mechanical loading secondary to tumor-induced and therapy-induced functional extremity impairment. METHODS AND MATERIALS: 19 patients treated with surgical excision and RT for soft tissue extremity sarcomas had bone density measured using dual energy X-ray absorptiometry at four sites: the irradiated (A) and contralateral (B) bone, and an uninvolved bone (C) in the treated extremity and its contralateral counterpart (D). Analysis included (1) [A-B], (2) [C-D], (3) [(A-B), - (C-D)], and (4) [(A-B)/B - (C-D)/D]. RESULTS: The mean bone density for all irradiated sites was increased 0.08 ± 0.22 g/cm(2) (variance) compared to the contralateral unirradiated side when corrected for weight-bearing effects (3). An average increase in bone density of 9 ± 22% (p = 0.08) was also seen when the differences were divided by individual control densities to normalize variation in density of different anatomic sites (4). CONCLUSIONS: RT does not routinely decrease bone density when corrected for weight bearing or mechanical effects. The pathogenesis for the known increased risk of pathologic fracture in irradiated bones is likely multifactorial, including possible alterations in bone remodeling that can result in stable, or even increased, bone density. Further clinical and basic studies are needed to confirm our unexpected findings.

Numerical dosimetric reconstruction of a radiological accident in South America in April 2009.

A severe irradiation accident involving a victim occurred in April 2009 in South America. The victim has found a (192)Ir source fallen from a gammagraphy device and has put it in the left pocket of his pants. Very quickly, an erythema and a blister appeared on the left leg of the victim involving hospitalisation. Following the request of the IAEA assistance, the Ionizing Radiation Dosimetry Laboratory of IRSN was asked to perform a numerical dosimetric reconstruction. A personalised voxel phantom of the victim has been constructed thanks to the Simulation of External Source Accident with Medical images tool developed by the laboratory, and a calculation of the dose with the MCNPX computer code allowed to determine the boundary of the necrotic dose at 25 Gy. On the basis of these calculations, the physicians have performed exeresis of the necrotic region on the left leg on 4 May 2009. Associated with mesenchymal stem cell injection, the leg of the victim was healthy on December 2009.

Personal dosimetry for interventional operators: when and how should monitoring be done?

OBJECTIVE: Assessment of the potential doses to the hands and eyes for interventional radiologists and cardiologists can be difficult. A review of studies of doses to interventional operators reported in the literature has been undertaken. METHODS: Distributions for staff dose to relevant parts of the body per unit dose-area product and for doses per procedure in cardiology have been analysed and mean, median and quartile values derived. The possibility of using these data to provide guidance for estimation of likely dose levels is considered. RESULTS: Dose indicator values that could be used to predict orders of magnitude of doses to the eye, thyroid and hands from interventional operator workloads have been derived, based on the third quartile values, from the distributions of dose results analysed. CONCLUSION: Dose estimates made in this way could be employed in risk assessments when reviewing protection and monitoring requirements. Data on the protection provided by different shielding and technique factors have also been reviewed to provide information for risk assessments. Recommendations on the positions in which dosemeters are worn should also be included in risk assessments, as dose measurements from suboptimal dosemeter use can be misleading.

Measurements of the anatomical distribution of erythemal ultraviolet: a study comparing exposure distribution to the site incidence of solar keratoses, basal cell carcinoma and squamous cell carcinoma.

Measurements of anatomical UV exposure distribution were made using miniaturized polysulfone dosimeters over a four year period between 2005 and 2008 in Toowoomba, Australia (28 degrees S, 152 degrees E). Anatomical UV exposures were expressed relative to the horizontal plane ambient UV. The UV exposures were compared with existing data detailing the anatomical distribution of basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and solar keratoses (SK). Surface UV exposures to unprotected skin surfaces have been presented for each of the face, neck, arm, hand and leg assessing a total of 1453 body sites (2491 measurements). Measured exposures are presented for the human facial region to a resolution of 5 mm. The median anatomical UV expressed relative to the horizontal plane ambient UV for each of the face, neck, forearm, hand and leg regions of the body varied from 26%, 23%, 13%, 30% and 12% respectively in the 0 degrees-30 degrees SZA range; 39%, 36%, 17%, 35% and 23% in the 30 degrees-50 degrees SZA range; and 48%, 59%, 41%, 42% and 47% in the 50 degrees-80 degrees SZA range. Detailed positions of UV exposure measured over the face, neck, arm, hand and leg were more closely related to NMSC incidence data for the face and upper limbs. Further analysis with existing facial BCC and SK density data did not however show a direct relationship with the measured UV exposures highlighting the importance of other factors influencing the causation and localisation of facial NMSC.

Training software using virtual-reality technology and pre-calculated effective dose data.

This paper describes the development of a software package, called VR Dose Simulator, which aims to provide interactive radiation safety and ALARA training to radiation workers using virtual-reality (VR) simulations. Combined with a pre-calculated effective dose equivalent (EDE) database, a virtual radiation environment was constructed in VR authoring software, EON Studio, using 3-D models of a real nuclear power plant building. Models of avatars representing two workers were adopted with arms and legs of the avatar being controlled in the software to simulate walking and other postures. Collision detection algorithms were developed for various parts of the 3-D power plant building and avatars to confine the avatars to certain regions of the virtual environment. Ten different camera viewpoints were assigned to conveniently cover the entire virtual scenery in different viewing angles. A user can control the avatar to carry out radiological engineering tasks using two modes of avatar navigation. A user can also specify two types of radiation source: Cs and Co. The location of the avatar inside the virtual environment during the course of the avatar's movement is linked to the EDE database. The accumulative dose is calculated and displayed on the screen in real-time. Based on the final accumulated dose and the completion status of all virtual tasks, a score is given to evaluate the performance of the user. The paper concludes that VR-based simulation technologies are interactive and engaging, thus potentially useful in improving the quality of radiation safety training. The paper also summarizes several challenges: more streamlined data conversion, realistic avatar movement and posture, more intuitive implementation of the data communication between EON Studio and VB.NET, and more versatile utilization of EDE data such as a source near the body, etc., all of which needs to be addressed in future efforts to develop this type of software.

gamma-H2AX foci formation in peripheral blood lymphocytes of tumor patients after local radiotherapy to different sites of the body: dependence on the dose-distribution, irradiated site and time from start of treatment.

PURPOSE: To evaluate the relationship between an estimated integral total body radiation dose delivered and phosphorylated histone H2AX protein (gamma-H2AX) foci formation in peripheral blood lymphocytes of cancer patients. MATERIAL AND METHODS: gamma-H2AX formation was quantified as the mean number of foci per lymphocyte (N(meanH2AX)) and the percentage of lymphocytes with > or =n foci. The integrated total body radiation dose was estimated from the dose volume histogram of patient's body corrected for the proportion of the body scanned by computed tomography for 3D treatment planning. RESULTS: There was a strong linear correlation between the mean number of gamma-H2AX foci per lymphocyte in the peripheral blood sample and integrated total body radiation dose (r = 0.83, p < 0.0001). The slope of the relationship was dependent on the site of body irradiated. In comparison to chest irradiation with a slope of 8.7 +/- 0.8 foci Gy(-1), the slopes for brain, upper leg and pelvic sites were significantly shallower by -4.7, -4.3, and -3.8 Gy(-1), respectively (p < 0.0001), while the slope for upper abdomen irradiation was significantly larger by 9.1 +/- 2.6 Gy(-1) (p = 0.0007). There was a slight time effect since the start of radiotherapy on the slopes of the in vivo dose responses leading to shallower slopes (-1.5 +/- 0.7 Gy(-1), p = 0.03) later (> or =10 day) during radiotherapy. After in vitro irradiation, lymphocytes showed 10.41 +/- 0.12 foci per Gy with no evidence of inter-individual heterogeneity. CONCLUSIONS: gamma-H2AX measurements in peripheral lymphocytes after local radiotherapy allow the estimation of the applied integral body dose. The site and time dependence have to be considered.

The use of extremity dosemeters in a hospital environment.

A general overview is given on the use of extremity dosemeters, their calibration, the units and phantoms to be used. One of the major applications of extremity dosemeters is to monitor the personnel in a hospital environment. In nuclear medicine, brachytherapy and interventional radiology (IR) skin doses to hands and legs can be substantial. Here, we report on two studies that are presently being undertaken in Belgium. The first one tries to map the dose distribution on the hands, in function of the manipulation in nuclear medicine. Some preliminary results are also given from a nationwide survey study for patient and personnel doses during IR and cardiology. The radiologists' hands, legs and forehead are monitored during a whole range of procedures in different hospitals.

TENS to the posterior aspect of the legs decreases postural sway during stance.

The purpose of this study was to examine the effect of Transcutaneous Electrical Nerve Stimulation (TENS) applied to the posterior aspect of the legs, on postural sway during stance. Thirty healthy subjects were tested while standing on a force platform under four stimulation conditions: no TENS, bilateral TENS, and unilateral left and right TENS. Thirty-second long tests, employing detection threshold amplitudes, were performed in three blocks. In each block, the four conditions were applied both with and without vision in a random order. The results indicate that the application of TENS brought about a decrease in postural sway as expressed by average sway velocity, in addition to a decrease in the absolute values of maximal and minimal medio-lateral and anterior-posterior velocity. Thus, similar to sub-threshold random electrical noise, it appears that the application of low-amplitude TENS to the lower limbs decreases postural sway during stance. Considering the ease of TENS application and the high prevalence of postural disorders, the potential clinical significance of this observation is to be determined by further studies.

Monte Carlo investigations of distance-dependent effects on energy deposition in K-shell x-ray fluorescence bone lead measurement.

Radiation energy deposition results are presented from a Monte Carlo code simulating the lower part of a leg during an in vivo 109Cd K-shell x-ray fluorescence (KXRF) bone lead measurement. The simulations were run for a leg phantom model representing an adult subject, assuming concentrations of 10 microg Pb per gram bone mineral and tracing 500 million photons in each simulation. Trials were performed over a range (0.5-6.0 cm) of source-to-sample (S-S) distances. Energies deposited due to Compton and photoelectric processes occurring in the bone and the soft tissue were obtained. The data show an increase in the amount of energy deposited in the bone as the sample is moved closer to the source (from 2.0 cm to 0.5 cm). However, there is a decrease in the amount of energy deposited in the soft tissue as the sample is moved closer to the source over the same distance interval. In decreasing the S-S distance from 2.0 cm to 0.5 cm, the amount of energy deposited in the sample as a whole was found to increase by 11%. By calculating the energy deposition in the bone and in the soft tissue as a fraction of the total energy deposited in the sample, the corresponding changes are quantified as a function of S-S distance. Similarly, the proportions of energy deposited via the photoelectric effect and Compton scattering are presented as a function of S-S distance.