Factors Associated with Return to Work Postinjury: Can the Modified Rankin Scale Be Used to Predict Return to Work?

The ability to return to work (RTW) postinjury is one of the primary goals of rehabilitation. The modified Rankin Scale (mRS) is a validated simple scale used to assess the functional status of stroke patients during rehabilitation. We sought to determine the applicability of mRS in predicting RTW postinjury in a general trauma population. The trauma registry was queried for patients, aged 18 to 65 years, discharged from 2012 to 2013. A telephone interview for each patient included questions about employment status and physical ability to determine the mRS. Patients who had RTW postinjury were compared with those who had not (nRTW). Two hundred and thirty-four patients met the inclusion criteria. Of these, 171 (72.5%) patients RTW and 63 (26.7%) did nRTW. Patients who did nRTW were significantly older, had longer length of stay and higher rates of in-hospital complications. Multivariate analysis revealed that older patients were less likely to RTW (odds ratio = 0.961, P = 0.011) and patients with a modified Rankin score ≤2 were 15 times more likely to RTW (odds ratio = 14.932, P < 0.001). In conclusion, an mRS ≤2 was independently associated with a high likelihood of returning to work postinjury. This is the first study that shows applicability of the mRS for predicting RTW postinjury in a trauma population.

Factors Associated with Return to Work Postinjury: Can the Modified Rankin Scale be Used to Predict Return to Work?

The ability to return to work (RTW) postinjury is one of the primary goals of rehabilitation. The modified Rankin Scale (mRS) is a validated simple scale used to assess the functional status of stroke patients during rehabilitation. We sought to determine the applicability of mRS in predicting RTW postinjury in a general trauma population. The trauma registry was queried for patients, aged 18 to 65 years, discharged from 2012 to 2013. A telephone interview for each patient included questions about employment status and physical ability to determine the mRS. Patients who had RTW postinjury were compared with those who had not (nRTW). Two hundred and thirty-four patients met the inclusion criteria. Of these, 171 (72.5%) patients RTW and 63 (26.7%) did nRTW. Patients who did nRTW were significantly older, had longer length of stay and higher rates of in-hospital complications. Multivariate analysis revealed that older patients were less likely to RTW (odds ratio = 0.961, P = 0.011) and patients with a modified Rankin score ≤2 were 15 times more likely to RTW (odds ratio = 14.932, P < 0.001). In conclusion, an mRS ≤2 was independently associated with a high likelihood of returning to work postinjury. This is the first study that shows applicability of the mRS for predicting RTW postinjury in a trauma population.

Fast nastic motion of plants and bioinspired structures

The capability to sense and respond to external mechanical stimuli at various timescales is essential to many physiological aspects in plants, including self-protection, intake of nutrients and reproduction. Remarkably, some plants have evolved the ability to react to mechanical stimuli within a few seconds despite a lack of muscles and nerves. The fast movements of plants in response to mechanical stimuli have long captured the curiosity of scientists and engineers, but the mechanisms behind these rapid thigmonastic movements are still not understood completely. In this article, we provide an overview of such thigmonastic movements in several representative plants, including Dionaea, Utricularia, Aldrovanda, Drosera and Mimosa. In addition, we review a series of studies that present biomimetic structures inspired by fast-moving plants. We hope that this article will shed light on the current status of research on the fast movements of plants and bioinspired structures and also promote interdisciplinary studies on both the fundamental mechanisms of plants' fast movements and biomimetic structures for engineering applications, such as artificial muscles, multi-stable structures and bioinspired robots.

Reconstruction of the treatment area by use of sinogram in helical tomotherapy

BACKGROUND

TomoTherapy (Accuray, USA) has an image-guided radiotherapy system with a megavoltage (MV) X-ray source and an on-board imaging device. This system allows one to acquire the delivery sinogram during the actual treatment, which partly includes information from the irradiated object. In this study, we try to develop image reconstruction during treatment with helical tomotherapy.

FINDINGS

Sinogram data were acquired during helical tomotherapy delivery using an arc-shaped detector array that consists of 576 xenon-gas filled detector cells. In preprocessing, these were normalized with full air-scan data. A software program was developed that reconstructs 3D images during treatment with corrections as; (1) the regions outside the field were masked not to be added in the backprojection (a masking correction), and (2) each voxel of the reconstructed image was divided by the number of the beamlets passing through its voxel (a ray-passing correction). The masking correction produced a reconstructed image, however, it contained streak artifacts. The ray-passing correction reduced this artifact. Although the SNR (the ratio of mean to standard deviation in a homogeneous region) and the contrast of the reconstructed image were slightly improved with the ray-passing correction, use of only the masking correction was sufficient for the visualization purpose.

CONCLUSIONS

The visualization of the treatment area was feasible by using the sinogram in helical tomotherapy. This proposed method would be useful in the treatment verification.

Panel-based testing for inherited colorectal cancer: a descriptive study of clinical testing performed by a US laboratory

Next-generation sequencing enables testing for multiple genes simultaneously (‘panel-based testing’) as opposed to sequential testing for one inherited condition at a time (‘syndrome-based testing’). This study presents results from patients who underwent hereditary colorectal cancer (CRC) panel-based testing (‘ColoNext™’). De-identified data from a clinical testing laboratory were used to calculate (1) frequencies for patient demographic, clinical, and family history variables and (2) rates of pathogenic mutations and variants of uncertain significance (VUS). The proportion of individuals with a pathogenic mutation who met national syndrome-based testing criteria was also determined. Of 586 patients, a pathogenic mutation was identified in 10.4%, while 20.1% had at least one VUS. After removing eight patients with CHEK2 mutations and 11 MUTYH heterozygotes, the percentage of patients with ‘actionable’ mutations that would clearly alter cancer screening recommendations per national guidelines decreased to 7.2%. Of 42 patients with an ‘actionable’ result, 30 (71%) clearly met established syndrome-based testing guidelines. This descriptive study is among the first to report on a large clinical series of patients undergoing panel-based testing for inherited CRC. Results are discussed in the context of benefits and concerns that have been raised about panel-based testing implementation.

Conflict of interest

Cristi Radford and Jill Dolinsky are full-time employees for the commercial laboratory Ambry Genetics, which performs ColoNext™ testing. Elizabeth Chao is a paid consultant for Ambry. Deborah Cragun, Meghan Caldwell, and Tuya Pal report no potential conflicts of interest. Specifically, they are not employed by Ambry, and they did not receive any financial or other incentives from Ambry.

Quantitative characterization of tomotherapy MVCT dosimetry

Megavoltage computed tomography (MVCT) is used as image guidance for patient setup in almost every tomotherapy treatment. Frequent use of ionizing radiation for image guidance has raised concern of imaging dose. The purpose of this work is to quantify and characterize tomotherapy MVCT dosimetry. Our dose calculation was based on a commissioned dose engine, and the calculation result was compared with film measurement. We studied dose profiles, center dose, maximal dose, surface dose, and mean dose on homogeneous cylindrical water phantoms of various diameters for various scanning parameters, including 3 different jaw openings (of nominal value J4, J1, and J0.1) and couch speeds (fine, normal, and coarse). The comparison between calculation and film measurement showed good agreement. In particular, the thread pattern on the film of the helical delivery matched very well with calculation. For the J1 jaw and coarse imaging mode, the maximum difference between calculation and measurement was about 6% of the center dose. Calculation on various sizes of synthesized phantoms showed that the center dose decreases almost linearly as the phantom diameter increases, and that the fine mode (couch speed of 4mm/rotation) received twice the dose of the normal mode (couch speed of 8mm/rotation) and 3 times that of the coarse mode (couch speed of 12mm/rotation) as expected. The maximal dose ranged from 100% to ∼200% of the center dose, with increasing ratios for larger phantoms, smaller jaws, and faster couch speed. For all jaw settings and couch speeds, the mean dose and average surface dose vary from 95% to 125% of the center dose with increasing ratios for larger phantoms. We present a quantitative dosimetric characterization of the tomotherapy MVCT in terms of scanning parameters, phantom size, center dose, maximal dose, surface dose, and mean dose. The results can provide an overall picture of dose distribution and a reference data set that enables estimation of CT dose index for the tomotherapy MVCT.

High-dose MVCT image guidance for stereotactic body radiation therapy

PURPOSE

Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance.

METHODS

Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison.

RESULTS

MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp∕mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable.

CONCLUSIONS

High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.

Estimating influenza incidence and rates of influenza-like illness in the outpatient setting

Please cite this paper as: Fowlkes et al. (2012) Estimating influenza incidence and rates of influenza‐like illness in the outpatient setting. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12014.

Background:  Estimating influenza incidence in outpatient settings is challenging. We used outpatient healthcare practice populations as a proxy to estimate community incidence of influenza‐like illness (ILI) and laboratory‐confirmed influenza‐associated ILI.

Methods:  From October 2009 to July 2010, 38 outpatient practices in seven jurisdictions conducted surveillance for ILI (fever with cough or sore throat for patients ≥2 years; fever with ≥1 respiratory symptom for patients <2 years). From a sample of patients with ILI, respiratory specimens were tested for influenza.

Results:  During the week of peak influenza activity (October 24, 2009), 13% of outpatient visits were for ILI and influenza was detected in 72% of specimens. For the 10‐month surveillance period, ILI and influenza‐associated ILI incidence were 20·0 (95% CI: 19·7, 20·4) and 8·7/1000 (95% CI: 8·2, 9·2) persons, respectively. Influenza‐associated ILI incidence was highest among children aged 2–17 years. Observed trends were highly correlated with national ILI and virologic surveillance.

Conclusions:  This is the first multistate surveillance system demonstrating the feasibility of using outpatient practices to estimate the incidence of medically attended influenza at the community level. Surveillance demonstrated the substantial burden of pandemic influenza in outpatient settings and especially in children aged 2–17 years. Observed trends were consistent with established syndromic and virologic systems.

TU-E-BRA-07: Post-Operative Eye Plaque Imaging Using Tomotherapy MVCT

PURPOSE

Intra-operative ultrasound is used to verify the positioning of episcleral eye plaques used to treat ocular melanoma. Ultrasound can be ambiguous because of image artifacts, and plaques may shift position after surgery. Ultrasound verification is particularly challenging for anterior tumors. Post-operative imaging could be used to trigger interventions that would prevent local treatment failure. We investigated if, and under what conditions, the Tomotherapy megavoltage computed tomography (MVCT) system could be used to perform post-implantation verification of eye plaque positioning.

METHODS

Plaques were placed on a preserved cow's eye, and imaged with the megavoltage CT of a Tomotherapy linear accelerator (Accuray, Sunnyvale, CA). The images were visually and quantitatively assessed to determine if they were of sufficient quality to verify tumor coverage and plaque tilt with respect to the sclera. We used the visibility of the lens as a proxy for visibility of a tumor. To test the utility of hypothetical higher beam current Tomotherapy images, we averaged sequential images of the same setup.

RESULTS

The plaque, the lens of the eye, and the globe are visible in the images. The CNR of the lens with respect to the vitreous was 5.6 for a single image. For 10 images averaged, the CNR was 9.2. Estimated dose from a single image was 1.3 cGy (body CTDIvol); even 10 times this dose would be an acceptable image-guidance dose for radiotherapy patients. One limitation of the imaging procedure is the long scan time (up to 240 seconds), during which time any significant patient motion would lead to image artifacts. Human trials on eye plaque patients are planned.

CONCLUSIONS

Tomotherapy MVCT imaging could be used to verify tumor coverage and plaque tilt after episcleral plaque implantation. Tumors should be visible in standard Tomotherapy images but higher beam current images would be preferred if available.

TU-E-BRA-06: Evaluation of a New MV X-Ray Detector Designed for the TomoTherapy® System

PURPOSE

To evaluate the performance of a new MV X-ray detector prototype specifically designed for use on the TomoTherapy® System.

METHODS

A gas-filled detector array, similar in concept to existing TomoTherapy detector arrays, has been designed and fabricated for the TomoTherapy System. Unlike existing detector arrays, the prototype detector array has a radius of curvature that matches the source-to-detector distance. Also, the internal structure of the detector such as the septa material and geometry has been optimized for MV X-rays. The prototype detector performance was assessed by measuring the signal properties of each of the detector channel signals. Signal, noise, and signal-to-noise ratios (SNR) were measured. Finally, the resulting MVCT image quality was assessed.

RESULTS

The signal profile across the prototype detector more closely matches the incident X-ray beam intensity and, in particular, is missing the characteristic trough in the center of signal profiles from existing TomoTherapy detector arrays. Compared to an existing detector, the mean signal is approximately equal outside the central region. Inside the 100 central channels (out of 576 total channels), the prototype detector signal is substantially larger than the existing detector. The variation in the pulse-to-pulse signal (noise), after accounting for output fluctuations, is substantially lower with the new detector. The resulting SNR is an average of 18% higher across all channels, with an improvement of up to 36% for the central channels. The prototype detector yielded MVCT images that, compared to one typical system with an existing detector array, had 7% lower image noise in the periphery and 36% lower noise at the center of the image.

CONCLUSIONS

This evaluation indicates that the performance of a new MV X-ray detector array prototype exceeds the performance of an existing detector array in terms of signal-to-noise ratio and resulting MVCT image quality.

Laparoscopic sleeve gastrectomy for obesity: can it be considered a definitive procedure?

BACKGROUND

Providing bariatric surgery services to an inner-city population is a challenge. Laparoscopic sleeve gastrectomy (LSG) is an effective operation for morbid obesity with a relatively low complication rate. LSG appears to be a suitable alternative procedure for this group of patients.

METHODS

This is a retrospective review and analysis of the experience with 185 consecutive LSGs that had completed at least 6 months follow-up. Eleven conversions from LSG to laparoscopic Roux-en-Y gastric bypass were excluded, leaving 174 patients for outcome analysis. Data collected were patient demographics, body mass index (BMI), comorbid conditions, operating time, length of hospital stay, and perioperative complications. Weight loss and resolution/improvement of comorbidities were analyzed.

RESULTS

Mean patient age was 39.58 years and mean BMI was 48.97 kg/m(2). The percentage of patients with BMI > 50 kg/m(2) was 37.94%. Mean excess weight loss (EWL) was 44.76, 55.52, 59.22, and 58.92% at 6, 12, 24, and 36 months, respectively. Six patients (3.24%) lost less than 25% EWL. Thirteen patients (7.02%) regained an average of 13 lb after reaching a plateau. Resolution/improvement of comorbidities was 84% for diabetes mellitus, 49.99% for hypertension, 90% for asthma, 90.74% for obstructive sleep apnea, and 45.92% for gastroesophageal reflux disease symptoms (GERD). The mortality rate was zero in this series. Perioperative complications occurred in 26 patients (14.05%): four staple-line leaks (2.16%), four bleeds (2.16%), four obstructions (2.16%), five vomiting/dehydration (2.70%), six new onset of GERD symptoms (3.24%), two with pneumonia (1.08%), and one with pulmonary embolism (0.54%).

CONCLUSION

LSG results in stable and adequate weight loss with resolution/improvement in comorbidities in a high percentage of patients. It can be considered a definitive operation for morbid obesity.

A slit method to determine the focal spot size and shape of TomoTherapy system

PURPOSE

To obtain accurate x-ray source profile measurements using a slit-collimator, the slit-collimator should have a narrow width, large height, and be positioned near the source. However, these conditions may not always be met. In this paper, the authors provide a detailed analysis of the slit measurement geometry and the relationship between the slit parameters and the measured x-ray source profile. The slit model allows the use of a shorter and more easily available slit-collimator, while accurate source profile measurements can still be obtained.

METHODS

Measurements were performed with a variety of slit widths and/or slit to source distances. The relationship derived between the slit parameters and the measured profile was used to determine the true focal spot profile through a least square fit of the profile data. The model was verified by comparing the predicted profiles at a variety of slit-collimator parameters with the measured results on the TomoTherapy Hi-Art system.

RESULTS

Both the treatment beam and the imaging beam were measured. For treatment mode, it was found that a source consisting of one Gaussian with a 0.75 mm full-width-half-maximum (FWHM) and 72% peak amplitude and a second Gaussian with a 2.27 mm FWHM and 18% peak amplitude matched measurement profiles. The overall source profile has a FWHM of 0.93 mm, but with a higher amplitude in the tail region than a single Gaussian. For imaging mode, the source consists of one Gaussian with a 0.68 mm FWHM and 82% peak amplitude and a second Gaussian with a 1.83 mm FWHM and 18% peak amplitude. The overall source profile has a FWHM of 0.77 mm.

CONCLUSIONS

Our study of the focal spot measurement using slit-collimators showed that accurate source profile measurements can be achieved through fitting of measurement results at different slit widths and source-to-slit distances (SSD). Quantitative measurements of the TomoTherapy linac focal spot showed that the source distribution could be better described with a model consisting of two Gaussian components rather than a single Gaussian model as assumed in previous studies.

Effects of intensive insulin therapy alone and with added pioglitazone on renal salt/water balance and fluid compartment shifts in type 2 diabetes

OBJECTIVE

To evaluate the effects of intensive insulin therapy alone or with added pioglitazone on renal salt/water balance and body fluid compartment shifts in type 2 diabetes.

METHODS

A total of 25 insulin-treated, obese patients with type 2 diabetes were randomized to pioglitazone 45 mg (n = 12) or placebo (n = 13) and treated intensively for 12-16 weeks to achieve equivalent glycaemic control. We measured total body water (TBW) and extracellular/intracellular fluid by bioimpedance analysis; plasma/RBC volume with I(131)albumin; sodium handling by fractional excretion of sodium/lithium (FeNa/FeLi) and other renal/hormonal parameters.

RESULTS

Intensification of insulin therapy and the addition of pioglitazone significantly improved glycaemia (HbA1C 7.8-7.2% and 7.6-7.1%) and increased body weight (1.7 and 4.9 kg) respectively. TBW increased 1.7 l with insulin alone (65% intracellular) and 1.6 l with added pioglitazone (75% extracellular) (p = 0.06 and 0.09 respectively). Plasma volume increased 0.2 +/- 0.1 l with insulin alone (p = 0.05) and 0.4 +/- 0.1 l with added pioglitazone (p < 0.05). Extravascular, extracellular (interstitial) fluid increased significantly and more with added pioglitazone (0.8 +/- 0.2 l, p < 0.01) than with insulin alone (0.4 +/- 0.2 l, p = ns). At steady-state, FeLi (marker of proximal-tubular sodium delivery to the distal nephron) increased significantly with added pioglitazone (12.4 +/- 1.3 to 18.0 +/- 3.2%) vs. no significant change with insulin alone (15.4 +/- 1.2 to 14.5 +/- 2.3%). There were no significant changes in the other parameters.

CONCLUSION

In intensively insulin-treated obese type 2 diabetic patients, at equivalent glycaemic control, the addition of pioglitazone causes greater weight gain, but a similar increase in body water that is mainly extracellular and interstitial compared with intracellular increase with insulin therapy alone. Pioglitazone also increases the filtered load of sodium reabsorbed at the distal nephron with no net change in FeNa.