Wall Rib Research Articles

Characterization of Chest Wall Toxicity After Stereotactic Body Radiation Therapy to the Liver

Chest wall rib fractures are frequent complications after thoracic stereotactic body radiation therapy (SBRT). While well described for lung SBRT, limited data exists on the frequency and predictors for chest wall toxicity with SBRT to the liver for primary or metastatic lesions. We aimed to characterize the clinical, demographic and dosimetric factors of rib fractures.A chart review identified 283 patients (204 male and 79 female) who received liver SBRT from 2014-2019. Univariate logistic regression models were used to identify demographic, clinical, and dosimetric factors associated with the development of rib fractures post liver SBRT. All statistical tests were two-sided and the null hypothesis was rejected for P < 0.05.The median follow-up was 12.2 months (range: 3-78.8 months). With respect to primary site, 81% were primary liver tumors and 19% metastases. SBRT doses ranged from 60 Gy in 5 fractions to 30 Gy in 5 fractions. The most commonly used doses were: 40 Gy in 5 fractions (29%), 45 Gy in 5 fractions (23%), 50 Gy in 5 fractions (18%), 35 Gy in 5 fractions (9%), 48 Gy in 3 fractions (8%), and 30 Gy in 5 fractions (5%). Mean PTV volume was 141 cc (range: 3.7 - 1304 cc). A total of 22 patients (8%) experienced rib fractures. Of these patients, three (17.6%) and one (6%) underwent two and three liver SBRT courses, respectively. The earliest rib fracture was seen 3 months after SBRT and the latest time point at which any rib fracture developed was 27 months. Female gender (2.29; 95% CI: 0.98-5.20; P = 0.049), increasing BED3 Gy (1.01; 95% CI: 1.00-1.01; P = 0.016), and BED10 Gy (1.02; 95% CI: 1.01-1.04; P = 0.009) were associated with an increased probability of developing rib fractures. Increasing distance from the PTV to the chest wall was associated with a lower probability of developing rib fractures (OR: 0.69; 95% CI: 0.52-0.88; P = 0.007). Mean distance from PTV to chest wall was 2.2 cm (range: 0 - 9.5 cm). Furthermore, increasing D30cc to the chest wall (OR: 1.09; 95% CI: 1.05-1.15; P < 0.001), maximum chest wall dose (OR: 1.1; 95% CI: 1.06-1.15; P < 0.001), V40Gy (OR: 1.08; 95% CI: 1.04-1.14; P < 0.001), V30Gy (OR: 1.02; 95% CI: 1.02-1.03; P < 0.001), V20Gy (1.003; 95% CI: 1.000-1.006; P = 0.016), V10Gy (1.002; 95% CI: 1.000-1.004; P = 0.05) were associated with an increased probability of developing rib fractures. Undergoing more than one course of SBRT to the liver (P = 0.34), PTV volume (P = 0.55), mean chest wall dose (P = 0.94), left versus right side tumors (P = 0.69) and BMI > 30 (P = 0.36) were not associated with the development of rib fractures.Rib fractures after liver SBRT are a rare event and were observed in 8% of patients. Clinicians should continue to utilize well-established dose constraints and minimize radiation dose delivery to the chest wall.

Chest wall stabilization and rib fixation using a nitinol screwless system in selected patients after blunt trauma: Long-term results in a single-center experience

Abstract Objective First experience with rib fixation by use of nitinol in terms of reliability, morbidity, influence on pain control and quality of life in a large series of selected patients after blunt chest trauma. Methods Data of all patients who underwent rib fixation by use of nitinol were retrospectively analyzed in terms of indications, morbidity and in-hospital mortality. Standard clinical and radiological follow-up was performed at 1, 3, 6, 12 months after discharge. Short-, mid- and long-term pain status and health related quality of life (HRQOL) were assessed using visual analogous scale (VAS) and short form 12 (SF-12) questionnaire. Results From September 2017 until April 2019, 70 patients underwent rib fixation by use of the nitinol device, consisting of dislocated and painful fractures (67.1%), pseudarthrosis (15.7%), emergencies with hemodynamical instability (8.6%), and flail chest (8.6%). Morbidity was 21.4% without wound infection; in-hospital mortality was 2.9%. Fracture of the material occurred in 5.7% of the patients during the first year but removal of the material was not necessary. Analysis of the pain score showed a decrease of the pain with a statistical significance for the whole collective and in the group with series of dislocated fractures (p &amp;lt; 0.001, linear mixed-effects models). Assessment of HRQOL revealed a significant improvement of the physical and mental score for the mid- and long-term analysis. Conclusion Our results suggest that rib fixation with nitinol device is reliable, associated with an acceptable morbidity, and significantly decreases pain and improves health related quality of life.

Re-Irradiation with Conformal Electron Beam Therapy for Recurrent Breast Cancer

Patients with recurrent breast cancer involving the chest wall, who have been previously irradiated, present a clinical challenge. Pulsed reduced dose rate external beam radiotherapy has been shown to reduce recurrences with an acceptable rate of toxicity including chest wall soft tissue and rib necrosis [1]. For patients presenting with a breast cancer recurrence in close proximity to the skin surface, our treatment center has modified the technique by using electrons passing through customized wax bolus milled by a commercial compensator manufacturer (decimal, Sanford, FL).

Pass design and thermal analysis of high thermal resistance multi-row sintered bricks

In the thermal analysis, a numerical calculation method to verify the steady heat transfer coefficient of multi-row bricks was obtained. The effects of thermal conductivity, the number of rows and holes, the ratio of transverse wall area to wall rib area were analyzed with a view to finishing the optimal pass design for the 240 thick high thermal resistance of multi-row bricks. And the influence laws of heat transfer change of multi-row bricks were probed both in the steady state and unsteady state.

Cardiothoracic Contrecoup and Contralateral Injuries: Nomenclature, Mechanism, and Significance

Objective: Contrecoup injuries are well-known lesions in the neurosurgical practice, while their existence in other medical disciplines is lacking. Another term of confusion is the contralateral lesion that is ill defined when compared to the contrecoup injury. A nomenclature, mechanism, and clinical significance of such lesions in cardiothoracic trauma patients are warranted. Patients and Methods: Only one patient with thoracic contracoup injuries was found in a retrospective review of 477 patients with significant cardiothoracic trauma managed during a 10-year period, between January 1988 and December 1997, at Sahlgrenska University Hospital/Ostra, Gothenburg, Sweden. The other four cases with contrecoup injuries were encountered in a prospective manner in different places both in Sweden and Norway. All the four prospective cases were witnessed and well documented during trauma occurrence and management. Results: All patients developed significant contralateral chest wall symptoms and signs requiring treatment. One patient developed huge contrecoup pneumothorax. Two patients developed contrecoup hemothoraces. One patient developed contrecoup cardiac injury. One patient developed contralateral chest wall rib fractures. Two patients developed contralateral sternal fractures; one of them was unstable and required surgical fixation. Conclusions: Nomenclatures to what are have called contrecoup and contralateral lesions in cardiothoracic practice are suggested. Discrepancy between the trauma side of the chest and the resulting lesions exactly on the contralateral part may make the diagnosis difficult to understand and could give a suspicion concerning the trauma site, and whether the patient was conscious or simply not telling the truth as in case of trauma with medicolegal aspects.

System dynamics model of the support-surrounding rock system in fully mechanized mining with large mining height face and its application

Fully mechanized mining with large mining height (FMMLMH) is widely used in thick coal seam mining face for its higher recovery ratio, especially where the thickness is less than 7.0m. However, because of the great mining height and intense rock pressure, the coal wall rib spalling, roof falling and the instability of support occur more likely in FMMLMH working face, and the above three types of disasters interact with each other with complicated relationships. In order to get the relationship between each two of coal wall, roof, floor and support, and reduce the occurrence probability of the three types of disasters, we established the system dynamics (SD) model of the support-surrounding rock system which is composed of “coal wall-roof-floor-support” (CW-R-F-S) in a FMMLMH working face based on the condition of No. 15104 working face in Sijiazhuang coal mine. With the software of Vensim, we also simulated the interaction process between each two factors of roof, floor, coal wall and the support. The results show that the SD model of “CW-R-F-S” system can reveal the complicated and interactive relationship clearly between the support and surrounding rock in the FMMLMH working face. By increasing the advancing speed of working face, the support resistance or the length of support guard, or by decreasing the tip-to-face distance, the stability of “CW-R-F-S” system will be higher and the happening probability of the disasters such as coal wall rib spalling, roof falling or the instability of support will be lower. These research findings have been testified in field application in No. 15104 working face, which can provide a new approach for researching the interaction relationship of support and surrounding rock.

Grinding Machine Column Structure Dynamic Optimization

Static and dynamic characteristics of grinding machine column structure experientially designed are studied based on finite element models. Then propose structure modifications, analyze characteristics, and select the better one. Study the natural frequency changes in the sensitivity of the wall thickness and rib thickness, and determine the parameters to be optimized. Expert Design software is used to finish experimental design of the parameters, and establish the second-order response surface model. So far a multi-objective optimization model is set up easily. Here using the corresponding ideal point method with relative squared weighting method transforms it into a single - objective one. Some optimal design schemes are received by changing the weight coefficients. ANSYS simulation demonstrates that the result of optimized design is satisfied and the design method is suitable.

Stereotactic body radiation therapy for early-stage non-small-cell lung cancer utilizing a helical intensity modulated image-guided approach.

e17524 Background: To report the techniques and results of a large cohort of patients treated with stereotactic body radiotherapy (SBRT) for early-stage non-small-cell lung cancer (NSCLC) using image-guided helical intensity modulated radiation therapy (IMRT) and FDG-PET assisted targeting. Methods: Between February 2005 and August 2010, 79 patients with stage 1 NSCLC were treated with SBRT. 59 patients had T1 tumors and 20 patients had T2 tumors. 62 patients had biopsy proven malignancies and 17 patients were treated empirically based on strong clinical indications. Central tumor location did not disqualify patients. All patients underwent FDG-PET or FDG-PET/CT scanning in the treatment position for planned fusion with a separate kilovoltage (KV) CT simulation. Rigid immobilization was achieved during CT simulation using a double vacuum cast device with abdominal compression. SBRT was delivered via 12 Gy x 4 or 12 Gy x 5 fractionation scheme (48-60 Gy total). Megavoltage CT images were obtained on the treatment unit prior to therapy and repeated mid-fraction with comparison to the KV CT simulation planning images to assure set-up accuracy. Serial follow-up with FDG-PET or FDG-PET/CT studies were performed at 3 months and every 6 months thereafter on all surviving patients. Results: Median patient age was 73 years. Mean tumor size was 2.3 cm (range 0.5 – 6 cm). Median follow-up was 24 months (range 4-78 months). Overall local control rate (LCR) was 94% (95% confidence interval (CI), 86-97%) based on serial FDG-PET. LCR for T1 tumors was 95% vs. 90% for T2 tumors (p = 0.60). Entire cohort overall survival rate (OSR) was 87% (CI, 78-93%) at 1 year and 58% (CI, 47-68%) at 3 years. T1 patients had a 3-year OSR of 71% vs. 43% OSR for T2 patients (p = 0.04). No patients developed life threatening radiation pneumonitis or pulmonary complications. Chest wall pain or rib fracture was reported in 8 patients (10%; CI, 5-19%). Conclusions: Image-guided SBRT with helical IMRT delivered in 4 or 5 fractions of 12 Gy with rigid immobilization and FDG-PET assisted targeting is an effective treatment for early NSCLC and is associated with excellent local control rates and acceptable treatment-related morbidity.

Chest Wall Kinematics during Speech Breathing in Tracheoesophageal Speakers

The purpose of the present study was to determine how tracheoesophageal (TE) speakers manipulate the chest wall (rib cage and abdomen) to speak and how respiratory compromise (chronic obstructive pulmonary disease; COPD) and task variables influence those behaviors. The chest wall movements of 11 male TE speakers (5 with COPD and 6 without COPD) were measured during tidal breathing, spontaneous speech, and reading. Repeated-measures multivariate analyses were used to compare breathing behaviors across speech tasks and by respiratory health. Additional repeated-measures multivariate analyses and 1-way analyses of variance were conducted on temporal, aerodynamic, and linguistic measures. There was a significant main effect of task and a significant interaction effect of COPD and task on chest wall movements. Rib cage movements varied by task, whereas abdominal movements were as predicted. There was a significant difference in utterance length by task. There were no main effects of COPD on the chest wall and no significant group differences in utterance length, aerodynamic measures, or intelligibility. The TE speakers were generally accurate in inspiring at appropriate linguistic boundaries. The results suggest that there is robust control for speech breathing following laryngectomy, but that there is also increased effort within the chest wall. Implications for future research considerations are discussed.

805 側壁リブを用いた熱伝達促進手法についての研究(GS-5・6 伝熱促進)

805 側壁リブを用いた熱伝達促進手法についての研究(GS-5・6 伝熱促進)

Chest wall kinematics in young subjects with Pectus excavatum

Quantifying chest wall kinematics and rib cage distortion during ventilatory effort in subjects with Pectus excavatum (PE) has yet to be defined. We studied 24 patients: 19 during maximal voluntary ventilation (MVV) and 5 during MVV and cycling exercise (CE). By optoelectronic plethysmography (OEP) we assessed operational volumes in upper rib cage, lower rib cage and abdomen. Ten age-matched healthy subjects served as controls. Patients exhibited mild restrictive lung defect. During MVV end-inspiratory and end-expiratory volumes of chest wall compartments increased progressively in controls, whereas most patients avoided dynamic hyperinflation by setting operational volumes at values lower than controls. Mild rib cage distortion was found in three patients at rest, but neither in patients nor in controls did MVV or CE consistently affect coordinated motion of the rib cage. Rib cage displacement was not correlated with a CT-scan severity index. Conclusions, mild rib cage distortion rarely occurs in PE patients with mild restrictive defect. OEP contributes to clinical evaluation of PE patients.

Research on Cooling Effect with Cooling Groove Structure Parameters of Liquid Rocket Engine Thrust Chamber

To study the effects of wall thickness, rib height and groove width on cooling effect and pressure drop, three dimensional heat transfer of liquid propellant rocket engine with cooling groove is numerically investigated using gas-solid-liquid coupled heat transfer model. The one-dimensional model is adopted to describe the coolant flow and 3D heat transfer model is used to calculate the coupling heat transfer through the wall. In this text, wall thickness, rib height and groove width varied while the groove number is fixed and coolant mass flow rate remains constant. When liner material is QZr0.2 alloy, we find the optimal design point of the aspect ratio. Moreover, a fitting function of the optimal aspect ratio is acquired. The biggest error of the fitting function is 3.3% compared with numerical results.

Mechanics of rib spalling of high coal walls under fully-mechanized mining

In order to solve the problem of rib spalling of high coal walls in fully-mechanized (HCWFM) mines, we used the principle of damage mechanics to analyze coal wall rib spalling. The results show that coal wall rib spalling is, to a certain degree, a macro-performance of the development of micro-cracks. We built a mechanical model to simulate the damage to the front of coal walls, carried out theoretical calculations of the damage parameters, analyzed the effect of mining height, original cracks, seam strength, horizontal stress, vertical displacement of the coal walls and other parameters on coal wall rib spalling, which conform well with the results of our field measurements and numerical simulation. The key to control coal wall rib spalling is to control the development of cracks in coal walls. Accelerating the speed of advancing the working face, improving the setting load of support and the horizontal force of the guard board, strengthening coal walls and other technical measures can effectively reduce the degree of damage to the coal walls and control coal wall rib spalling at HCWFM faces.

Regional chest wall impedance during nonrespiratory maneuvers

To assess changes in total and regional chest wall properties during nonrespiratory maneuvers, we measured electromyographic activity of various chest wall muscles, esophageal pressure, and rib cage and abdominal surface displacements in six subjects before and during various static tasks. Subjects were seated at functional residual capacity, and quasi-sinusoidal forcing at the mouth (0.4 Hz, 500 ml) was imposed during the maneuver in the absence of active breathing. Magnitude of total chest wall impedance (magnitude of Zw) increased with effort during all maneuvers; changes in phase were small. Maneuvers involving primarily muscles of the neck and rib cage--holding a 10-kg weight, 10 kg of isometric tension between the arms, and isometric neck flexion--roughly doubled the magnitude of rib cage impedance (magnitude of Zrc) and, to a lesser degree, increased magnitude of diaphragm-abdomen impedance (magnitude of Zd-a). Unilateral and bilateral leg lifts, in addition to increasing magnitude of Zd-a, increased magnitude of Zrc. Passive 90 degrees rotation of the torso caused approximately 25% increases in magnitude of Zrc and magnitude of Zd-a; if the rotation was actively maintained by the trunk muscles, both regional impedances increased over 100%. Increases in magnitude of regional impedance were correlated to increases in regional electromyographic activity; changes in phase were small. Passive restriction of rib cage displacement by strapping increased magnitude of Zrc and magnitude of Zw but not magnitude of Zd-a, whereas abdominal strapping increased magnitude of Zd-a but did not affect magnitude of Zrc or magnitude of Zw.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory cross-sectional area-flux measurements of the human chest wall

A new device that utilizes the voltages induced in separate coils encircling the rib cage and abdomen by a magnetic field is described for measurement of cross-sectional areas of the human chest wall (rib cage and abdomen) and their variation during breathing. A uniform magnetic field (1.4 X 10(-7) Tesla at 100 kHz) is produced by generating an alternating current at 100 kHz in two square coils, 1.98 m on each side, parallel to the planes of the areas to be measured and placed symmetrically cephalad and caudad to these planes at a mean distance of 0.53 m. We demonstrated that the accuracy of the device on well-defined surfaces (squares, circles, rectangles, ellipses) was within 1% in all cases. Observed errors are due primarily to small inhomogeneities of the magnetic field and variation of the orientation of the coil relative to the field. Using a second magnetic field (80 kHz) perpendicular to the first, we measured the errors due to nonparallel orientation during quiet breathing and inspiratory capacity maneuvers. In 10 normal subjects, orientation effects were less than 2% for the rib cage and less than 0.7% for the abdomen. In five of these subjects, orientation effects at functional residual capacity in lateral and seated postures were generally less than or equal to 5%, but estimated tidal volume during spontaneous breathing was comparable to measurements in the supine posture. In five curarized patients, we assessed the linearity of volume-motion relationships of the rib cage and abdomen, comparing cross-sectional area and circumference measurements. Departures from linearity using cross-sectional areas were only one-third of those using circumferences. In seven normal subjects we compared cross-sectional area measurements with respiratory inductive plethysmography (RIP) and found comparable estimates of lung volume change over a wide range of relative rib cage contributions to tidal volume (-5 to 105%), with slightly higher standard deviations for the RIP (SD = 10% for RIP; SD = 4% for cross-sectional area).