Body Surface Area Calculation Research Articles

A comparative study of dosage strategies in HIPEC: BSA-based vs fixed dose methods.

832 Background: Peritoneal metastases commonly occur in ovarian, gastric, and colorectal cancers, significantly contributing to patient morbidity and mortality. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is a promising approach for managing peritoneal surface cancers. This procedure involves cytoreductive surgery to remove visible tumors, followed by the perfusion of heated chemotherapy (41-42°C) directly into the peritoneal cavity. HIPEC addresses the limitation of systemic chemotherapy, which often fails to penetrate the peritoneal cavity effectively. HIPEC dosing may either be a flat-fixed dose or be calculated based on Body Surface Area (BSA). BSA can be determined using three methods: actual BSA (based on weight and height), ideal BSA (based on sex and height), and adjusted BSA (considering lean and fat mass). Methods: A retrospective chart review was conducted on 151 metastatic cancer patients at UVMMC. Patient BMI, weight, and height at diagnosis were collected to calculate BSA values (actual, adjusted, and ideal) for estimating a hypothetical chemotherapy dosage. Statistical analysis using SPSS involved linear mixed models and paired t-tests to compare Mitomycin-C dosages between a fixed dose (40 mg) and a BSA-derived dose (30 mg/m²). Results: The average dosage of Mitomycin-C differed significantly depending on whether the dose was calculated using actual, adjusted, or ideal BSA. The largest discrepancy in dosage was observed between the actual BSA method and the flat-fixed dose, with an average difference of 16 mg. The smallest difference in dose was between the adjusted and ideal BSA methods. When stratifying by BMI, the greatest variation in Mitomycin-C dosage was found among overweight and obese patients (BMI ≥ 25). For these patients, the average dosage difference between the flat fixed dose and the actual BSA dose was 20 mg. In comparison, in patients with a BMI under 18.5 (underweight) the actual BSA dose was comparable to the fixed dose. Conclusions: Different institutions utilize a variety of dosing strategies for the HIPEC procedure. Differences in BSA calculation methods and perfusate volumes (literature values of 2, 3 and 4 L is most common) contribute to the complexity of establishing standardized dosing. The significant dosing variations observed, especially in overweight and obese patients, are of concern, as 70% of the U.S. population has a BMI ≥ 25. Our study demonstrates significant variability in HIPEC chemotherapy dosing, especially among patients with higher BMI. The discrepancy between BSA-based methods and flat-fixed doses may impact treatment efficacy and toxicity. Standardizing dosing approaches is important to ensure consistent therapeutic outcomes and patient safety.

An improvement of body surface area formulas using the 3D scanning technique.

Body surface area (BSA) is one of the major parameters used in several medical fields. However, there are concerns raised about its usefulness, mostly due to the ambiguity of its estimation. Authors have conducted a voluntary study to investigate BSA distribution and estimation in a group of 179 adult people of various sex, age, and physique. Here, there is provided an extended analysis of the majority of known BSA formulas. Furthermore, it was supplement with a comparison with the authors' propositions of enhanced formulas coefficients for known formulas models as well as with new power models based on an increased number of anthropometric data. Introduction of the enhanced formulas coefficients cause a reduction of at least 30.5% in mean absolute error and 21.1% in maximum error in comparison with their known counterparts. In the context of the analysis presented it can be stated that the development of a single universal body surface area formula, based on a small number of state variables, is not possible. Therefore, it is necessary and justified to search for new estimation models that allow for quick and accurate calculation of body surface area for the entire population, regardless of individual body variations. The new formulas presented are such an alternative, which achieves better results than the previously known methods. Int J Occup Med Environ Health. 2024;37(2):205-19.

BODY SURFACE AREA AND USAGE AREAS

Body surface area is an anthropometric parameter used in many areas like drug dose adjustment, burn treatment, and determination of fluid requirement, as well as to calculate the basal metabolic rate. It is critical for many medical specialties, such as chemotherapy, transplantology, burn therapy, and toxicology. Until the 19th century, researchers looked for easy ways to calculate body surface area and developed various formulas. There were several different formulas derived from height and weight measurements to predict body surface area. Historically, the DuBois & DuBois formula is the most used, but Mosteller's formula is more popular due to its simplicity. The accuracy of the body surface area formulas, which are still in use today, is still being debated because they are determined by a few sample studies, and different sizes such as children and adults are not taken into consideration in sample selection. New and practical calculation methods are tried to be determined. This review aims to investigate the emergence of the body surface area and where it is used.

Calculation of body surface area of corn snakes (Pantherophis guttatus) utilizing computed tomography.

To determine the K-constant for body surface area calculation from body weight in corn snakes (Pantherophis guttatus) through the use of computed tomography (CT) measurements. 12 adult corn snakes held by North Carolina State University for research purposes underwent CT between November 2022 and January 2023. Each snake had a CT scan, physical examination, and body weight measurement. CT images were uploaded into software able to perform 3-D reconstruction and measure body surface area. The species-specific K-constant was determined using nonlinear regression analysis between body surface area and (body weight in grams)2/3. The mean body weight of the 12 adult corn snakes was 228 g, with a mean body surface area of 505.1 cm2. The calculated K-constant was 13.6 (P < .001). The resulting formula for body surface area in corn snakes is BSA in cm2 = 13.6 X (body weight in grams)2/3. The body surface area formula developed for corn snakes will allow for improved dosing accuracy for medications with low therapeutic safety margins. Additional pharmacokinetic and pharmacodynamic studies are necessary to determine the safety and efficacy of individual medications.

Abstract 16148: Calculating Indexed Aortic Root Diameters With Ideal Body Weight Leads to Significant Reclassification in Overweight and Obese Patients

Introduction: Indexed Aortic root diameter (AoR diam) measured by transthoracic echocardiography (TTE) using body surface area (BSA) is important in children, adolescents, and small adults in whom non-indexed values may under detect dilation. However, indexed AoR diam may lead to misleading results in obese individuals as the AoR diam does not increase in proportion to body weight. Hypothesis: We hypothesize that using ideal body weight (IBW, using the Devine formula) in place of actual weight in BSA calculation reclassifies a significant proportion of indexed AoR diam in overweight and obese patients. Methods: We performed a retrospective review of all patients with a TTE at Tufts Medical Center in 2022 and Ao root diam &gt;4 cm for men and &gt;3.6 cm for women. We excluded patients &lt; 20 years old and those with inadequate TTE images or missing aortic measurements. TTE data and baseline characteristics were recorded. Indexed AoR diam was calculated using both actual and ideal body weights. The thresholds for for mildly, moderately, and severely dilated indexed AoR were ≥2.2, ≥2.4, and ≥2.6 in men, and ≥2.3, ≥2.4, and ≥2.6 in women, respectively. Results: 456 patients (400 males, 56 females) met our inclusion criteria, with a subset of 331 patients (72.6%) with BMI ≥25. When ideal body weight was used for indexing AoR diam, 58.7% of patients initially classified as having 'normal' indexed AoR diam were reclassified as at least 'mildly dilated' (p&lt;0.001). Patients with a BMI ≥25 were more often reclassified as at least ‘mildly dilated’ compared to those with lower BMI (64.6% vs. 13.3%, p&lt;0.001). In stratified analysis, upward reclassification occurred in 31.9% of patients with 'mildly dilated' AoR diam (45.8% in BMI ≥25) and 35.2% of patients with 'moderately dilated' AoR diam (80% in BMI ≥25). Conclusions: The use of ideal body weight instead of actual body weight for indexing AoR diam changes risk-stratification in over half of the patients with an abnormal AoR. This is more pronounced in patients with a BMI ≥25 and may have significant management implications. Further studies are needed to investigate if the use of actual weight in Ao root indexing systematically underestimates Ao root dilation in overweight and obese patients and if the use of IBW can improve risk assessment.

Характеристика физического и биологического развития мальчиков в Республике Тыва

Abstract. Relevance. Preserving the health of the younger generation of indigenous and small peoples of Siberia is a priority social task. Goal of research. To identify the characteristics of growth and puberty of school boys of the titular nationality in the Republic of Tyva. Material and methods. A survey of boys and young men studying in educational institutions of Kyzyl was carried out. A total of 554 students aged from 11 to 18 years old were examined. The survey included somatometry (body length and weight, chest circumference), calculation of body surface area using the Dubua formula; assessment of sexual development by J. Tanner and M.V. Maximova. Results. The dynamics of indicators of the main somatometric indicators indicates that the pubertal growth spurt occurs at the age from 13 to 15 years. The initiation of sexual development by all signs is observed in the surveyed schoolchildren from the age of 12, with an average body surface area of 1.24 m2. The average age of pubic hair onset was 13.9 ± 0.5 years; voice mutations - 14.9 ± 0.4 years; growth of the thyroid cartilage - 14.8 ± 0.5 years, respectively. Facial hair growth appears on average at the age of 15.0 ± 0.3 years and is ahead of the appearance of hair growth in the armpits (15.4 ± 0.5 years). The correspondence of the level of sexual development to the passport age was noted in 65.5% ± 2.6% of the surveyed schoolchildren. Among the disharmonious variants of biological development, delayed puberty prevailed: in 29.2 ± 2.5% of students. Conclusion. Currently, schoolchildren of the indigenous population of Tyva have a number of biological development features that can adversely affect the implementation of reproductive function.

A novel online survey approach designed to measure consumer sunscreen application thickness—implications for estimating environmental emissions

BackgroundThe effects of ultraviolet (UV) filters in the aquatic environment have been well studied, but environmental exposures remain unclear and understudied. Consumer usage directly influences the amount of sunscreen products, and subsequently UV filters, potentially released into the environment.ObjectiveTo conduct a literature review of previous research into sunscreen application thickness, develop a questionnaire protocol designed to semi-quantify sunscreen usage by US consumers, and conduct a large-scale survey to determine a sunscreen application thickness (to face and body) that is more refined than conservative defaults. The United States Food & Drug Administration (US FDA) recommends a sunscreen application rate of 2 mg/cm2. This value is typically used as a worst-case assumption in environmental exposure assessments of UV filters.MethodsDesigned a novel approach to estimate lotion sunscreen application thickness using an online questionnaire protocol employing visual references and self-reported height and weight of the respondents. A literature review was also conducted to collect historical sunscreen usage.ResultsOver 9000 people were surveyed in the US, and after the dataset was refined, their sunscreen application thickness was estimated based on calculated body surface area and reported sunscreen amounts. The mean and median values for survey respondents are 3.00 and 1.78 mg/cm2, respectively, for facial application thickness and 1.52 and 1.35 mg/cm2, respectively, for body application thickness. Earlier research from 1985–2020 reported 36 of the 38 values are below the US FDA’s recommended application thickness of 2 mg/cm2 (range 0.2–5 mg/cm2).Impact statementThis web-based survey is the first of its kind, designed specifically to quantify sunscreen application in a large and diverse set of consumers. This method provides a greater reach to larger populations thus enabling more granular data analysis and understanding. Exposure assessments of sunscreen ingredients typically use conservative parameters. These data can refine those assessments and allow for more informed and science-based risk management decisions.

Limitations of U25 CKiD and CKD-EPI eGFR formulae in patients 2-20 years of age with measured GFR > 60 mL/min/1.73 m2-a cross-sectional study.

When applying Pierce U25 formula for estimating glomerular filtration rate (eGFR), we observed a higher proportion of eGFR < 90 mL/min/1.73 m2 (chronic kidney disease (CKD) stage 2). We compared agreement and accuracy of the Pierce U25 (ages 2-25), Pottel (ages 2-100), and CKD-EPI (ages 18-100) formulae to GFR measurements. Post hoc analysis of the three eGFRs compared to 367 99m technetium-diethylene-triamine penta-acetic acid (99Tc DTPA) GFR measurements (240 patients) using 3 sampling points and Brockner/Mørtensen correction (body surface area calculation based on ideal weight) on simultaneous serum creatinine and cystatin C measurements. Overall, the U25 formula performed well with a Spearman r of 0.8102 (95% confidence interval 0.7706 to 0.8435, p < 0.0001) while diagnostic accuracy was low in patients with normal mGFR. The U25 formula reclassified 29.5% of patients with normal mGFR as CKD stage 2; whereas the average of the modified Schwartz formula based on serum creatinine and the Filler formula based on cystatin C, only over-diagnosed CKD stage 2 in 8.5%, 24.5% within 10% and 62.7% within 30%. We therefore combined both. The average Schwartz/Filler eGFR had 36.5% of results within 10%, 84.7% within 30%, and normal mGFR accuracy was 26.8%, 63.9% for 10% and 30%, respectively, outperforming the CKD-EPI and Pottel formulae. The Pierce U25 formula results correlated well with mGFR < 75 mL/min/1.73 m2. Over the entire GFR range, accuracy was better for patients with a higher mGFR, when averaging the combined Schwartz/Filler formulae. More work is needed to prospectively confirm our findings in other centers.

Defining a species-specific K constant in American Bullfrogs (Lithobates catesbeianus) through use of computed tomography.

To use CT measurements to define the body surface area (BSA) formula in American bullfrogs (Lithobates catesbeianus) and calculate the species-specific shape constant (K) to suggest chemotherapeutic doses. 12 American bullfrogs owned by the North Carolina State College of Veterinary Medicine Department of Laboratory Animal Resources underwent CT scans without anesthesia or sedation in November 2022. As part of this prospective study, each American bullfrog underwent a complete physical exam and CT scan. 3-D surface models were created using CT data, and the resulting measurements were used for BSA calculations. Animals were grouped by sex. Nonlinear regression analysis of BSA versus body weight was performed, and a species-specific formula was derived for calculating BSA in American bullfrogs. The mean body weight of the bullfrogs was 354 grams. The mean CT-derived BSA was 414.92 cm2. The calculated K constant was 8.28 for the 12 American bullfrogs, and the CT-derived BSA formula was BSA in cm2 = 8.28 X (body weight in g)2/3. The K constant was 8.07 for females and 8.44 for males and was not significantly different between sexes (P = .5). Results indicated that the species-specific K constant for American bullfrogs is 8.28. This is the first calculated K constant that exists for amphibians to our knowledge.

The impact of echocardiographic indexation to evaluate cardiac reverse remodeling throughout pregnancy and postpartum

Introduction and objectivesEchocardiography guidelines suggest normalizing left ventricular (LV) volumes and mass (LVM) to body size. During pregnancy, continuous weight variation impacts on body surface area (BSA) calculation, limiting the longitudinal analysis of cardiac remodeling (CR) and reverse remodeling (RR) variables. Our aim was to identify the most common indexing methodologies in the literature on pregnant populations through a systematic review; and, to compare four scaling methods: (i) none (absolute values); (ii) indexing to the BSA before pregnancy; (iii) allomeric indexing; and (iv) indexing to BSA measured at the same day of cardiac assessment, using an illustrative example. MethodsWe performed a systematic review of CR and RR during pregnancy and post-partum, using two databases. We included studies reporting longitudinal echocardiographic analysis of cardiac chamber volumes in humans. We used a prospective cohort study of healthy pregnant women who underwent four echocardiographic evaluations during pregnancy and postpartum, as an illustrative example. ResultsTwenty-seven studies were included, most studies indexed to BSA measured at each evaluation moment (n=21). Within-subjects design was the most reported to analyse longitudinal data (n=17). Indexation to the pre-pregnancy BSA or application of allometric indexes revealed a higher effect than BSA measured at each evaluation and an equal effect to not indexing using within-subjects design. The within-subjects designs also revealed a higher effect size value than the between-subjects design for longitudinal analysis of LVM adaptations during pregnancy and postpartum. Conclusion(s)This study concludes that indexation methods do not impact the clinical interpretation of longitudinal echocardiographic assessment but highlights the need to harmonize normalization procedures during pregnancy.

Reevaluation Body Weight and Age with Standardized Uptake Value in the Liver Cancer for [18F] FDG PET/CT

Standardized uptake values, often known as SUVs, are frequently utilized in the process of measuring 18F-fluorodeoxyglucose (FDG) uptake in malignancies . In this work, we investigated the relationships between a wide range of parameters and the standardized uptake values (SUV) found in the liver. Examinations with 18F-FDG PET/CT were performed on a total of 59 patients who were suffering from liver cancer. We determined the SUV in the liver of patients who had a normal BMI (between 18.5 and 24.9) and a high BMI (above 30) obese. After adjusting each SUV based on the results of the body mass index (BMI) and body surface area (BSA) calculations, which were determined for each patient based on their height and weight. Under a variety of different circumstances, SUVs were evaluated based on their means and standard deviations. Scatterplots were created to illustrate the various weight and SUV variances. In addition to that, the SUVs that are appropriate for each age group were determined. SUVmax in the liver was statistical significantly in obese BMI and higher BSA, p- value &lt;0.001). Age appeared to be the most important predictor of SUVmax and was significantly associated with the liver SUVmax with mean value (58.93±13.57). Conclusions: Age is a factor that contributes to variations in the SUVs of the liver. These age-related disparities in SUV have been elucidated as a result of our findings, which may help clinicians in doing more accurate assessments of malignancies. However, the SUV overestimates the metabolic activity of each and every individual, and this overestimation is far more severe in people who are obese compared to people who have a body mass index that is normal (BMI).&#x0D; &#x0D;

PO-01-014 IMPACT OF GENDER ON P- AND R-WAVE AMPLITUDE IN A SURFACE EKG SIMULATION STUDY FOR INSERTABLE CARDIAC MONITOR

Cosmetic concerns or anatomic differences between males and females may influence implantation location of Insertable Cardiac Monitor (ICM). To assess device, implant and patient factors impacting electrogram sensing by proxy of precordial single-lead surface EKG recordings. 150 participants each had 12 separate tracings of single-lead surface EKG acquired using Northeast Holter (DR200/HE) placed at the parasternal 4th intercostal space to mimic ICM recordings. 3M electrodes were positioned at different vector length (75mm & 45mm) for each of three vector angles (vertical, oblique, horizontal) repeated in two postures (upright & supine). Height and weight were assessed for body surface area (BSA) calculation and impedance-based body fat percentage (BF%) was measured. All EKG strips were uploaded into DigitizeIt software for offline analysis by blinded technicians. Kruskal-Wallis test with Dunn’s multiple pairwise comparisons was performed to assess gender differences in EGM amplitudes. A total of 1,800 tracings from 150 participants [55.5% male, median age 59years (IQR 35 – 73)] were assessed. Compared to male participants, females had lower weight [73 (60 - 87) vs. 84kg (75 – 98), p<.001] but higher BF% [24.4 ± 8.8 vs. 35.2 ± 9.6%, p<.001]. There was no difference between gender for pairwise comparisons of median P-wave amplitude in each vector angle using different vector lengths (Panel A). Male participants had larger R-wave in vertical orientation for both vector lengths, but no difference for R-wave amplitude was seen for other angles (Panel B). Overall median amplitude of P-wave was 45% larger (.042 vs. .029mV, p<.001) and R-wave was 53% larger (.81 vs. .53 mV, p<.001) for vector length of 75 vs 45mm. The oblique vector angle had the largest P-wave amplitude of .038mV (.022 – .054) and R-wave of 0.76mV (0.52 – 1.08). P-wave amplitude was identical between both gender at all vector angles. Marginal differences in R-wave amplitude are noted between males and females for vertical vector only, but not with oblique or horizontal angle. Although the oblique angle had the largest P- and R-wave amplitudes, a longer sensing vector provides larger EGM amplitudes which may be important for achieving adequate electrogram sensing when ICM implant orientation is influenced by cosmetic or anatomical considerations.

Factors impacting survival after transarterial radioembolization in patients with hepatocellular carcinoma: Results from the prospective CIRT study

Transarterial radioembolization (TARE) with Yttrium-90 resin microspheres is an established treatment option for patients with hepatocellular carcinoma (HCC). However, optimising treatment application and patient selection remains challenging. We report here on the effectiveness, safety and prognostic factors, including dosing methods, associated with TARE for HCC in the prospective observational CIRT study. We analysed 422 patients with HCC enrolled between Jan 2015 and Dec 2017, with follow-up visits every 3 months for up to 24 months after first TARE. Patient characteristics and treatment-related data were collected at baseline; adverse events and time-to-event data (overall survival [OS], progression-free survival [PFS] and hepatic PFS) were collected at every 3-month follow-up visit. We used the multivariable Cox proportional hazard model and propensity score matching to identify independent prognostic factors for effectiveness outcomes. The median OS was 16.5 months, the median PFS was 6.1 months, and the median hepatic PFS was 6.7 months. Partition model dosimetry resulted in improved OS compared to body surface area calculations on multivariable analysis (hazard ratio 0.65; 95% CI 0.46-0.92; p= 0.0144), which was confirmed in the exact matching propensity score analysis (hazard ratio 0.56; 95% CI 0.35-0.89; p= 0.0136). Other independent prognostic factors for OS were ECOG-performance status >0 (p= 0.0018), presence of ascites (p= 0.0152), right-sided tumours (p= 0.0002), the presence of portal vein thrombosis (p= 0.0378) and main portal vein thrombosis (p= 0.0028), ALBI grade 2 (p= 0.0043) and 3 (p= 0.0014). Adverse events were recorded in 36.7% of patients, with 9.7% of patients experiencing grade 3 or higher adverse events. This large prospective observational dataset shows that TARE is an effective and safe treatment in patients with HCC. Using partition model dosimetry was associated with a significant improvement in survival outcomes. Transarterial radioembolization (TARE) is a form of localised radiation therapy and is a potential treatment option for primary liver cancer. We observed how TARE was used in real-life clinical practice in various European countries and if any factors predict how well the treatment performs. We found that when a more complex but personalised method to calculate the applied radiation activity was used, the patient responded better than when a more generic method was used. Furthermore, we identified that general patient health, ascites and liver function can predict outcomes after TARE. NCT02305459.

Assessment of glomerular filtration rate by formulas in obese patients: What is the best choice?

The equations routinely used to calculate the glomerular filtration rate (GFR) have not been validated in obese patients. This cross-sectional study evaluated 7 formulas used to estimate GFR, analyzing the effect of using ideal body weight (IBW) through the formula IBW = desirable BMI × (height)2, using the calculated body surface area (BSAcalc) of each patient through the Dubois and Dubois formula. Bias, accuracy, and receiver operating characteristic curve were calculated. The criterion standard was the direct measurement of GFR by 24-hour urine creatinine clearance. Forty-five obese patients were evaluated (grade I obesity 48.89%). The formula that showed greater accuracy in grade I obesity was SalazarIBW (% error = 2.30 ± 33.92), followed by Cockcroft-GaultIBW (% error = -2.84 ± 32.76). In patients with grade II and III obesity, the most accurate formula was Chronic Kidney Disease Epidemiology (CKD-EPI) (% error = 3.84 ± 41.79), followed by the Modification of Diet in Renal Disease (MDRD) formula (% error = 4 ± 38.43). When using IBW in the Cockcroft-Gault, Sobh, and Salazar formulas, the mean GFR was closer to the criterion standard and showed an increase in the Pearson correlation. Of these 3, the one with the best performance in grade II and III obesity was Cockcroft-GaultIBW (% error = 8.90 ± 42.96). The results demonstrate that in this sample, the use of IBW improved Cockcroft-Gault performance. Cockcroft-Gault BSAcalc showed lower performance when compared to Cockcroft-GaultIBW. In grade II and III obesity, CKD-EPI and MDRD showed the best accuracy.

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

Sex-specific criteria for repair should be utilized in patients undergoing aortic aneurysm repair

ObjectiveFemale patients are more likely to undergo repair of intact and ruptured abdominal aortic aneurysm (AAA) at smaller aortic diameter compared with male patients. By adjusting for inherent anatomic differences between sexes, aortic size index (ASI) and aortic height index (AHI) may provide an additional method for guiding treatment. We therefore analyzed sex-specific criteria for AAA repair using aortic diameter, ASI, and AHI. MethodsWe identified all patients who underwent AAA repair between 2003 and 2019 in the Vascular Quality Initiative database. The Dubois and Dubois formula was used to calculate body surface area; aortic diameter was divided by body surface area to calculate ASI. Aortic diameter was divided by height to calculate AHI. Cumulative distribution curves were used to plot the proportion of patients who underwent repair of ruptured aneurysm according to aortic diameter, ASI, and AHI. Multivariable logistic regression modeling was used to identify the association of female sex with perioperative mortality and any major postoperative complication. ResultsWe identified 55,647 patients, of whom 12,664 were female (20%). For both intact and rupture repair, female patients were older, less likely to undergo endovascular aneurysm repair, and more likely to have comorbid conditions. Female patients underwent repair at smaller median aortic diameter compared with male patients for intact (5.4 vs 5.5 cm; P < .001) and rupture repair (6.7 vs 7.7 cm; P < .001). However, ASI was higher in female patients for both intact (3.1 vs 2.7 cm/m2; P < .001) and rupture repair (3.8 vs 3.7 cm/m2; P < .001), whereas AHI was higher in female patients for intact repair (3.3 vs 3.1 cm/m; P < .001) but lower for rupture repair (4.1 vs 4.3 cm/m; P < .001). When analyzing the cumulative distribution of rupture repair in male patients, 12% of rupture repairs were performed at an aortic diameter below 5.5 cm. To achieve the same proportion of rupture repair in female patients, the repair diameter was only 4.9 cm. However, when ASI and AHI were used, female and male patients both reached 12% of rupture repair at an ASI of 2.7 cm/m2 and an AHI of 3.0 cm/m. ConclusionsOur study provides data to strongly support the sex-specific 5.0-cm aortic diameter threshold suggested for repair in female patients by the Society for Vascular Surgery. The high percentage of patients undergoing rupture repair below 5.5 cm in male patients and 5.0 cm in female patients highlights the need to better identify patients at risk of rupture at smaller aortic diameters.

Use of computed tomography to determine a species-specific formula for body surface area in bearded dragons (Pogona vitticeps).

To use CT-derived measurements to calculate a shape constant (K constant) and create a formula to calculate body surface area (BSA) on the basis of body weight in bearded dragons (Pogona vitticeps). 12 adult client-owned bearded dragons that underwent CT between December 4, 2019, and April 2, 2020. Each bearded dragon in this prospective cohort study underwent physical examination, body weight measurement, and CT. A 3-D surface model was then reconstructed from CT data with available software and used for BSA calculations. Animals were considered collectively and grouped by sex and age. Nonlinear regression analysis of BSA versus body weight was performed, and a species-specific formula was derived for calculating BSA in bearded dragons. Mean age, body weight, and CT-derived BSA were 2.1 years, 356 g, and 580 cm2. The calculated K constant was 11.6 (R2 = 0.994; SE = 0.275) for the 12 bearded dragons, and the CT-derived BSA formula was as follows: BSA in cm2 = 11.6 × (body weight in g)2/3. The K constant differed substantially for bearded dragons grouped by age (12.1 for younger [between 1 and ≤ 2 years of age; n = 8] vs 10.9 for older [> 2 years of age; 4] animals) but did not differ on the basis of sex. Results indicated that because the K constant for bearded dragons in the present study was larger than the preexisting K constant of 10 used for reptiles or the various K constants established for some companion mammals, doses of chemotherapeutic drugs needed to treat affected bearded dragons may be higher than previously thought.

Body Composition and Dose-limiting Toxicity in Colorectal Cancer Chemotherapy Treatment; a Systematic Review of the Literature. Could Muscle Mass be the New Body Surface Area in Chemotherapy Dosing?

Chemotherapy dosing is traditionally based on body surface area calculations; however, these calculations ignore separate tissue compartments, such as the lean body mass (LBM), which is considered a big pool of drug distribution. In our era, colorectal cancer patients undergo a plethora of computed tomography scans as part of their diagnosis, staging and monitoring, which could easily be used for body composition analysis and LBM calculation, allowing for personalised chemotherapy dosing. This systematic review aims to evaluate the effect of muscle mass on dose-limiting toxicity (DLT), among different chemotherapy regimens used in colorectal cancer patients. This review was carried out according to the PRISMA guidelines. MEDLINE and EMBASE databases were searched from 1946 to August 2019. The primary search terms were ‘sarcopenia’, ‘myopenia’, ‘chemotherapy toxicity’, ‘chemotherapy dosing’, ‘dose limiting toxicity’, ‘colorectal cancer’, ‘primary colorectal cancer’ and ‘metastatic colorectal cancer’. Outcomes of interest were – DLT and chemotoxicity related to body composition, and chemotherapy dosing on LBM. In total, 363 studies were identified, with 10 studies fulfilling the selection criteria. Seven studies were retrospective and three were prospective. Most studies used the same body composition analysis software but the chemotherapy regimens used varied. Due to marked study heterogeneity, quantitative data synthesis was not possible. Two studies described a toxicity cut-off value for 5-fluorouracil and one for oxaliplatin based on LBM. The rest of the studies showed an association between different body composition metrics and DLTs. Prospective studies are required with a larger colorectal cancer cohort, longitudinal monitoring of body composition changes during treatment, similar body composition analysis techniques, agreed cut-off values and standardised chemotherapy regimens. Incorporation of body composition analysis in the clinical setting will allow early identification of sarcopenic patients, personalised dosing based on their LBM and early optimisation of these patients undergoing chemotherapy.

The effect of a known object in a static image of a burn to improve the burn size estimation

IntroductionCurrently information regarding burn size from referring departments to burn centres varies in accuracy. Inaccurate assessment of burn size can lead to over or under treatment. Photographs of injuries may improve accuracy of assessment. We aimed to assess the accuracy of measuring burn size on a static image by including a standard object in the image. MethodsSimulated burn areas were drawn on different body parts of the model. Using an iPhone® model 5 s with an 8 megapixel camera we took photos of the marked area, and repeated them with the palm, a standard bank card and a penny in the picture. First the Du Bois formula, was used to calculate body surface area. Members of the Burns team were asked to view the photos (n = 30) and estimate the percentage of the simulated burn. ResultsWe found an overall overestimation of burn size. Small areas of the forearm were better estimated and within 1.1% of the calculated surface area, however we found no improvement when using a standard object in these images. The back areas were most overestimated ranging from 0.9%–8.9% despite all being the same sized area. ConclusionsStatic images tend to overestimate burn size despite the use of a standard object in the image.

Estimation of stature by morphometry of percutaneous tibia

Introduction: Stature estimation is an indispensable part of the identification process of human skeletal remains or body parts. Height is also fundamental to assess growth and nutrition and calculating body surface area. Studies on anthropometric measurements of lower limbs among living people have been used as an important tool by forensic anthropologists to reconstruct the living stature of unidentified skeletal remains. Aims and Objectives: The aim of the present study was to estimate the stature from percutaneous tibial length (PCTL) by formulating linear regression equations and also by using multiplication factors, which would be useful in the field of forensic anthropology. Materials and Methods: Sample size measured 350 subjects of Sri Siddhartha Medical College, Tumkur, age group ranging from 17 to 22yrs were considered for the study. Height and PCTL were measured using the standard anthropometric technique. Results: Stature was estimated from PCTL using simple regression analysis. The height of males was significantly higher than that of females. The mean height in females and males was 158.87cm and 170.88 cm respectively; and mean PCTL was 38.54cm and 33.99cm in male and female respectively which was significantly (p Conclusion: Stature can be estimated using the anthropometric measurements of tibia in an intact mutilated leg. Keywords: Height, Tibial length, Anthropometry, Regression equation.