Anterioposterior Research Articles

Procrustes analysis of a shape of pediatric supracondylar humerus fractures

Shape of supracondylar fracture of the humeral of pediatric patients is analysed with Procrustes method. XR-images of fractures are considered both in anterio-posterior (AP) view and in a lateral (L) view. Applying Procrustes method for both views mean images are constructed and compared. Variability of shapes is quantified with a shape principal component analysis. Possibility of predictions of typical shape of humeral fracture and its variability using statistical shape analysis offers additional information on injury characteristics important in preoperative planning. Non-parametric tests (permutational and bootstrap) do not indicate statistical difference between Procrustes mean shapes in anterio-posterior and lateral projections. It is shown, however, that AP and L shapes of humeral fractures differ in their variability quantified by shape principal components.

Dosimetric Advantage of Combined IMRT for Whole Lung and Abdomen Irradiation for Wilms Tumor

In patients with Wilms tumor with lung metastases, a cardiac-sparing intensity modulated radiation therapy (CS-IMRT) technique is increasingly being adopted for whole lung irradiation. However, the standard technique for flank and whole abdomen radiation remains 2-dimensional anterioposterior (AP), and overlap at the junction between the whole lung CS-IMRT and abdominal AP fields can result in overdose to normal organs. Here, we compared the dosimetry of patients who received whole lung irradiation and flank or abdominal radiation therapy with CS-IMRT with AP abdominal field (IMRT-AP) versus CS-IMRT with IMRT abdominal field (combined IMRT). We retrospectively reviewed the radiation plans of 2 patients with Wilms tumor who received CS-IMRT and flank or whole abdomen irradiation with a combined IMRT approach. Comparison IMRT-AP plans were generated with equivalent target coverage of 95% receiving the prescribed dose. Maximum doses to normal organs were compared at the junctional overlap. Overlap at the junction between CS-IMRT and abdominal fields resulted in a significantly lower dose with combined IMRT plans compared with IMRT-AP plan. Differences in maximum doses (in cGy) to normal organs between combined IMRT versus IMRT-AP plans were most significant in the vertebral body (patient 1 = 1277 vs 2065; patient 2 = 1334 vs 2287), lungs (patient 1 = 1298 vs 2081; patient 2 = 1234 vs 1820), spinal cord (patient 1 = 1235 vs 1975; patient 2 = 1345 vs 2253), stomach (patient 1 = 1264 vs 1977; patient 2 = 1118 vs 2062), and liver (patient 1 = 1297 vs 1889; patient 2 = 1334 vs 2237). The combined IMRT approach for Wilms patients who require whole lung and abdomen irradiation can provide more uniform dose distribution in the junction area and significantly lower doses to normal organs at the junctional overlap.

Precision shaping of elastic stable intramedullary nail for the treatment of metaphyseal diaphysis junction fracture of the distal radius in children: a preliminary report in two centers

BackgroundThis study introduces a novel retrograde precision shaping elastic stable intramedullary nailing (ESIN-RPS) technique and reports clinical outcomes in pediatric distal radius metaphyseal diaphysis junction (DRMDJ) fracture.MethodsData about DRMDJs were collected from February 1, 2020, to April 31, 2022 at two hospitals, retrospectively. All patients were treated with closed reduction and ESIN-RPS fixation. The operation time, blood loss, fluoroscopy times, alignment, and residual angulation on X-ray were recorded. At the last follow-up, the function of wrist and forearm rotation were evaluated.ResultsTotally, 23 patients were recruited. The mean time of follow-up was 11 months and the minimum was 6 months. The mean operation time was 52 min, and the mean fluoroscopies pulses were 6 times. The postoperative anterioposterior (AP) alignment was 93 ± 4% and the lateral alignment was 95 ± 3%. The postoperative AP angulation was (4 ± 1)°, and the lateral angulation was (3 ± 1)°. At the last follow-up, the evaluation of the Gartland and Werley demerit criteria of wrist revealed 22 excellent cases and 1 good case. The forearm rotation and thumb dorsiflexion functions were not limited.ConclusionThe ESIN-RPS is a novel, safe, and effective method for the treatment of pediatric DRMDJ fracture.

Role of Wnt signaling and planar cell polarity in left-right asymmetry.

Wnt signaling plays essential roles in multiple steps of left-right (L-R) determination in development. First, canonical Wnt signaling is required to form the node, where L-R symmetry breaking takes place. Secondly, planar cell polarity (PCP) driven by non-canonical Wnt signaling polarizes node cells along the anterio-posterior (A-P) axis and provides the tilt of rotating cilia at the node, which generate the leftward fluid flow. Thus, reciprocal expression of Wnt5a/5b and their inhibitors Sfrp1, 2, 5 generates a gradient of Wnt5 activity along the embryo's anterior-posterior (A-P) axis. This polarizes cells at the node, by placing PCP core proteins on the anterior or posterior side of each node cell. Polarized PCP proteins subsequently induce asymmetric organization of microtubules along the A-P axis, which is thought to push the centrally localized basal body toward the posterior side of a node cell. Motile cilia that extend from the posteriorly-shifted basal body is tilted toward the posterior side of the embryo. Thirdly, canonical-Wnt signaling regulates the level and expansion of Nodal activity and establishes L-R asymmetric Nodal activity at the node, the first molecular asymmetry in the mouse embryo. Overall, both canonical and non-canonical Wnt signalings are essential for L-R symmetry breaking.

Above and Beyond: Periorbital Suspension for Endoscopic Access to Difficult Frontal Sinus Pathology.

The periorbital suspension (PS) is an advanced adjunctive technique performed during endoscopic approaches to frontal sinus pathology that would be too far lateral or superior to address using traditional endoscopic transnasal approaches. The objectives of this study are to characterize the utility of this technique for frontal sinus pathology, determine anatomic limitations, and assess clinical outcomes following surgical treatment. Prospective case series. Patient data including demographics, etiology, technique, complications, and clinical follow-up were collected. Preoperative computed tomography scans were reviewed for maximum lateral and superior extent of pathology, supraorbital recess height, anterio-posterior (AP) diameter of the frontal sinus, interorbital distance, and orbital-first olfactory neuron distance. The PS approach was used in 30 surgeries (29 patients) for cerebrospinal fluid leaks (n=5), benign tumors (n=17), malignant tumors (n=5), allergic fungal sinusitis (n=2), and mucocele (n=1) between 2018 and 2020. Approaches included 15 Draf IIB and 15 Draf III frontal sinusotomies. All pathology was surgically accessible using the PS approach and there were no intraoperative or postoperative complications. Postoperative follow-up was 11.7 ± 7.6 months. Mean recorded measurements (in mm) were as follows: maximum lateral extent -15.0 ± 7.7, superior extent 21.2 ± 7.7 in surgical plane and 20.9 ± 9.8 in the vertical plane, supraorbital recess height -2.6 ± 1.9, AP frontal sinus diameter -13.2 ± 4.7, interorbital distance -29.8 ± 5.4, and orbital-olfactory neuron distance -14.8 ± 2.9. The PS technique can be safely and successfully utilized to provide endoscopic endonasal access to lateral and superior frontal sinus pathology. 4 Laryngoscope, 132:538-544, 2022.

Estimation of anatomical dimensions of the thorax from computed tomography images of the adult and pediatric Indian population for developing optimal radiological protocols

Purpose:Ionizing radiation has been extensively used for medical diagnosis since its discovery in 1895; however, excessive use can lead to deleterious effects. Prior knowledge on radiological protocols based on simulations would be a practical tool for optimal use of radiation.Materials and Methods:Scan length of the thorax was measured from computed tomography (CT) topographic images and cross-sections at three levels of the thorax were measured from tomographic images of 500 adults and 340 children who had undergone CT thorax examinations using Centricity workstation software. The effective diameter (ED) of the thorax was calculated from anterio-posterior (AP) and transverse anatomical dimensions.Results:A 17% increase in scan length was observed for 6–10 years age group compared to 0–5 years, whereas there was marginal increase for 11–15 years of age. A 11.5% increase was observed for 16–18 years compared to 11-15 years age group. The cross-sectional phantom dimensions were calculated from ED measurements obtained from three regions of the thorax.Conclusions:This study has provided age- and gender-specific reference scan lengths, AP and transverse dimensions and ED for radiological examinations of the thorax. This information is useful to develop age- and gender-specific preset protocols and fabricate phantoms of the thorax for the pediatric and adult Indian population.

Cognitive Loading Produces Similar Change in Postural Stability in Patients With Chronic Ankle Instability and Controls.

While postural stability is compromised in individuals with chronic ankle instability (CAI), few studies have attempted to examine how performing simultaneous cognitive and balancing tasks may alter the complexity of the center of pressure. The purpose of this study was to compare postural stability in patients with CAI to controls during a dual-task condition via sample entropy. Thirty participants (15 CAI, 15 healthy control) performed 3-trials of single-leg stance for 60-seconds each under two different conditions: single-task and dual-task (serial subtraction). Sample entropy (SampEn), a measure of pattern regularity, was calculated from the center of pressure excursion in the anterio-posterior (AP) and medio-lateral (ML) directions. 2x2 mixed-model ANOVAs determined any differences by task or group (p≤0.05). SampEn-AP decreased in the dual-task condition compared to single-task, single-leg balance across groups (F1,28=8.23, p=0.008, d=0.53). A significant interaction for group by task was found for SampEn-ML (F1,28=4.18, p=0.05), but post hoc testing failed to reveal significant differences. Serial subtraction was completed with significantly fewer errors during dual-task compared to single-task (F1,27=12.75, p=0.001, d=0.66). Patients with CAI do not display differences in regularity of postural stability, even when attention is divided. However, the addition of serial subtraction increased the regularity of AP center-of-pressure motion. Increased regularity may suggest a change in motor control strategy, reducing natural fluctuations and flexibility within movement patterns during more challenging tasks. Clinicians could utilize dual-task situations during rehabilitation of patients with CAI, in order to adequately restore stability and function when attention is divided.

Crawl positioning improves set-up precision and patient comfort in prone whole breast irradiation

Prone positioning for whole-breast irradiation (WBI) reduces dose to organs at risk, but reduces set-up speed, precision, and comfort. We aimed to improve these problems by placing patients in prone crawl position on a newly developed crawl couch (CrC). A group of 10 right-sided breast cancer patients requiring WBI were randomized in this cross-over trial, comparing the CrC to a standard prone breastboard (BB). Laterolateral (LL), craniocaudal (CC) and anterioposterior (AP) set-up errors were evaluated with cone beam CT. Comfort, preference and set-up time (SUT) were assessed. Forty left and right-sided breast cancer patients served as a validation group. For BB versus CrC, AP, LL and CC mean patient shifts were − 0.8 ± 2.8, 0.2 ± 11.7 and − 0.6 ± 4.4 versus − 0.2 ± 3.3, − 0.8 ± 2.5 and − 1.9 ± 5.7 mm. LL shift spread was reduced significantly. Nine out of 10 patients preferred the CrC. SUT did not differ significantly. The validation group had mean patient shifts of 1.7 ± 2.9 (AP), 0.2 ± 3.6 (LL) and − 0.2 ± 3.3 (CC) mm. Mean SUT in the validation group was 1 min longer (P < 0.05) than the comparative group. Median SUT was 3 min in all groups. The CrC improved precision and comfort compared to BB. Set-up errors compare favourably to other prone-WBI trials and rival supine positioning.

Difference of static postural balance in patients with Parkinson's Disease and scans without evidencec of dopaminergic deficits

Differentiating scans without evidence of dopaminergic deficit (SWEDD) from Parkinson's disease (PD) is very important to avoid costly and inappropriate interventions. Little is known of postural balance strategy of SWEDD patients. The purpose of this study was investigate difference of static postural balance between SWEDD and PD patients. Eleven patients with SWEDD, 11 patients with PD and normal subjects were instructed to quietly stand on a force plate in a comfortable self selected stance width. Center of pressure (COP) was measured for quantitative evaluation during static standing. As outcome measure, mean distance, mean velocity, 95% confidence ellipse area, mean frequency, peak frequency and peak power were derived from the COP time series in overall, anterio-posterior (AP) and medio-lateral (ML) directions. ANOVA and post hoc test were evaluated for comparison between SWEDD patients and PD patients. SWEDD patients presented a smaller postural sway size and a more frequent postural sway manly in ML direction (p< 0.05). In contrast, there was no significant differences in mean velocity and peak power (p>0.05). There were no significant difference between SWEDD patients and normal subjects (p>0.05). These results indicate that some COP-based outcome variables might be useful to distinguish SWEDD patients with PD patients. This study suggests that static postural balance test could aid clinicians in the identification of potential SWEDD.

COMPARISON OF STATIC POSTURAL BALANCE IN PATIENTS WITH SWEDDS AND PARKINSON’S DISEASE

Differentiating scans without evidence of dopaminergic deficits (SWEDDs) from Parkinson’s disease (PD) is very important to avoid costly and inappropriate interventions. The postural balance strategy patients with SWEDDs are not clear. This study investigates the difference in static postural balance between patients with SWEDDs and PD. Twenty-two patients (11 SWEDDs and 11 PD groups) and 11 control groups were instructed to quietly stand on a custom-made force platform. The outcome measures were, mean distance, 95% confidence ellipse area, mean velocity, mean frequency, peak frequency and peak power derived from the center of pressure (COP) data in overall, medio-lateral (ML) and anterio-posterior (AP) directions. As statistical analysis, ANOVA and post hoc tests were conducted for comparison of patients with SWEDDs and PD. SWEDDs patients presented a smaller postural sway size and a more frequent postural sway mainly in the ML direction ([Formula: see text]). On the contrary, there were no significant differences in mean velocity and peak power. Also, no significant differences existed between SWEDDs and normal subjects ([Formula: see text]). The results reflect that a few COP-based outcome variables might be useful to distinguish SWEDDs patients from PD patients. This study suggests that a static postural balance test can be used for clinical screening and identification of potential SWEDDs.

Simplifying Tumor Volume Estimation from Linear Dimensions for Intra-Cranial Lesions Treated with Stereotactic Radiosurgery.

Aims:This study aims to derive simple yet robust formula(s) for the calculation of cranial tumor volume using linear tumor dimensions in anterioposterior (AP), mediolateral (ML) and craniocaudal (CC) directions and also propose a reproducible methodology for tumor dimension measurements.Materials and Methods:Magnetic resonance images (MRI) of 337 patients planned for Gammaknife Stereotactic Radiosurgery for different types of brain tumors were analyzed using Leksell Gamma Plan (LGP) software. Tumor volume in three dimensional was outlined and maximum tumor diameters were measured in three orthogonal directions AP, ML, and CC on the MRI. Formulas were derived to calculate tumor volume from AP, ML, and CC diameters using linear regression technique. An agreement between the calculated volume and standard volume observed from LGP software was determined using Bland Altman (B-A) plot. A comparison was made between the volume calculated using traditionally used formula of ellipsoid, standard volume obtained from LGP software and volume calculated from formulas derived in the present study.Results:The tumors were divided into two categories based on their size for better volume prediction. The tumors having product of their diameters in the range 0–2.5cc were called “small tumors” and the formula proposed for their volume estimation (V = 1.513) × (AP × ML × CC) + 0.047 ) was found to predict the tumor volume with an average bias of 0.0005cc. For “large tumors,” having product of diameters in the range 2.5–36cc, the proposed formula (V = 0.444 × (AP × ML × CC) + 0.339 ) predicted the tumor volume with an average bias of 0.007cc.Conclusions:The two formulas proposed in the study are more accurate as compared to the commonly used formula that considers the tumors as ellipsoids. The methodology proposed in the study for measurement of linear tumor dimensions is simple and reproducible.

Spatiotemporal dynamics of odor responses in the lateral and dorsal olfactory bulb.

The mammalian olfactory bulb (OB) plays an essential role in odor processing during the perception of smell. Optical imaging of the OB has proven to be a key tool in elucidating the spatial odor mapping and temporal dynamics that underlie higher-order odor processing. Much is known about the activation of olfactory sensory neuron (OSN) glomerular responses in the dorsal olfactory bulb (dOB) during odor presentation. However, the dorsal bulb provides access to only approximately 25% of all glomeruli, and little is known about how the lateral bulb functions during this critical process. Here, we report, for the first time, simultaneous measurements of OSN glomerular activity from both the dOB and the lateral olfactory bulb (lOB), thus describing odor-specific spatial mapping and the temporal dynamics of olfactory input to both the dorsal and lateral bulb. Odor responses in the lateral bulb tended to be most prominent in the dorso-lateral (D-L) region. Lateral glomeruli became active in a dorso-ventral (D-V) sequence upon odor inhalation, unlike the anterio-posterior (A-P) activity wave typical of the dorsal glomeruli. Across the entire D-L bulb, the spatial organization of these dynamics can be explained neither by the purely mechanosensitive dynamics (to breathing clean air) nor by the response amplitudes across glomeruli. Instead, these dynamics can be explained by a combination of zonal receptor distributions, associated OB projections, and air flow paths across the epithelium upon inhalation. Remarkably, we also found that a subset of OSN glomeruli in the lOB was highly sensitive to extranasal air pressure changes, a response type that has not been reported in dorsal glomeruli.

Postural sway during single-legged standing is dependent on the preceding and subsequent action and supports the stability and mobility trade-off hypothesis in classical dancers

ABSTRACT The details on how the position of balance examination is achieved (preceding movement) and what is happening after (subsequent movement) is scarce. We hypothesised that the postural sway in quiet standing can differ due to demanded stability or mobility associated with the preceding and subsequent action. The body sway will be lower with high stability demand task than a condition with high mobility task. Thirteen female ballet students were examined (aged 15.1 ± 0.95 years). Participants were examined in the single-legged standing position as a part of gait initiation (G-I, high mobility) and termination (G-T, high stability) task with the use of force plate. The following Centre of Pressure (COP) variables were analysed: range and standard deviation of COP position, mean COP velocity for AP (anterio-posterior) and ML (medio-lateral) planes. The results showed that for ML plane, body sway was larger for G-I than G-T task. The lowest values of all variables in AP plane (except the COP range) were for G-T task. This difference, confirm our hypothesis, where this difference is not caused by the skills of the participants, but due to the measuring procedure and motor behaviour before and after achieving the measurement position. Our conclusion is limited to the specific posture and homogenous participants.

Smartphone technology can measure postural stability and discriminate fall risk in older adults

BackgroundFalls are the leading cause of injury related death in older adults. Impaired postural stability is a predictor of falls but is seldom objectively assessed in clinical or home settings. Embedded accelerometers within smartphones offer potential to objectively measure postural stability. The purpose of this study was to determine if a smartphone embedded accelerometer can measure static postural stability and distinguish older adults at high levels of fall risk. MethodsThirty older adults (age: 65.9 ± 8.8) underwent seven balance tests while standing on a force plate and holding a smartphone against their chest in a standardized order. Participants also completed the Physiological Profile Assessment to assess their fall risk. Center of pressure (COP) parameters from the force plate including velocity in the anterioposterior (AP) and mediolateral (ML) directions and 95% confidence ellipse were derived. Maximum acceleration and root mean square (RMS) in ML, AP and vertical axes were derived from the smartphone. Spearman rank-order correlations between force plate and smartphone measures were conducted, and receiver operating characteristic (ROC) and the area under the curves (AUC) were constructed to distinguish between low and high fall risk. ResultsThere were moderate to strong significant correlations between measures derived from the force plate and measures derived from the smartphone during challenging balance conditions (ρ = 0.42–0.81; p < 0.01–0.05). The AUC for ROC plots were significant for all COP measures during challenging balance conditions (p < 0.01–0.05). The AUC for ROC plots were significant for RMS vertical and AP during challenging balance conditions (p = 0.01–0.04). SignificanceThis study provides evidence that a smartphone is a valid measure of postural stability and capable of distinguishing fall risk stratification in older adults. There is potential for smartphones to offer objective, fall risk assessments for older adults.

Comparison of Different Registration Methods on Patient Set-Up Error During Volumetric Modulated Arc Therapy Using Cone-Beam CT Imaging for Lung Cancer

Background: The three-dimensional image-guided radiation therapy is very important in volumetric modulated arc therapy (VMAT) to enhance accuracy throughout the course of a patient's radiation treatment. The image guidance can ensure the safe administration of prescribed radiation dose to the patient. Aim: This study investigated patient set-up uncertainties based on three different registration methods in cone bean CT (CBCT) using volumetric modulated arc therapy (VMAT) for different clinical sites. Methods: A total of 396 CBCT performed for lung VMAT plan for patient set-up verification as per institution image guidance protocol. The approved CT images were transferred from treatment planning system (TPS) to x-ray volumetric imaging system (XVI) for reference image registration. The set-up errors in mediolateral (ML), craniocaudal (CC) and anterioposterior (AP) direction were determined using grayscale matching between the reference CT image and onboard CBCT images. For the current study, patient set-up verification was performed based on clip-box registration (CBR) for image matching. By considering clip-box registration as a reference, other two registration methods of mask registration (MR) and dual registration (DR) (clip-box and mask) were performed for comparison. To compare three registration methods, systematic error (∑), random error (σ), mean displacement, mean set-up error and maximum error were analyzed. Results: The systemic and random errors were less in clip-box registration as compared with other two registration ( P &gt; 0.05). Similarly, maximum error, mean displacement error and mean set-up errors were observed less in clip-box registration as compared with mask and dual registration ( P &gt; 0.05). However, statically no significant difference was observed between three different registration methods ( P &gt; 0.05). Conclusion: All three registration methods can be used for patient set-up accuracy for lung VMAT plan. However, the current study suggested that clip-box method will be more efficient as compared with mask and dual registration methods.

Low intensity vibration of ankle muscles improves balance in elderly persons at high risk of falling.

In our study we examined postural performance of young healthy persons (HY), elderly healthy persons (HE), and elderly persons at high risk of falling (FR). Anterio-posterior (AP) and medio-lateral (ML) ankle and hip angular deviations, as well as linear displacements of the center of mass (COM) were assessed in persons standing with eyes either open or closed, while none, and 40 and 30 Hz vibrations were applied bilaterally to the ankle muscle gastrocnemius. During quiet standing with eyes open, balance parameters in FR group differed from those in healthy groups. ML ankle and hip angular deviations, as well as COM linear displacements were noticeably larger in FR group. During quiet standing with eyes closed, all balance parameters in participants of all groups had a clear trend to increase. During standing with eyes open, 40 Hz vibration increased all but one balance parameter within HY group, ankle angular deviations in HE group, but none in FR group. In response to 30 Hz vibration, only ankle angular deviations and COM linear displacements increased in HY group. There were no changes in both elderly groups. During standing with eyes closed, 40 and 30 Hz vibrations did not produce consistent changes in balance parameters in HY and HE groups. In FR persons, 40 Hz vibration did not change balance parameters. However, in FR groups, 30 Hz vibration decreased ankle and hip angular deviations, and COM linear displacements. The major result of the study is a finding that low intensity vibration of ankle muscles makes balance better in elderly persons at high risk of falling. This result is clinically relevant because it suggests that applying mild vibration to ankle muscles while standing and walking might benefit elderly persons, improving their postural performance and reducing a risk of unexpected falls.

Commissioning and validation of commercial deformable image registration software for adaptive contouring

PurposeTo report the commissioning and validation of deformable image registration(DIR) software for adaptive contouring. MethodsDIR (SmartAdapt®v13.6) was validated using two methods namely contour propagation accuracy and landmark tracking, using physical phantoms and clinical images of various disease sites. Five in-house made phantoms with various known deformations and a set of 10 virtual phantoms were used. Displacement in lateral, anterio-posterior (AP) and superior-inferior (SI) direction were evaluated for various organs and compared with the ground truth. Four clinical sites namely, brain (n = 5), HN (n = 9), cervix (n = 18) and prostate (n = 23) were used. Organs were manually delineated by a radiation oncologist, compared with the deformable image registration (DIR) generated contours. 3D slicer v4.5.0.1 was used to analyze Dice Similarity Co-efficient (DSC), shift in centre of mass (COM) and Hausdorff distances Hf95%/avg. ResultsMean (SD) DSC, Hf95% (mm), Hfavg (mm) and COM of all the phantoms 1–5 were 0.84 (0.2) mm, 5.1 (7.4) mm, 1.6 (2.2) mm, and 1.6 (0.2) mm respectively. Phantom-5 had the largest deformation as compared to phantoms 1–4, and hence had suboptimal indices. The virtual phantom resulted in consistent results for all the ROIs investigated. Contours propagated for brain patients were better with a high DSC score (0.91 (0.04)) as compared to other sites (HN: 0.84, prostate: 0.81 and cervix 0.77). A similar trend was seen in other indices too. The accuracy of propagated contours is limited for complex deformations that include large volume and shape change of bladder and rectum respectively. Visual validation of the propagated contours is recommended for clinical implementation. ConclusionThe DIR algorithm was commissioned and validated for adaptive contouring.

Utility of the Three-Point Index in the determination of reduction loss during the conservative treatment of pediatric forearm mid-third fractures.

Forearm fractures constitute approximately 40% of all pediatric fractures. Generally, in conservative treatment,a plaster cast is applied with the elbow in 90° flexion. Success of the treatment depends on theprevention of the reduction in the correct position and suitable duration of the plaster cast. Failure, or the risk of angulation within the cast, is associated with movement within the cast. The aim of this study was to evaluate the applicability of the Cast Index (CI) and Three-Point Index (TPI) measurements, which indicate the loss of reduction, in pediatric mid-third forearm fractures. The hypothesis of the study was that as edema decreases and deformity of the plaster cast occurs after fracture reduction, TPI and CI should be examined during follow-up, as they indicate shifting due to movement within the plaster cast. This retrospective study included a total of 48 patients, who were treated with closed reduction and long-arm plaster cast for a mid-third forearm diaphyseal fracture at our Emergency Polyclinic between March and September 2014. The mean age of the patients was 8.15±3.19 years (range, 5-14 years). Patients were excluded from the study if they had isolated radial or ulnar fracture, open fractures, concomitant fracture or systemic disease (bone metabolism disease, etc), and <10° fracture angulation in the ulna and radius on the initial radiograph and if they did not followup. TPI and CI values were calculated on anterioposterior (AP) and lateral radiographs in the Picture Archiving Communication Systems. In the AP plane, compared with TPI values after reduction, statistically significant increases were observed in TPI values 10 days after reduction (p<0.01). However, no significant difference was observed between those with and without reduction loss in TPI values in the AP plane (p>0.05). Although there was a statistically significant increase in TPI values 15 daysafter reduction compared with the values immediately after reduction, a significant difference between those with and without reduction loss was observed only on lateral TPI. In cases of pediatric forearm diaphyseal fracture, ulnar TPI examined in the lateral plane can be used in monitoring the fracture in a plaster cast applied after the reduction.

A Pilot Study: The Role of Radio-Opaque Hydrogel Tissue Marker in the Treatment of Postprostatectomy Intensity Modulated Radiation Therapy

It is well documented that the prostate bed is highly susceptible to inter-fraction motion leading to larger treatment planning margins to account for daily treatment set up uncertainties when matching to bony anatomy. The use of fiducial markers in the prostate bed has significantly improved accuracy of treatment delivery. This pilot study aims to investigate the role and benefits of radio-opaque hydrogel tissue marker in the treatment of post prostatectomy intensity modulated radiation therapy (IMRT). Twenty patients treated with IMRT to a dose of 70.2Gy in 39 fractions between Jan 2016 to Jan 2017 were included in this study. All patients underwent transperineal injection of hydrogel tissue marker at the level of vesico-urethral anastomosis and cystoscopically into the posterior bladder wall. Instructions for bladder and bowel preparation to be followed during CT simulation and daily treatments were provided to the patients. Daily on-line cone beam CT matching to the hydrogel tissue marker was performed prior to each treatment and off-sets relative to skin tattoos were recorded in 3 directions: left-right (LR); superior-inferior (SI) and anterio-posterior (AP). Daily image registration using bony matching was then assessed off-line and off-sets relative to skin tattoos were again recorded. The mean and standard deviation of the differences between the hydrogel tissue markers and bony off-sets were calculated for all fractions for each patient; then the overall mean and systematic (Σ) and random errors (σ) for the entire cohort were calculated. The planning target volume (PTV) margin required for bony matching was estimated using van Herk's formula of 2.5Σ + 0.7σ, which is designed to ensure a minimum dose of 95% of prescribed dose to the clinical target volume (CTV) in 90% of patients. These margins are relative to the hydrogel tissue markers which are assumed to be in the target tissue. A total of 1520 images were analysed. The overall mean shift differences between the hydrogel tissue markers and bones for the entire cohort were LR: 0.13mm (Σ 0.38mm, σ 1.35mm); SI: 0.92mm (Σ 1.40mm, σ 2.50mm) and AP: 0.40mm (Σ 1.98mm, σ 3.18mm). The calculated PTV margins for bony matching relative to hydrogel tissue markers were 1.90mm in LR, 5.25mm in SI and 7.17mm AP directions. Prostate bed motion is independent of pelvic bone anatomy and soft tissue matching has shown to be superior compared with pelvic bone matching. With a required PTV margin of 7.17mm in the AP direction, the use of hydrogel tissue marker can significantly improve treatment set up accuracy even in patients with optimal bowel and bladder preparations who undergo image guidance with pelvic bone matching. This will provide the best CTV coverage whilst minimising the current PTV margin and mitigating bladder and rectal toxicities.

Evaluation of Cast Re-Orientation on a Dental Surveyor Using Three Tripod Techniques: A Survey and In Vitro Study.

To survey different educational levels (i.e., students, interns, technicians, and prosthodontic faculty) with regard to their opinions, attitudes, and adoption of three selected tripod techniques. The study will also investigate the accuracy of these techniques to reposition casts on the dental surveyor in anterio-posterior (AP) and lateral directions at both technique and educational levels. Tripod points, scored lines, and cemented post tripod techniques were used in this study. Three Kennedy class II modification I stone casts, duplicated from a standard cast, were assigned to each of the tripod techniques. The tilt angles of all casts were set on the dental surveyor to 10° (control angle) in AP and lateral directions using a digital angle gauge with an accuracy of 0.2°. The casts were tripoded accordingly. A total of 243 participants were involved in this study. Participants were first asked to remount the three casts on three different dental surveyors using the tripod technique noted on each cast. Questionnaires were then given to each participant in an individual interview setting; this assured a 100% response rate. The angle differences were calculated. All data were coded and entered into an Excel Spreadsheet file. Statistical analyses were performed using a paired Chi-square, Wilcoxon Matched-pairs, ANOVA, and Tukey post hoc tests at 5% level of significance. No significant difference was found between the educational levels relative to the responses to technique demands, sensitivity, and time required for reorientation (p = 0.08202, 0.8108, 0.6874, respectively); however, the majority of respondents reported low technique demands, low sensitivity, and time saving for technique C in comparison to techniques A and B. Significant differences were noted among the educational levels in response to preference and adoption questions (p = 0.0035 and 0.0015, respectively). The highest percentage of faculty chose technique A for inclusion into the academic curriculum. Wilcoxon Matched-pairs test revealed that technique C was the least difficult and most practical (p = 0.0001, 0.0427, respectively). One-way ANOVA revealed significance in angle differences from the set position for technique A in lateral tilt and techniques A and B in AP tilt (p = 0.0466, 0.0194, 0.0424, respectively). A comparison of positivity (overtilt) and negativity (undertilt) between the three techniques in lateral and AP tilts using Chi-square test resulted in significant differences in both directions of tilt (p < 0.0001). Technique C resulted in remounting the casts at the control position in 15.64% in both directions; this was a higher percentage than the other two techniques (A and B). Wilcoxon Matched-pairs test was used to compare between the techniques relative to angle differences from the standard position. No differences were found between technique A and B in lateral tilt position (p = 0.9271), while significance was detected in AP tilt (p < 0.0001). Significant differences were detected between technique C in comparison to A (p < 0.0001, p = 0.0303) and B (p < 0.0001) in lateral and AP tilt directions. Within the limitations of this study, it can be concluded that technique C (cemented post technique) was more favored among the respondents across all educational levels. This technique presented high potential in accurately reorienting casts on the dental surveyor in comparison to the tripod points and scoring techniques (p < 0.0001).