The effect of low-volatile organic compounds, water-based paint on aggravation of allergic disease in schoolchildren.

Whether indoor painting aggravates preexisting allergic diseases remains unclear. We aimed to evaluate the impact of new classroom painting on aggravation of asthma, allergic rhinitis (AR), and atopic dermatitis (AD) in children. Studied school was previously painted with conventional water-based paint 20 years ago and had natural ventilation system. We identified a total of 172 children aged 10-12 years with allergic diseases in 17 classrooms, which were allocated to newly painted rooms with low-volatile organic compounds (VOC), water-based paint, or existing rooms. After painting, there was no intervention or internal airflow to influence indoor air environment in both classrooms. We prospectively assessed the symptom severity and serious events of allergic diseases between both classrooms at baseline and after one and eight weeks after painting. At one and eight weeks, there were no significant changes in the Childhood Asthma Control Test scores, the fractional nitric oxide levels, lung function in asthmatic children in either classroom. There were also no significant changes in the severity score of AR or AD, or serious events in all allergic diseases. These findings suggest classroom painting with this new paint at the levels encountered in this study might not be a major aggravating factor for school-aged children with allergic diseases.

Donor-Derived Strongyloidiasis Infection in Solid Organ Transplant Recipients: A Review and Pooled Analysis.

BACKGROUND: Donor-derived Strongyloides stercoralis infection in solid organ transplant (SOT) recipients is uncommon. Immunosuppressed SOT recipients are at risk of developing severe forms of strongyloidiasis infection through transmission from an infected donor allograft. METHODS: PubMed was searched for English-written articles published up to April 2015. Articles that reported cases of donor-derived strongyloidiasis infection in SOT recipients were reviewed for a pooled analysis. RESULTS: A total of 27 cases were identified from various SOT recipients. Donors were mostly from Strongyloides endemic regions (23 cases). No transplant recipients received prophylaxis against strongyloidiasis infection. Median age was 53 years. Median time of presenting symptoms after the solid organ transplantation was 72 days. The most common presenting symptoms were gastrointestinal (GI) symptoms (19 cases; 70.4%). Diagnosis of strongyloidiasis infection was mainly made by the confirmation of Strongyloides larvae or worm in GI samples (19 cases) and respiratory samples (14 cases). Donor-derived strongyloidiasis infection was evidenced by serology test results in 17 cases and epidemiological risk assessment analysis in 10 cases. Ivermectin was the most commonly used medication with use of a combination of iverrmectin and albendazole or thiabendazole in 15 cases. Death was noted in 9 cases (34.6%) of 26 cases with known outcomes. Presence of sepsis or bacteremia was a predictor of mortality because it was seen in 9 patients who died (100.0%) and in 4 patients who survived (23.5%; P < .001). CONCLUSIONS: Donor-derived strongyloidiasis infection in SOT recipients has high mortality. Effective donor screening and prophylaxis in high-risk SOT recipients may help to decrease morbidity and mortality associated with donor-derived strongyloidiasis.

Measurement of levels of fractional exhaled nitric oxide in patients with pulmonary tuberculosis.

SETTING: The role of fractional exhaled nitric oxide (FeNO) in the diagnosis and treatment of pulmonary tuberculosis (PTB) is uncertain. OBJECTIVE: To examine the value of FeNO as a biomarker for PTB. DESIGN: Baseline FeNO levels were compared in 69 PTB patients and 118 healthy controls. The correlation between baseline FeNO levels and clinical variables of tuberculosis were studied. FeNO levels were checked twice in the PTB group, at diagnosis and after 2 months of anti-tuberculosis medication, and factors affecting changes in FeNO levels after treatment were analysed. RESULTS: FeNO levels were not significantly different in the PTB group and controls (mean ± standard deviation 27.7 ± 17.6 parts per billion [ppb] vs. 27.0 ± 10.8 ppb, P = 0.531). In a multivariate regression analysis, no variable was shown to affect FeNO levels at diagnosis. FeNO levels did not significantly change after 2 months of treatment (26.8 ± 18.3 ppb vs. 24.0 ± 10.7 ppb, P = 0.257). Only PTB with a high FeNO level (>25 ppb) was related to a decline in FeNO levels after 2 months of treatment. CONCLUSION: FeNO levels do not appear to be affected in PTB patients.

Ipsapirone, a 5-HT1A agonist, suppresses REM sleep equally in unmedicated depressed patients and normal controls.

To determine whether ipsapirone, a 5-HT1A agonist, differentially suppresses REM sleep in depressed patients compared with normal controls, we administered placebo, ipsapirone 10 mg, or ipsapirone 20 mg in a double-blind, random order before bedtime in 18 unmedicated patients with depression and 16 age-matched, gender-matched normal controls. Compared to placebo, ipsapirone affected REM sleep measures equally in depressed patients and controls as follows: (1) increased REM latency; (2) reduced total REM percent, REM time, and REM density; and (3) delayed the onset of REM sleep. In addition, ipsapirone had similar effects in patients and controls in other sleep measures: (1) reduced total sleep time; (2) delayed sleep onset time; and (3) increased sleep latency, stage 1%, stage 2%, the amount of stage 3 & 4 sleep in the first non-REM period, and wake time after sleep onset. The study does not support the hypothesis that downregulated 5-HT1A receptors mediate the pathophysiology or sleep disturbances of depression, although further studies are needed as these patients did not differ from controls in baseline sleep measures.

A method for delivering accurate and uniform radiation dosages to the head and neck with asymmetric collimators and a single isocenter.

PURPOSE: To investigate the use of asymmetric collimators and a single isocenter for delivering a uniform, accurate dose of radiation to the head, neck, and supraclavicular lymph nodes. METHODS AND MATERIALS: A linear accelerator with a pair of asymmetric collimators is required for this technique. An isocenter was placed at the junction of the lateral head and neck fields and the anterior supraclavicular field. The asymmetric collimators were set longitudinally, by collimator rotation if necessary. The collimators split the radiation beam to all portals. Dose uniformity was measured at the junction with films in solid-water phantoms. RESULTS: Film dosimetry showed a uniform dose at the junction without hot or cold regions. A digital display tolerance of +/- 1.0 mm for a field size maintained an acceptable uniform dose (+/- 5% dose variation) at the junction. The single isocenter and asymmetric collimators reduced field setup time by half. No table rotation was required to match fields. CONCLUSION: The asymmetric collimators lead to easy and accurate patient setup. The absence of the trapezoid effect resulted in the complete coverage of the submandibular and cervical nodes without any hot spots.

A mobile shield to reduce scatter radiation to the contralateral breast during radiotherapy for breast cancer: preclinical results.

PURPOSE: To design a practical breast shield and to investigate its efficacy in reducing scattered radiation to the contralateral breast of patients undergoing radiation therapy for breast cancer. METHODS AND MATERIALS: We constructed a mobile shield consisting of (a) a mobile base and a counterweight; (b) a vertical column adjustable in height and a diagonal arm adjustable in angle; (c) a curved, 2.5-cm thick lead sheet with a 1-cm thick polystyrene liner for blocking scattered radiation; and (d) diode detectors to verify that the edge of the lead sheet is not in the useful beam in addition to the use of the field light. Measurements were performed with thermoluminescent dosimeters on 10 patients without the shield and on an anthropomorphic phantom with a pair of wax breasts with and without the shield. All of the patients were treated with 6-MV photons (Varian 6/100). The scattered radiation from the medial and lateral fields was measured separately. RESULTS: The contribution of the medial field to the total scattered dose was 70% to 75%, whether a medial wedge was used or not. However, without a medial wedge, the scattered dose was reduced by nearly 33% at 3 to 9 cm away from the medial border. In the anthropomorphic phantom study with wax breast, the mobile shield reduced the medial field contribution to the total scatter dose to less than the contribution from the lateral field without a shield. With a prescribed dose of 50 Gy and a medial wedge, the median scatter dose to the contralateral breast from 6 patients was 5.3 Gy; without a medial wedge, it was 3.8 Gy from 4 patients at 6 cm from the medial border. In the phantom study, with the shield the total dose to the contralateral breast was 1.0 Gy at 6 cm from the medial border with a same prescribed dose. CONCLUSION: The mobile shield reduced the scatter dose to the contralateral breast from the linear accelerator (Varian 6/100, 6-MV photons) by a factor of 3 to 4. The shield greatly reduced the scattered dose in the wax phantom. Equivalent reductions in patients may be clinically significant by reducing the risk of radiation-induced breast cancer in the contralateral breast of woman undergoing radiation therapy for breast cancer. The shield is safe and easy to adjust to each patient.

Differential dosing of prostate and seminal vesicles using dynamic multileaf collimation.

PURPOSE: We have investigated the potential of applying different doses to the prostate (PTV2) and prostate/seminal vesicles (PTV1) using multileaf collimation (MLC) for intensity modulated radiation therapy (IMRT). Current dose-escalation studies call for treatment of the PTV1 to 54 Gy in 27 fractions followed by 20 Gy minimum to the PTV2. A daily minimum PTV dose of 2 Gy using a 7-field technique (4 obliques, opposed laterals, and an ant-post field) is delivered. This requires monitor unit calculations, paper and electronic chart entry, and quality assurance for a total of 14 fields. The goal of MLC IMRT is to improve efficiency and deliver superior dose distributions. Acceptance testing and commissioning of the dynamic MLC (DMLC) option on a dual-energy accelerator was accomplished. Most of the testing was performed using segmental MLC (SMLC) IMRT with stop-and-shoot sequences built within the dynamic mode of the DMLC. METHODS AND MATERIALS: The MLC IMRT fields were forward planned using a three-dimensional treatment planning system. The 14 fields were condensed to 7 SMLC IMRT fields with two segments each. In this process, steps were created by moving the leaves to the reduced field positions. No dose (<0.01%) was delivered during this motion. The monitor units were proportioned according to the planned treatment weights. Film and ionization chamber dosimetry were used to analyze leaf positional accuracy and speed, output, and depth-dose characteristics. A geometric phantom was used for absolute and relative measurements. We obtained a volumetric computerized tomography (CT) scan of the phantom, performed 3D planning, and then delivered a single treatment fraction. RESULTS: The acceptance testing and commissioning demonstrated that the leaves move to programmed positions accurately and in a timely manner. We did find an approximately 1 mm offset of the set leaf position and radiation edge (50%) due to the curved-end nature and calibration limitations. The 7-field SMLC IMRT treatment duplicated the 14-field static plan dose distribution with variations no greater than 1.5%. CONCLUSIONS: The MLC IMRT approach will improve efficiency because the number of electronic and chart entries has decreased by a factor of 2. Portal images are able to capture the initial and final MLC segments. The question of differential daily dose to the prostate and seminal vesicles remains.

Three-dimensional conformal pancreas treatment: comparison of four- to six-field techniques.

PURPOSE: We compare practical conformal treatment approaches to pancreatic cancer using 6 and 18 MV photons and contrast those approaches against standard techniques. METHODS AND MATERIALS: A four-field conformal technique for treating pancreas cancer has been developed using nonopposed 18 MV photons. This approach has been extended to 6 MV photon application by the addition of one to two fields. These techniques have been optimized to increase sparing of normal liver and bowel, compared with opposed-field methods, to improve patient tolerance of high doses. In this study we compare these techniques in a simulated tumor model in a cylindrical phantom. Dose-volume analysis is used to quantify differences between the conformal, nonopposed techniques with conformal, opposed field methods. This model is also used to evaluate the effect of 1-2 cm setup errors on dose-volume coverage. RESULTS: Dose-volume analysis demonstrates that five-to-six field conformal treatments using 6 MV photons provides similar or better dose coverage and normal tissue sparing characteristics as an optimized 18 MV, four-field approach when 1-2 cm margins are included for setup uncertainty. All approaches using nonopposed beam geometry provide significant reduction in the volume of tissue encompassed by the 30-50% isodose surfaces, as compared with four-field box techniques. CONCLUSIONS: Three-dimensional (3D) conformal treatments can be designed that significantly improve dose-volume characteristics over conventional treatment designs without costing unacceptable amounts of machine time. Further, deep intraabdominal sites can be adequately accessed and treated on intermediate energy machines with a relatively moderate increase in machine time.

Dose-volume histogram analysis of techniques for irradiating pituitary adenomas.

PURPOSE: Three-dimensional treatment planning was performed to evaluate three standard coplanar irradiation techniques (two-field parallel-opposed, three-field, and 110 degrees bilateral arcs), the 330 degrees single rotational arc, and a four noncoplanar arc technique for the treatment of pituitary adenomas. We sought to identify the optimal technique for minimizing the dose delivered to the normal tissues around the pituitary gland. METHODS AND MATERIALS: Contours of the pituitary tumor and normal tissues were traced onto computed axial tomography (CT) scans and reconstructed in three dimensions using a three-dimensional planning system. A total dose of 45 Gy was delivered to the pituitary lesion with the five techniques using 6 MV and 18 MV photons, and dose-volume histograms were generated. RESULTS: The 18 MV photons delivered a lower dose to the temporal lobe than did the 6 MV photons in the two-field technique, but this advantage was not evident for the other techniques. The three-field technique improved dose distribution throughout the temporal lobes with low doses being delivered to the frontal lobe. The bilateral arc and the 330 degrees arc techniques were superior to stationary two- and three-fields techniques for sparing the temporal lobes. The four noncoplanar arc technique delivered less doses to the temporal and frontal lobes than did the other techniques. However, the lens dose (3.6 Gy/25 fractions) was higher compared to the other techniques. CONCLUSION: Analysis of the dose-volume histograms shows the various dosimetric advantages and disadvantages of the five techniques. Based upon individual considerations, including the patient's age and medical history, one can decide the optimal technique for treatment.

Uniform irradiation of the craniospinal axis with a penumbra modifier and an asymmetric collimator.

PURPOSE: A technique is described that uses an independent, asymmetric collimator and a penumbra modifier to uniformly administer radiation over the craniospinal axis. METHOD AND MATERIALS: An isocenter is used at the junction of the cranial and the upper spinal fields. These fields are defined by a single isocenter at spinal cord depth and an independent, asymmetric collimator. From the isocenter, the cranial and upper spinal fields are extended 1 cm inferiorly and superiorly, respectively. A modifier provides a 2-cm wide penumbra at the central axis of the beam (overlapping region) and is attached to a wedge tray in an accessory slot. This modifier allows the fields to be matched so a uniform dose is delivered over the isocenter and junction. Dose distribution was measured with an anthropomorphic head-and-neck wax phantom that included the seventh cervical vertebrae. A film was placed in a coronal cut at the spinal cord level. RESULTS: The administered dose varied less than 10% through the craniospinal axis. Reproducibility with portal films has been very good. Advantages include dose homogeneity, easy reproducibility, and decreased setup time. CONCLUSION: This single-field isocentric technique allows more uniform irradiation of the craniospinal axis than do previously described techniques.

Indications for excluding the seminal vesicles when treating clinically localized prostatic adenocarcinoma with radiotherapy alone.

PURPOSE: The indications for treating the seminal vesicles (SV) in patients with clinically localized carcinoma of the prostate are controversial. We sought to define subgroups of patients in whom coverage could be avoided, using pretreatment prostate specific antigen (PSA) values and the Gleason score. Because the rectum is the major dose-limiting structure, we also measured the extent of rectal sparing achieved by excluding the SV from external beam treatment fields. METHODS AND MATERIALS: We retrospectively studied lateral x-ray simulation films of 43 patients treated with standard four-field radiotherapy and dose-volume histograms of eight patients treated with conformal radiotherapy. The rectal surface areas were measured and the volumes were calculated including and excluding the SV. The pathology reports of patients treated with radical prostatectomy alone between 1987 and 1993 were reviewed. Patients without preoperative PSA levels or biopsy Gleason scores, or who received neoadjuvant hormonal therapy were excluded. Of the 368 remaining patients, 66 (18%) had preoperative PSA levels < or = 4, 172 (47%) had PSA levels 4-10, and 130 (35%) had PSA levels > 10. The Gleason score was < or = 6 in 269 (73%), and 99 (27%) had a score > or = 7. RESULTS: The reduction in the total irradiated rectal areas to full doses when the SV were excluded ranged from 5 to 67% in individual patients (median, 44%). The median reduction in the irradiated rectal volumes to 50% of the prescribed dose, as determined by dose-volume histograms, was 51% (range: 37-76%). The median reduction in bladder volumes was 9% (range: 6%-15%). The incidence of SV involvement was 19% (70 out of 368). Patients with normal PSA levels (< or = 4 ng/mL) had a 3% (2 out of 66) rate of SV involvement. Patients with PSA levels between 4-10 ng/mL had a 8% (10 out of 126) rate of SV involvement. All other cases had at least 20% rate of SV involvement, with a combined rate of 33%. Using a cutoff of 15%, two low risk groups were identified: all patients with PSA levels < or = 4, and patients with PSA 4-10 and Gleason score < or = 6. These constituted 52% (192 out of 368) of all patients. Overall, the low-risk patients had a 6% (12 out of 192) incidence of SV involvement vs. 33% (58 out of 176) for the high risk patients (p < or = .001). CONCLUSIONS: Excluding the SV from the treatment field can significantly reduce (40%-50%) the volume of irradiated rectum. Our data confirm that pretreatment PSA levels and Gleason scores can be effectively used to define subgroups of patients in whom SV irradiation can be avoided. We propose excluding the SV in all patients with PSA levels < or = 4, and patients with PSA levels 4-10 and a Gleason score < or = 6.

Binocularity and spatial frequency dependence of calcarine activation in two types of amblyopia.

OBJECTIVE AND BACKGROUND: Strabismus and anisometropia early in life frequently causes monocular amblyopia. Activation of the visual cortex is compared between the two types of amblyopia to elucidate differences in the pathogenetic mechanism of the disease. METHODS: Using an EPI gradient echo sequence in 1.5T MRI, calcarine activation by monocular viewing of checkerboard patterns with reversal was examined in terms of binocularity of the activation and dependence on the spatial frequency of the stimuli. RESULTS: First, the proportion of voxels activated by both normal and amblyopic eye monocular stimulations is lower in the strabismic group than in the anisometropic group. Second, the activation by higher-spatial-frequency stimuli is reduced in the anisometropic group, but not in the strabismic group. CONCLUSIONS: These findings from the human visual cortex are consistent with the view proposed based on animal research that the loss of binocular interaction and the undersampling of high-spatial-frequency components of visual stimuli are each one of the underlying changes in strabismic and anisometropic amblyopia, respectively.

Deconvolution of detector size effect for small field measurement.

Parametrization of the small fields employed in stereotactic applications is a painstaking process involving extensive film dosimetry to achieve acceptable beam edge definition. Use of cylindrical or spherical detectors for profile measurements would simplify data acquisition but add a volume averaging artifact to beam edge definition. We demonstrate a simple approach to unfolding the chamber size artifact from measured small beam profiles using typical cylindrical chambers. In comparison with film measurements we have found good agreement when the detector response function is deconvoluted from the measured profiles, although the amount of correction needed is fairly minimal for the detectors studied.

Angular measurement of the cobalt-60 emitted radiation spectrum from a radiosurgery irradiator.

The photon energy spectrum emanating from a Leksell Gamma Knife, Model 23004B, was measured between 0.250 and 3.5 MeV with the sources exposed. Measurements were made using a 2x2 inch NaI detector enclosed in a lead-shielded apparatus having a 1/4 inch diameter measurement aperture, which reduced the amount of radiation received by the crystal. All measurements were made one meter above the floor within a quadrant toward one side of the Gamma Knife couch. The measured spectra displayed the expected 60Co doublet of photon peaks at energies of 1.17 and 1.33 MeV. These peaks appeared in spectra beginning at approximately 50 degrees, as one proceeds from a point directly lateral to the source enclosure (0 degrees) toward the foot of the couch (90 degrees). The average photon energy of the spectrum shifts to lower values as the doublet decreases in magnitude with increasing angle until almost vanishing at an angle equal to 90 degrees. Inserting a 16 cm diameter plastic sphere phantom, provided with the Gamma Knife, into the radiation beams increases the low energy photon emissions appearing in the spectrum, especially for measurements at the foot of the couch. Implications for the design of shielding a treatment room containing the Gamma Knife, Model B, and estimation of the radiation exposure to personnel during an emergency procedure in the treatment room with the sources exposed are discussed.

Characterization of a commercial multileaf collimator used for intensity modulated radiation therapy.

The characteristics of a commercial multileaf collimator (MLC) to deliver static and dynamic multileaf collimation (SMLC and DMLC, respectively) were investigated to determine their influence on intensity modulated radiation therapy (IMRT) treatment planning and quality assurance. The influence of MLC leaf positioning accuracy on sequentially abutted SMLC fields was measured by creating abutting fields with selected gaps and overlaps. These data were also used to measure static leaf positioning precision. The characteristics of high leaf-velocity DMLC delivery were measured with constant velocity leaf sequences starting with an open field and closing a single leaf bank. A range of 1-72 monitor units (MU) was used providing a range of leaf velocities. The field abutment measurements yielded dose errors (as a percentage of the open field max dose) of 16.7+/-0.7% mm(-1) and 12.8+/-0.7% mm(-1) for 6 MV and 18 MV photon beams, respectively. The MLC leaf positioning precision was 0.080+/-0.018 mm (single standard deviation) highlighting the excellent delivery hardware tolerances for the tested beam delivery geometry. The high leaf-velocity DMLC measurements showed delivery artifacts when the leaf sequence and selected monitor units caused the linear accelerator to move the leaves at their maximum velocity while modulating the accelerator dose rate to deliver the desired leaf and MU sequence (termed leaf-velocity limited delivery). According to the vendor, a unique feature to their linear accelerator and MLC is that the dose rate is reduced to provide the correct cm MU(-1) leaf velocity when the delivery is leaf-velocity limited. However, it was found that the system delivered roughly 1 MU per pulse when the delivery was leaf-velocity limited causing dose profiles to exhibit discrete steps rather than a smooth dose gradient. The root mean square difference between the steps and desired linear gradient was less than 3% when more than 4 MU were used. The average dose per MU was greater and less than desired for closing and opening leaf patterns, respectively, when the delivery was leaf-velocity limited. The results indicated that the dose delivery artifacts should be minor for most clinical cases, but limit the assumption of dose linearity when significantly reducing the delivered dose for dosimeter characterization studies or QA measurements.

Treating obstructive sleep apnea and snoring: assessment of an anterior mandibular positioning device.

BACKGROUND: Dental devices have been used to help manage snoring and obstructive sleep apnea, or OSA. This article reports on patients' compliance with and complications of long-term use of an anterior mandibular positioning, or AMP, device. METHODS: The device used was a custom-made, two-piece, full-coverage, adjustable acrylic appliance, connected with Herbst attachments. The appliance was used nightly and advanced the mandible by 75 percent of the patient's maximum protrusive distance. Patients were telephoned to determine whether they were still using the AMP device. If not, they were asked when and why they stopped using it. The study sample included 65 consecutive patients with mild-to-moderate obstructive sleep apnea and snoring. RESULTS: Long-term use (three years or more) of the AMP device in these patients was 51 percent (27 of 53 patients). Of the 53 responding patients, 40 percent reported jaw/facial muscle pain, 40 percent had occlusal changes, 38 percent reported tooth pain, 30 percent reported jaw joint pain and 30 percent experienced xerostomia. Of the 27 long-term AMP users, 22 rated themselves as being very satisfied and four as somewhat satisfied; one was neither satisfied nor dissatisfied with the appliance. CONCLUSIONS: It was determined that with use of the AMP device, 40 percent of patients will develop some minor complications of jaw, mouth and/or tooth pain, and approximately 26 percent of long-term users might experience a painless but irreversible change in their occlusion. Annual follow-up office visits with the dentist appear necessary for early detection of these changes. CLINICAL IMPLICATIONS: Patients with mild-to-moderate OSA who receive a two-piece, adjustable AMP device should be informed that 50 percent of patients quit using the device in a three-year period and some will experience shifts in their occlusion.

Risk factors for and clinical implications of mixed Candida/bacterial bloodstream infections.

Mixed Candida/bacterial bloodstream infections (BSIs) have been reported to occur in more than 23% of all episodes of candidaemia. However, the clinical implications of mixed Candida/bacterial BSIs are not well known. We performed a retrospective case-control study of all consecutive patients with candidaemia over a 5-year period to determine the risk factors for and clinical outcomes of mixed Candida/bacterial BSIs (cases) compared with monomicrobial candidaemia (controls). Thirty-seven (29%) out of 126 patients with candidaemia met the criteria for cases. Coagulase-negative staphylococci were the predominant bacteria (23%) in cases. In multivariate analysis, duration of previous hospital stay ≥7 weeks (odds ratio (OR), 2.86; 95% confidence interval (CI), 1.09-7.53), prior antibiotic therapy ≥7 days (OR, 0.33; 95% CI, 0.14-0.82) and septic shock at the time of candidaemia (OR, 2.60; 95% CI, 1.14-5.93) were significantly associated with cases. Documented clearance of candidaemia within 3 days after initiation of antifungal therapy was less frequent in cases (63% vs. 84%; p = 0.035). The difference in the rate of treatment failure at 2 weeks was not significant between cases (68%) and controls (62%; p = 0.55). The crude mortality at 6 weeks and survival through 100 days did not differ between the two patient groups (p = 0.56 and p = 0.80, respectively). Mixed Candida/bacterial BSIs showed a lower clearance rate of candidaemia during the early period of antifungal therapy, although the treatment response and survival rate were similar regardless of concurrent bacteraemia. Further studies on the clinical relevance of species-specific Candida-bacterial interactions are needed.

SU-E-J-113: A New Quantification Measure of the Difference Between Two Organ Contours.

PURPOSE: To develop a measuring method between two contours, which can be used for validating a PTV during IGRT, organ motion and/or deformation studies. METHODS: Quantifying the geometric difference between two organ/target surfaces is essential for Radiation therapy planning and delivery. Point-to-surface distance measures have been utilized to evaluate and visualize the local surface differences. However, previously well-known distance measures have critical shortfalls. Normal distance (ND) measure suffers when the reference surface is strongly curved. Minimum distance (MD) measure (a.k.a. Hausdorff distance) suffers when the test surface is strongly curved. Our new distance measure named Error-Proof Distance (EPD) can deal with both difficult cases.EPD measure calculates the maximum value between the Forward Minimum Distance (FMinD) and the Backward Maximum Distance (BMaxD) at each point. The FMinD denotes the minimum distance to the test surface from a point on the reference surface. The BMaxD means the maximum value among the minimum distances from all points of the test surface to the point on the reference surface. We tested EPD using three 2-D contour examples including a 20mm shifted contour, and two 3-D clinical cases. RESULTS: In case of 2-D contour examples, ND and MD measure failed in strongly curved areas, but EPD measure outperformed the others. The maximum distance measured between a reference and a 20mm shifted test contour should be equal to 20mm, but ND erroneously measured 24mm. Furthermore, ND reported erroneous distances where the reference surface is strongly curved in 3-D clinical cases. CONCLUSIONS: We succeeded to prove that a new EPD is arobust and accurate distance measure to compare two 2D or 3D surfaces. EPD measure can be used to evaluate and visualize the surface difference of organ contours. It is also helpful for proving PTV margin during IGRT, and organ motion and/or deformation studies. This project is partially supported by the Agency for Healthcare Research and Quality (AHRQ) grant 1R18HS017424-01A2.

SU-E-J-87: Building Deformation Error Histogram and Quality Assurance of Deformable Image Registration.

PURPOSE: To quantify the systematic error of a Deformable Image Registration (DIR) system and establish Quality Assurance (QA) procedure. METHODS: To address the shortfall of landmark approach which it is only available at the significant visible feature points, we adapted a Deformation Vector Map (DVM) comparison approach. We used two CT image sets (R and T image sets) taken for the same patient at different time and generated a DVM, which includes the DIR systematic error. The DVM was calculated using fine-tuned B-Spline DIR and L-BFGS optimizer. By utilizing this DVM we generated R' image set to eliminate the systematic error in DVM,. Thus, we have truth data set, R' and T image sets, and the truth DVM. To test a DIR system, we use R' and T image sets to a DIR system. We compare the test DVM to the truth DVM. If there is no systematic error, they should be identical. We built Deformation Error Histogram (DEH) for quantitative analysis. The test registration was performed with an in-house B-Spline DIR system using a stochastic gradient descent optimizer. Our example data set was generated with a head and neck patient case. We also tested CT to CBCT deformable registration. RESULTS: We found skin regions which interface with the air has relatively larger errors. Also mobile joints such as shoulders had larger errors. Average error for ROIs were as follows; CTV: 0.4mm, Brain stem: 1.4mm, Shoulders: 1.6mm, and Normal tissues: 0.7mm. CONCLUSIONS: We succeeded to build DEH approach to quantify the DVM uncertainty. Our data sets are available for testing other systems in our web page. Utilizing DEH, users can decide how much systematic error they would accept. DEH and our data can be a tool for an AAPM task group to compose a DIR system QA guideline. This project is partially supported by the Agency for Healthcare Research and Quality (AHRQ) grant 1R18HS017424-01A2.

Clarithromycin and amikacin vs. clarithromycin and moxifloxacin for the treatment of post-acupuncture cutaneous infections due to Mycobacterium abscessus: a prospective observational study.

An outbreak of post-acupuncture cutaneous infections due to Mycobacterium abscessus occurred in Ansan, Korea, from November 2007 through to May 2008. During this time a prospective, observational, non-randomized study was conducted involving 52 patients that were diagnosed with cutaneous M. abscessus infection. We compared the clinical response between patients treated with clarithromycin plus amikacin regimen and those treated with clarithromycin plus moxifloxacin regimens with regard to time to resolution of the cutaneous lesions. Among the 52 study patients, 33 were treated with clarithromycin plus amikacin, and 19 were treated with clarithromycin plus moxifloxacin. The baseline characteristics for the treatment groups were not significantly different, except for initial surgical excision (n = 27 vs. 6, respectively, p = 0.001). The median time (weeks) to resolution of the lesions in the clarithromycin plus moxifloxacin-treated subjects was significantly shorter than that in the clarithromycin plus amikacin-treated subjects (17 ± 1.1 vs. 20 ± 0.9, respectively, p = 0.017). With adjustments for age, location of lesions, prior incision and drainage, and excision during medical therapy, clarithromycin plus moxifloxacin-treated subjects were more likely to have resolved lesions (hazard ratio, 0.387; 95% confidence interval, 0.165-0.907; p = 0.029). The frequency of drug-related adverse events in the two treatment groups was not significantly different (n = 18 vs. 14, respectively; p = 0.240). The most common adverse event was gastrointestinal discomfort. The results of our study showed that the combination regimen of clarithromycin and moxifloxacin resulted in a better clinical response than a regimen of clarithromycin plus amikacin when used for treatment of cutaneous M. abscessus infection.