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Macrophage aggregates (MAs) are focal accumulations of pigmented macrophages in the spleen and other tissues of fish. A central role of MAs is the clearance and destruction of degenerating cells and recycling of some cellular components. Macrophage aggregates also respond to chemical contaminants and infectious agents and may play a role in the adaptive immune response. Tissue damage or physiological stress can result in increased MA accumulation. As a result, MAs may be sensitive biomarkers of environmental stress in fish. Abundance of MAs in tissues has been reported in a variety of ways-most commonly as density, mean size, and relative area-but the utility of these estimates has not been compared. In this study, four different types of splenic MA abundance estimates (abundance score, density, relative area, and total volume) were compared in two fish populations (Striped Bass Morone saxatilis and White Perch M. americana) with a wide range in ages. Stereological estimates of total volume indicated an increase in MA abundance with spleen volume, which generally corresponded to fish age, and with splenic infections (mycobacteria or trematode parasites). Abundance scores were generally limited in the ability to detect changes in MA abundance by these factors, whereas density estimates were greatly influenced by changes in spleen volume. In some instances, densities declined while the total volume of MAs and spleen volume increased. Experimentally induced acute stress resulted in a decrease in spleen volume and an increase in MA density, although the total volume of MAs remained unchanged. Relative area estimates accounted for the size and number of MAs but not for changes in organ volume. Total volume is an absolute measure of MA abundance irrespective of changes in organ volume or patterns of accumulation and may provide an improved means of quantifying MAs in the spleens of fish.

The purpose of this case study is to develop a method to account for the difference in the daily volumes in the bladder, rectum, and targets in prostate radiotherapy and to compare the predicted dose to the actual dose to these organs. Five patients, both prospectively and retrospectively, were selected from 2 different cancer centers, with a biopsy-confirmed diagnosis of prostate cancer. The patients' planning target volume (PTV) and organs at risk (OAR) were contoured on the computed tomography (CT) dataset using either Eclipse or Monaco treatment planning systems (TPSs). Cone-beam computed tomography (CBCT) scans were collected before each daily treatment and exported to MIM software for analysis. The automatically generated reports evaluated the organ volume changes, the actual dose received during a single fraction, and the projected dose to each organ at the completion of the treatment course via comparative cumulative dose-volume histograms (DVHs). Volume changes in the bladder and rectum can cause notable variations in the prescribed dose vs the actual dose received. MIM software was proven to have utility prospectively by tabulating daily dose and projecting final doses, potentially aiding physicians in decisions about the boost plans, thus making offline adaptive radiation therapy (ART) clinically manageable.

Obesity increases significantly cancer risk in various organs. Although this has been recognized for decades, the mechanism through which this happens has never been explained. Here, we show that obese people (BMI ≥30) have on average 55% (95%CI: 46%-66%), 68% (95%CI: 59%-76%), and 39% (95%CI: 29%-49%) larger kidneys, liver, and pancreas, respectively. We also find a significant linear relationship between the increase in organ volume and the increase in cancer risk (P-value−12). These results provide a mechanism explaining why obese individuals have higher cancer risk in several organs: the larger the organ volume the more cells at risk of becoming cancerous. These findings are important for a better understanding of the effects that obesity has on cancer risk and, more generally, for the development of better preventive strategies to limit the mortality caused by obesity.

BACKGROUND The kidneys are the dose-limiting organ in lutetium-177 DOTATATE therapy. Therefore, it is advisable to perform critical organ dosimetry focussed on renal dose in treated patients. A key uncertainty in such dose estimates is the use of standard phantoms to represent the individual patient. The primary aim of this study was to investigate the accuracy of methods for estimating kidney size, and hence absorbed kidney dose, by comparison with individual measurements from computed tomography (CT) imaging. MATERIALS AND METHODS Kidney volume was measured using diagnostic CT images for 57 patients who underwent lutetium-177 DOTATATE therapy. Kidney mass was also estimated in two ways: using the standard adult phantoms, as well as through the application of a weight scaling factor to these phantoms and their organs. Dose calculations were performed for each of the three methods using OLINDA/EXM software. RESULTS Scaling of the phantom by patient weight gave a more accurate result when compared with the CT gold standard than the standard phantom. The dose difference from the CT method had mean values of 1.4% (SD=22.6%) and 8.4% (SD=21.5%) for scaled and unscaled, respectively. Patient weight was not found to be a good predictor of kidney mass in these patients (r of 0.12 from linear regression analysis). CONCLUSION The most accurate method of organ volume estimation would be individual measurements from CT imaging; however, where this is not possible, scaling of organ masses by weight ratio is more accurate than the use of the standard phantom.

Background/aims Computed tomography (CT) hepatic volumetry is currently accepted as the most reliable method for preoperative estimation of graft weight in living donor liver transplantation (LDLT). However, several factors can cause inaccuracies in CT volumetry compared to real graft weight. The purpose of this study was to determine the frequency and degree of resection plane-dependent error in CT volumetry of the right hepatic lobe in LDLT. Methods Forty-six living liver donors underwent CT before donor surgery and on postoperative day 7. Prospective CT volumetry (VP) was measured via the assumptive hepatectomy plane. Retrospective liver volume (VR) was measured using the actual plane by comparing preoperative and postoperative CT. Compared with intraoperatively measured weight (W), errors in percentage (%) VP and VR were evaluated. Plane-dependent error in VP was defined as the absolute difference between VP and VR. % plane-dependent error was defined as follows: |VP-VR|/W∙100. Results Mean VP, VR, and W were 761.9 mL, 755.0 mL, and 696.9 g. Mean and % errors in VP were 73.3 mL and 10.7%. Mean error and % error in VR were 64.4 mL and 9.3%. Mean plane-dependent error in VP was 32.4 mL. Mean % plane-dependent error was 4.7%. Plane-dependent error in VP exceeded 10% of W in approximately 10% of the subjects in our study. Conclusions There was approximately 5% plane-dependent error in liver VP on CT volumetry. Plane-dependent error in VP exceeded 10% of W in approximately 10% of LDLT donors in our study. This error should be considered, especially when CT volumetry is performed by a less experienced operator who is not well acquainted with the donor hepatectomy plane.

The study provided a simple method of using voxel count method to estimate organ volume together with x-ray attenuation coefficient principle. The aim is to discuss the role of x-ray attenuation coefficient in CT organ volume measurements using voxel count method. The method involve using the principle of linear attenuation coefficient which describes the fraction of a beam of x-rays or gamma rays that is absorbed or scattered per unit thickness of the absorber to enable tissue differentiation and hence the used of volume elements method, where the body is literally divided into 3-dimensional rectangular boxes with known size and thickness. This value basically accounts for the number of atoms within a specified distance of a material and the probability of a photon being scattered or absorbed from the nucleus or an electron of one of these atoms. A graph of linear attenuation coefficients versus radiation energy are used to separate between various body tissues. At a specific energy the difference in attenuation between two tissues is greatest at a specific radiographic contrast in an image. Hence, this variation enable a separation and subsequent measurements of varied tissues. Therefore, it is extremely useful to determine various linear attenuation coefficients of tissues to enable various variations to be determine for clinical application.

WOS: 000488851900005 PubMed: 31579893 Purpose This study aims to evaluate the effects of extracorporeal shock wave therapy applied before and/or immediately after the osteotomy on the maturation during the consolidation phase. Materials and Methods 21 female New Zealand rabbits were used in the study. Subjects were divided randomly into three groups: Control (Distraction without ESWT), A (Distraction+ESWT After Osteotomy), AB (Distraction+ESWT After and Before Osteotomy). ESWT (500 pulses, 5 Hz, 0.19 mJ/mm(2) energy flux density) was applied to group A and group AB after 5, 12 and 19 days after osteotomy and group AB only on days 7,14 and 21 before osteotomy. On the 28th day of the consolidation period, all subjects were sacrificed. Dual-energy x-ray absorptiometry (DEXA) was used to determine bone mineral density (BMD) and bone mineral content (BMC), and stereological methods were used to determine the new bone, connective tissue and neovascularization volumes. Results As a result of DEXA examinations made on the 1st and 4th week of consolidation, there was no significant difference between groups regarding BMD and BMC values. According to the results of stereological examination, when the connective tissue and new bone tissue were evaluated, higher values were observed in AB when compared to A, and in AB and A compared to the control group, but the differences are not statistically significant. There was no difference between the groups in terms of neovascularization. Conclusion ESWT in these parameters was not positively effective in bone maturation during consolidation when applied before osteotomy or both before and after osteotomy. Project Management Office Coordinatorship of Ondokuz Mayis UniversityOndokuz Mayis University [PYO. DIS.1904.12.007] This study was supported by Project Management Office Coordinatorship of Ondokuz Mayis University with PYO. DIS.1904.12.007 project code.

Purpose: To analyze the optimum organ filling point for organs at risk (OARs) dose in cervical cancer high-dose-rate (HDR) brachytherapy. Material and methods : In a retrospective study, 32 locally advanced cervical cancer patients (97 insertions) who were treated with 3D conformal external beam radiation therapy (EBRT) and concurrent chemotherapy during 2010-2013 were included. Rotterdam HDR tandem-ovoid applicators were used and computed tomography (CT) scanning was performed after each insertion. The OARs delineation and GEC-ESTRO-based clinical target volumes (CTVs) contouring was followed by 3D forward planning. Then, dose volume histogram (DVH) parameters of organs were recorded and patients were classified based on their OARs volumes, as well as their inserted tandem length. Results : The absorbed dose to point A ranged between 6.5-7.5 Gy. D 0.1cm ³ and D 2cm ³ of the bladder significantly increased with the bladder volume enlargement (p value < 0.05). By increasing the bladder volume up to about 140 cm3, the rectum dose was also increased. For the cases with bladder volumes higher than 140 cm3, the rectum dose decreased. For bladder volumes lower than 75 cm3, the sigmoid dose decreased; however, for bladder volumes higher than 75 cm3, the sigmoid dose increased. The D 2cm ³ of the bladder and rectum were higher for longer tandems than for shorter ones, respectively. The divergence of the obtained results for different tandem lengths became wider by the extension of the bladder volume. The rectum and sigmoid volume had a direct impact on increasing their D 0.1cm ³ and D 2cm ³, as well as decreasing their D 10 , D 30 , and D 50 . Conclusions : There is a relationship between the volumes of OARs and their received doses. Selecting a bladder with a volume of about 70 cm3 or less proved to be better with regards to the dose to the bladder, rectum, and sigmoid.

Background The aim of this study was to evaluate the performance of a commercial knowledge-based planning system, in volumetric modulated arc therapy for prostate cancer at multiple radiation therapy departments. Methods In each institute, > 20 cases were assessed. For the knowledge-based planning, the estimated dose (ED) based on geometric and dosimetric information of plans was generated in the model. Lower and upper limits of estimated dose were saved as dose volume histograms for each organ at risk. To verify whether the models performed correctly, KBP was compared with manual optimization planning in two cases. The relationships between the EDs in the models and the ratio of the OAR volumes overlapping volume with PTV to the whole organ volume (Voverlap/Vwhole) were investigated. Results There were no significant dosimetric differences in OARs and PTV between manual optimization planning and knowledge-based planning. In knowledge-based planning, the difference in the volume ratio of receiving 90% and 50% of the prescribed dose (V90 and V50) between institutes were more than 5.0% and 10.0%, respectively. The calculated doses with knowledge-based planning were between the upper and lower limits of ED or slightly under the lower limit of ED. The relationships between the lower limit of ED and Voverlap/Vwhole were different among the models. In the V90 and V50 for the rectum, the maximum differences between the lower limit of ED among institutes were 8.2% and 53.5% when Voverlap/Vwhole for the rectum was 10%. In the V90 and V50 for the bladder, the maximum differences of the lower limit of ED among institutes were 15.1% and 33.1% when Voverlap/Vwhole for the bladder was 10%. Conclusion Organs’ upper and lower limits of ED in the models correlated closely with the Voverlap/Vwhole. It is important to determine whether the models in KBP match a different institute’s plan design before the models can be shared.

Background/Aims Computed tomography (CT) hepatic volumetry is currently accepted as the most reliable method for preoperative estimation of graft weight in living donor liver transplantation (LDLT). However, several factors can cause inaccuracies in CT volumetry compared to real graft weight. The purpose of this study was to determine the frequency and degree of resection plane-dependent error in CT volumetry of the right hepatic lobe in LDLT. Methods Forty-six living liver donors underwent CT before donor surgery and on postoperative day 7. Prospective CT volumetry (VP) was measured via the assumptive hepatectomy plane. Retrospective liver volume (VR) was measured using the actual plane by comparing preoperative and postoperative CT. Compared with intraoperatively measured weight (W), errors in percentage (%) VP and VR were evaluated. Plane-dependent error in VP was defined as the absolute difference between VP and VR. % plane-dependent error was defined as follows: |VP–VR|/W∙100. Results Mean VP, VR, and W were 761.9 mL, 755.0 mL, and 696.9 g. Mean and % errors in VP were 73.3 mL and 10.7%. Mean error and % error in VR were 64.4 mL and 9.3%. Mean plane-dependent error in VP was 32.4 mL. Mean % plane-dependent error was 4.7%. Plane-dependent error in VP exceeded 10% of W in approximately 10% of the subjects in our study. Conclusions There was approximately 5% plane-dependent error in liver VP on CT volumetry. Plane-dependent error in VP exceeded 10% of W in approximately 10% of LDLT donors in our study. This error should be considered, especially when CT volumetry is performed by a less experienced operator who is not well acquainted with the donor hepatectomy plane.

The deformable registration of a preoperative organ volume to an intraoperative laparoscopy image is required to achieve augmented reality in laparoscopy. This is an extremely challenging objective for the liver. This is because the preoperative volume is textureless, and the liver is deformed and only partially visible in the laparoscopy image. We solve this problem by modeling the preoperative volume as a Neo-Hookean elastic model, which we evolve under shading and contour cues. The contour cues combine the organ’s silhouette and a few curvilinear anatomical landmarks. The problem is difficult because the shading cue is highly nonconvex and the contour cues give curve-level (and not point-level) correspondences. We propose a convergent alternating projections algorithm, which achieves a \(4\%\) registration error.

The objective of our study was to measure thyroid volumes using semiautomated 3D CT and to compare the 3D CT volumes with volumes measured using 2D ultrasound, 2D CT, and the water displacement method.In 47 patients, 2D ultrasound volumes and 2D CT volumes of the thyroid gland were estimated using the ellipsoid volume formula, and 3D CT volumes were calculated using semiautomated reconstructive techniques. All volume data were compared with thyroid specimen volumes obtained using the water displacement method and were statistically analyzed using the one-way ANOVA, the Pearson correlation coefficient (R), linear regression, and the concordance correlation coefficient (CCC). The processing time of semiautomated 3D CT thyroid volumetry was measured.The paired mean differences ± SD between the three imaging-determined volumes and the specimen volumes were 0.8 ± 3.1 mL for 2D ultrasound, 4.0 ± 4.7 mL for 2D CT, and 0.2 ± 2.5 mL for 3D CT. A significant difference in the mean thyroid volume was found between 2D CT and specimen volumes (p = 0.016) compared with the other pairs (p = 0.937 for 2D ultrasound mean volume vs specimen mean volume, and p = 0.999 for 3D CT mean volume vs specimen mean volume). Between specimen volume and 2D ultrasound volume, specimen volume and 2D CT volume, and specimen volume and 3D CT volume, R values were 0.885, 0.724, and 0.929, respectively, and CCC values were 0.876, 0.598, and 0.925, respectively. The mean processing time of semiautomated 3D CT thyroid volumetry was 7.0 minutes.Thyroid volumes measured using 2D ultrasound or semiautomated 3D CT are substantially close to thyroid specimen volumes measured using the water displacement method. Semiautomated 3D CT thyroid volumetry can provide a more reliable measure of thyroid volume than 2D ultrasound.

Background: The purpose of this study is to quantitatively characterize interfraction variations of lumpectomy cavity (LC) in accelerated partial breast irradiation (APBI) and their dosimetric impacts, and to explore the use of an online adaptive replanning scheme to address these variations. Methods: A total of about 100 diagnostic-quality CT sets acquired using an in-room CT at each fraction during image-guided radiation therapy (IGRT) for ten randomly-selected patients treated with APBI in the supine position were analyzed. The LC, treated breast, lung and heart were delineated on each fraction CT. Organ volume change and deformation were quantified. For each fraction CT, three types of plans were created: adaptive, repositioning, and fully re-optimized plans. The plan qualities were compared. Results: Significant changes in LC shape and volume were observed during APBI. On average, the LC volume decreases by 23% from the planning CT. The average change in LC shape, as measured by the Dice’s coefficient, is 80%. For all patients, the adaptive plans were comparable to the re-optimization plans. For small and moderate LC changes (70%), the three types of plans were comparable, indicating that the current IGRT with the standard margins was sufficient to account for the interfraction variations. For cases with extreme LC change (30%), the adaptive plans offered improved target coverage and/or normal tissue sparing as compared with the repositioning plans. Conclusions: Significant variations in the LC between planning and treatment were found for APBI. The current practice of IGRT with standard planning target volume margins can account for these variations for most cases. Online adaptive replanning was needed for cases with extremely large changes in LC.

Purpose: To investigate the efficacy of total prostate-specific antigen (tPSA) and free prostate-specific antigen (fPSA) for the estimation of prostate volume (PV) in pathologically-proven benign prostatic hyperplasia (BPH) patients. Methods: From January 2010 to March 2013, 165 Korean men with a PSA less than 10 ng/mL who were diagnosed without prostate cancer by prostate biopsy were enrolled. Patients were classified into three age groups: ≤60, 61–70, and >70 years old. The results were organized to estimate and compare the ability of serum tPSA and fPSA to assess the PV. Results: Enrolled patients had a median age of 63.5 years (44 to 80), a median tPSA of 5.72 ng/mL, a median fPSA of 0.98 ng/mL and a median PV of 53.68 mL, respectively. Among the associations between tPSA, fPSA, age, and PV, the highest correlation was verified between fPSA and PV (r=0.377, P

Purpose: Investigation of the influence of radiation dose to salivary glands on xerostomia in patients with head and neck cancers. Methods: From October 2002 to December 2011, 548 patients with head and neck carcinomas were treated in our department using intensity modulated radiotherapy (IMRT). 325 patients were eligible for analysis more than 1 year after irradiation. Xerostomia was evaluated according to the criteria of Radiation Therapy and Oncology Group (RTOG) and xerostomia related questionnaire. For statistical analysis grade 1 and 2 were recorded as mild and grade 3 and 4 as severe xerostomia. The dosimetric values for absolute mean dose, biological equivalent mean dose (EQD2), the relative organ volume not exceeding 20 Gy, 25 Gy and 30 Gy (V20, V25, V30) for all 4 major salivary glands or for both parotid glands only were used for analysis. V20 revealed the best discrimination between both patient groups (with vs. without xerostomia), compared to parameters V25 and V30. Therefore the volume of the salivary glands receiving less than 20 Gy (V 20Gy) was analyzed additionally. Mann-Whitney-U-test, Kruskal-Wallis-test and logistic regression were used in statistical analysis. Results: A TD 50 can be determined for the occurrence of xerostomia more than one year after radiotherapy for both parotid glands of 19.3 Gy for the mean dose absolute, 11.2 Gy for the mean dose EQD2, 38.2% for V20, 26.8% for V25, 18.7% for V30, 34.9 ml for V 20Gy. For all major salivary glands theses values were 25.7 Gy for the mean dose absolute, 15.6 Gy for the mean dose EQD2, 51.3% for V20, 41.1% for V25, 33.9% for V30 and 34.8 ml for V 20Gy. Conclusions: The identification of a tolerance dose for the salivary glands for treatment planning appears to be difficult, as the dose-response correlation only shows a flat slope. Additionally, a large interindividual variability seems to exist. We could not found any threshold dose for development of xerostomia.

In this study, we have developed a microfluidic device with metabolism function toward pharmacokinetic study. The device has reproduced physiological parameters such as an organ volume ratio and a blood flow ratio on a single-chip. The ratios have been reappeared by control of the area of cell culture chambers and a bypass channel, respectively. HepG2 (Liver model) and A549 (target model) have been co-cultured in each culture chambers in the device. In this paper, we performed a cell-based assay using prodrug CPT-11 that is metabolized to SN-38 by Carboxyl Esterase (CE) to examine functions of the device.

Objective To assess the accuracy of a semiautomated 3D volume reconstruction method for organ volume measurement by postmortem MRI. Methods This prospective study was approved by the institutional review board and the infants9 parents gave their consent. Postmortem MRI was performed in 16 infants (1 month to 1 year of age) at 1.5 T within 48 h of their sudden death. Virtual organ volumes were estimated using the Myrian software. Real volumes were recorded at autopsy by water displacement. The agreement between virtual and real volumes was quantified following the Bland and Altman9s method. Results There was a good agreement between virtual and real volumes for brain (mean difference: −0.03% (−13.6 to +7.1)), liver (+8.3% (−9.6 to +26.2)) and lungs (+5.5% (−26.6 to +37.6)). For kidneys, spleen and thymus, the MRI/autopsy volume ratio was close to 1 (kidney: 0.87±0.1; spleen: 0.99±0.17; thymus: 0.94±0.25), but with a less good agreement. For heart, the MRI/real volume ratio was 1.29±0.76, possibly due to the presence of residual blood within the heart. The virtual volumes of adrenal glands were significantly underestimated (p=0.04), possibly due to their very small size during the first year of life. The percentage of interobserver and intraobserver variation was lower or equal to 10%, but for thymus (15.9% and 12.6%, respectively) and adrenal glands (69% and 25.9%). Conclusions Virtual volumetry may provide significant information concerning the macroscopic features of the main organs and help pathologists in sampling organs that are more likely to yield histological findings.

The purpose of this study was to evaluate automated CT volumetry in the assessment of living-donor livers for transplant and to compare this technique with software-aided interactive volumetry and manual volumetry.Hepatic CT scans of 18 consecutively registered prospective liver donors were obtained under a liver transplant protocol. Automated liver volumetry was developed on the basis of 3D active-contour segmentation. To establish reference standard liver volumes, a radiologist manually traced the contour of the liver on each CT slice. We compared the results obtained with automated and interactive volumetry with those obtained with the reference standard for this study, manual volumetry.The average interactive liver volume was 1553 ± 343 cm(3), and the average automated liver volume was 1520 ± 378 cm(3). The average manual volume was 1486 ± 343 cm(3). Both interactive and automated volumetric results had excellent agreement with manual volumetric results (intraclass correlation coefficients, 0.96 and 0.94). The average user time for automated volumetry was 0.57 ± 0.06 min/case, whereas those for interactive and manual volumetry were 27.3 ± 4.6 and 39.4 ± 5.5 min/case, the difference being statistically significant (p0.05).Both interactive and automated volumetry are accurate for measuring liver volume with CT, but automated volumetry is substantially more efficient.

OBJETIVO: Determinar valores de referência para o volume da placenta entre 7 e 10 semanas e 6 dias de gestação por meio da ultrassonografia tridimensional utilizando o método XI VOCAL (eXtended Imaging Virtual Organ Computer-aided Analysis). MATERIAIS E MÉTODOS: Realizou-se estudo de corte transversal com 70 gestantes normais entre 7 e 10 semanas e 6 dias. Para o cálculo de volume, utilizou-se o método XI VOCAL com delimitação de dez planos adjacentes. Foram determinadas médias, medianas, desvios-padrão, valores máximo e mínimo para o volume da placenta. Para avaliar a correlação do volume da placenta com a idade gestacional, foi criado gráfico de dispersão, sendo o ajuste realizado pelo coeficiente de determinação (R²). RESULTADOS: A média do volume da placenta variou de 4,6 cm³ (2,6-8,6 cm³) a 28,9 cm³ (11,4-66,9 cm³). O volume da placenta (VP) se mostrou altamente correlacionado com a idade gestacional (IG), sendo o melhor ajuste com a regressão exponencial [VP = exp(0,582 × IG + 0,063); R² = 0,82]. CONCLUSÃO: Valores de referência para o volume da placenta no primeiro trimestre de gestação utilizando o método XI VOCAL foram determinados. OBJECTIVE: To determine reference values for placental volume at 7 to 10 + 6 weeks of gestation by means of three-dimensional ultrasonography with the XI VOCAL (eXtended Imaging Virtual Organ Computer-aided Analysis) method. MATERIALS AND METHODS: A cross-sectional study was developed with 70 pregnant women at 7 to 10 + 6 weeks of gestation. The XI VOCAL method with ten sequential adjacent planes was utilized in the volume calculations. Means, medians, standard deviation, minimum and maximum values for placental volume were calculated. A scatter plot adjusted by the determination coefficient (R²) was constructed to correlate placental volume and gestational age. RESULTS: Mean placental volume ranged from 4.6 cm³ (2.6-8.6 cm³) to 28.9 cm³ (11.4-66.9 cm³). The placental volume (PV) has shown to be highly correlated with the gestational age (GA) and the best fit equation was [PV = exp(0.582 × GA + 0.063); R² = 0.82]. CONCLUSION: Reference values for placental volume in the first gestational trimester were determined with the XI VOCAL method.

Purpose To calculate the measurement error of the hourly fetal urine production rate (HFUPR) and evaluate the implication of different methods for measuring the HFUPR, i.e. ellipsoid versus sum-of-cylinders method. Methods The calculation was based on sonographic documentation of the increased bladder volumes during the filling phase, the bladder volume measurement error and the number and time points of bladder image capture. Results The probability of a false pathological reading was excluded (0%) with the sum-of-cylinders method for gestational ages of ≥30 weeks. With the ellipsoid method, the risk was higher. The maximum changes which could be exclusively explained by measurement error were four to five times greater with the ellipsoid method compared with the sum-of-cylinders method. Conclusions The present paper illustrates a careful evaluation of the HFUPR measurement error and the implications of using different ultrasound methods for bladder volume estimations. Electronic supplementary material The online version of this article (doi:10.1007/s00404-009-1242-6) contains supplementary material, which is available to authorized users.

The purpose of our study was to evaluate the interobserver variability of transrectal ultrasound for prostate volume measurement according to the prostate volume and the level of observer experience.Endorectal sonography was performed independently by two experienced observers in 101 patients and by one experienced and one less experienced observer in 110 patients; the prostate volume was then measured using the prolate ellipsoid formula. The volume difference between observers was analyzed according to the mean measured prostate volume determined by the observers and according to the level of observer experience.The volume difference was greater in prostates with a mean measured volumeor= 30 mL than in prostates with a mean measured volume30 mL (6.00 vs 1.51 mL in the experienced observers and 6.84 vs 3.99 mL in the experienced and less experienced observers) (p0.05). The frequency of volume differences5 mL was greater in prostates with a mean measured volumeor= 30 mL than in prostates with a mean measured volume30 mL (between the experienced observers, 18% vs 1%; between the experienced and less experienced observers, 54% vs 25%) (p0.01 in both comparisons). The volume difference was greater between the experienced and less experienced observers (5.00 mL) than between the experienced observers (2.96 mL) (p = 0.01). The frequency of volume difference5 mL was greater between the experienced and less experienced observers (35%) than between the experienced observers (7%) (p0.01).Prostate volume measurement by transrectal ultrasound may vary when patients have large prostates or observers have varying levels of experience.

We developed a novel digital tomosynthesis (DTS) reconstruction method using a deformation field map to optimally estimate volumetric information in DTS images. The deformation field map is solved by using prior information, a deformation model, and new projection data. Patients’ previous cone-beam CT (CBCT) or planning CT data are used as the prior information, and the new patient volume to be reconstructed is considered as a deformation of the prior patient volume. The deformation field is solved by minimizing bending energy and maintaining new projection data fidelity using a nonlinear conjugate gradient method. The new patient DTS volume is then obtained by deforming the prior patient CBCT or CT volume according to the solution to the deformation field. This method is novel because it is the first method to combine deformable registration with limited angle image reconstruction. The method was tested in 2D cases using simulated projections of a Shepp–Logan phantom, liver, and head-and-neck patient data. The accuracy of the reconstruction was evaluated by comparing both organ volume and pixel value differences between DTS and CBCT images. In the Shepp–Logan phantom study, the reconstructed pixel signal-to-noise ratio (PSNR) for the 60° DTS image reached 34.3 dB. In the liver patient study, the relative error of the liver volume reconstructed using 60° projections was 3.4%. The reconstructed PSNR for the 60° DTS image reached 23.5 dB. In the head-and-neck patient study, the new method using 60° projections was able to reconstruct the 8.1° rotation of the bony structure with 0.0° error. The reconstructed PSNR for the 60° DTS image reached 24.2 dB. In summary, the new reconstruction method can optimally estimate the volumetric information in DTS images using 60° projections. Preliminary validation of the algorithm showed that it is both technically and clinically feasible for image guidance in radiation therapy.

Because organ motion during a radiation treatment fraction can be substantial, with resultant alterations in organ volume definition and dosimetry, interventions to reduce the impact of intratreatment organ motion are required for many patients if dose escalation and reduction of dose to normal tissue are treatment goals. Before radiation delivery, fluoroscopy, cine computed tomography scans and magnetic resonance imaging can be used to measure the magnitude of organ motion for an individual patient. Strategies to minimize organ motion caused by breathing during radiation include altering breathing patterns, treating during voluntary or controlled breath holds, gating the radiation beam or tracking it with organ motion. Here the first 2 interventions will be primarily discussed. Approaches to minimize nonrespiratory organ motion include maintaining the same preparative regimen before each treatment and ensuring comfortable immobilization and short overall treatment time.

Administered dose of ionizing radiation during medical imaging is an issue of increasing concern for the patient, for the clinical community, and for respective regulatory bodies. CT radiation dose is currently estimated based on a set of very simplifying assumptions which do not take the actual body geometry and organ specific doses into account. This makes it very difficult to accurately report imaging related administered dose and to track it for different organs over the life of the patient. In this paper this deficit is addressed in a two-fold way. In a first step, the absorbed radiation dose in each image voxel is estimated based on a Monte-Carlo simulation of X-ray absorption and scattering. In a second step, the image is segmented into tissue types with different radio sensitivity. In combination this allows to calculate the effective dose as a weighted sum of the individual organ doses. The main purpose of this paper is to assess the feasibility of automatic organ specific dose estimation. With respect to a commercially applicable solution and respective robustness and efficiency requirements, we investigated the effect of dose sampling rather than integration over the organ volume. We focused on the thoracic anatomy as the exemplary body region, imaged frequently by CT. For image segmentation we applied a set of available approaches which allowed us to cover the main thoracic radio-sensitive tissue types. We applied the dose estimation approach to 10 thoracic CT datasets and evaluated segmentation accuracy and administered dose and could show that organ specific dose estimation can be achieved.

This chapter gives an overview of some of the important advances made in abdominal and pelvic magnetic resonance imaging. The chapter focuses on four specific areas in the body that have seen major advances in the last ten years; the gastro-intestinal tract, liver, kidney, and foetus and placenta in the female pelvis. It describes some of the MRI techniques utilised to measure organ volume, understand organ physiology and structure in health and disease, and determine potential disease biomarkers.

Purpose: Measurements of internal organ motion have demonstrated that daily organ deformation exists throughout the course of radiation treatment. However, a method of constructing the resultant dose delivered to the organ volume remains a difficult challenge. In this study, a model to quantify internal organ motion and a method to construct a cumulative dose in a deforming organ are introduced. Methods and Materials: A biomechanical model of an elastic body is used to quantify patient organ motion in the process of radiation therapy. Intertreatment displacements of volume elements in an organ of interest is calculated by applying an finite element method with boundary conditions, obtained from multiple daily computed tomography (CT) measurements. Therefore, by incorporating also the measurements of daily setup error, daily dose delivered to a deforming organ can be accumulated by tracking the position of volume elements in the organ. Furthermore, distribution of patient-specific organ motion is also predicted during the early phase of treatment delivery using the daily measurements, and the cumulative dose distribution in the organ can then be estimated. This dose distribution will be updated whenever a new measurement becomes available, and used to reoptimize the ongoing treatment. Results: An integrated process to accumulate dosage in a daily deforming organ was implemented. In this process, intertreatment organ motion and setup error were systematically quantified, and incorporated in the calculation of the cumulative dose. An example of the rectal wall motion in a prostate treatment was applied to test the model. The displacements of volume elements in the rectal wall, as well as the resultant doses, were calculated. Conclusion: This study is intended to provide a systematic framework to incorporate daily patient-specific organ motion and setup error in the reconstruction of the cumulative dose distribution in an organ of interest. The realistic dose distribution in an organ of interest gives the true dose–volume relationship, and may play an important role in the evaluation of the dose response of human organs. Dose reconstruction during the course of treatment delivery can also be used as an important feedback for the online optimization of individual treatment plans.

Rationale: The spatial distribution of blood flow in the hearts of genetically modified mice is a phenotype of interest because derangements in blood flow may precede detectable changes in organ function. However, quantifying the regional distribution of blood flow within organs of mice is challenging because of the small organ volume and the high resolution required to observe spatial differences in flow. Traditional microsphere methods in which the numbers of microspheres per region are indirectly estimated from radioactive counts or extracted fluorescence have been limited to larger organs for 2 reasons; to ensure statistical confidence in the measured flow per region and to be able to physically dissect the organ to acquire spatial information. Objective: To develop methods to quantify and statistically compare the spatial distribution of blood flow within organs of mice. Methods and Results: We developed and validated statistical methods to compare blood flow between regions and with the same regions over time using 15-µm fluorescent microspheres. We then tested this approach by injecting fluorescent microspheres into isolated perfused mice hearts, determining the spatial location of every microsphere in the hearts, and then visualizing regional flow patterns. We demonstrated application of these statistical and visualizing methods in a coronary artery ligation model in mice. Conclusions: These new methods provide tools to investigate the spatial and temporal changes in blood flow within organs of mice at a much higher spatial resolution than currently available by other methods.

Micro-CT is widely used in preclinical studies of small animals. Due to the low soft-tissue contrast in typical studies, segmentation of soft tissue organs from noncontrast enhanced micro-CT images is a challenging problem. Here, we propose an atlas-based approach for estimating the major organs in mouse micro-CT images. A statistical atlas of major trunk organs was constructed based on 45 training subjects. The statistical shape model technique was used to include inter-subject anatomical variations. The shape correlations between different organs were described using a conditional Gaussian model. For registration, first the high-contrast organs in micro-CT images were registered by fitting the statistical shape model, while the low-contrast organs were subsequently estimated from the high-contrast organs using the conditional Gaussian model. The registration accuracy was validated based on 23 noncontrast-enhanced and 45 contrast-enhanced micro-CT images. Three different accuracy metrics (Dice coefficient, organ volume recovery coefficient, and surface distance) were used for evaluation. The Dice coefficients vary from 0.45 ± 0.18 for the spleen to 0.90 ± 0.02 for the lungs, the volume recovery coefficients vary from 0.96 ± 0.10 for the liver to 1.30 ± 0.75 for the spleen, the surface distances vary from 0.18 ± 0.01 mm for the lungs to 0.72 ± 0.42 mm for the spleen. The registration accuracy of the statistical atlas was compared with two publicly available single-subject mouse atlases, i.e., the MOBY phantom and the DIGIMOUSE atlas, and the results proved that the statistical atlas is more accurate than the single atlases. To evaluate the influence of the training subject size, different numbers of training subjects were used for atlas construction and registration. The results showed an improvement of the registration accuracy when more training subjects were used for the atlas construction. The statistical atlas-based registration was also compared with the thin-plate spline based deformable registration, commonly used in mouse atlas registration. The results revealed that the statistical atlas has the advantage of improving the estimation of low-contrast organs.

Optimizing targeted radionuclide therapy requires patient-specific estimation of organ doses. The organ doses are estimated from quantitative nuclear medicine imaging studies, many of which involve planar whole body scans. We have previously developed the quantitative planar (QPlanar) processing method and demonstrated its ability to provide more accurate activity estimates than conventional geometric-mean-based planar (CPlanar) processing methods using physical phantom and simulation studies. The QPlanar method uses the maximum likelihood-expectation maximization algorithm, 3D organ volume of interests (VOIs), and rigorous models of physical image degrading factors to estimate organ activities. However, the QPlanar method requires alignment between the 3D organ VOIs and the 2D planar projections and assumes uniform activity distribution in each VOI. This makes application to patients challenging. As a result, in this paper we propose an extended QPlanar (EQPlanar) method that provides independent-organ rigid registration and includes multiple background regions. We have validated this method using both Monte Carlo simulation and patient data. In the simulation study, we evaluated the precision and accuracy of the method in comparison to the original QPlanar method. For the patient studies, we compared organ activity estimates at 24 h after injection with those from conventional geometric mean-based planar quantification using a 24 h post-injection quantitative SPECT reconstruction as the gold standard. We also compared the goodness of fit of the measured and estimated projections obtained from the EQPlanar method to those from the original method at four other time points where gold standard data were not available. In the simulation study, more accurate activity estimates were provided by the EQPlanar method for all the organs at all the time points compared with the QPlanar method. Based on the patient data, we concluded that the EQPlanar method provided a substantial increase in accuracy of organ activity estimates from 24 h planar images compared to the CPlanar using 24 h SPECT as the golden standard. For other time points, where no golden standard is available, better agreement between estimated and measured projections was observed by using the EQPlanar method compared to the QPlanar method. This phenomenon is consistent with the improvement in goodness of fit seen in both simulation data and 24 h patient data. Therefore, this indicates the improved reliability of organ activity estimates obtained though the EQPlanar method.

Knowledge on the effects of negative pressure wound therapy (NPWT) on the intra-thoracic organs is limited. The present study was performed to investigate the effects of NPWT on the volume of the intra-thoracic organs, using magnetic resonance imaging (MRI), in a porcine sternotomy wound model. Six pigs underwent median sternotomy followed by NPWT at -75, -125 and -175 mmHg. Six pigs were not sternotomised. MR images covering the thorax and heart were acquired. The volumes of the thoracic cavity, lungs, wound fluid and heart were then determined. The volumes of the thoracic cavity and intra-thoracic organs increased after sternotomy and decreased upon NPWT application. The total heart volume variation, which is inversely related to cardiac pumping efficiency, was higher after sternotomy and decreased during NPWT. NPWT did not result in the evacuation of wound fluid from the bottom of the wound. NPWT largely closes and restores the thoracic cavity. Cardiac pumping efficiency returns to pre-sternotomy levels during NPWT. This may contribute to the clinical benefits of NPWT over open-chest care, including the stabilizing effects and the reduced need for mechanical ventilation.

Some pathological conditions may affect osmolarity, which can impact cell, tissue, and organ volume. The hypothesis of this study is that changes in osmolarity affect the zero-stress state and mechanical properties of the aorta. To test this hypothesis, a segment of mouse abdominal aorta was cannulated in vivo and mechanically distended by perfusion of physiological salt (NaCl) solutions with graded osmolarities from 145 to 562 mosM. The mechanical (circumferential stress, strain, and elastic modulus) and morphological (wall thickness and wall area) parameters in the loaded state were determined. To determine the osmolarity-induced changes of zero-stress state, the opening angle was observed by immersion of the sectors of mouse, rat, and pig thoracic aorta in NaCl solution with different osmolarities. Wall volume and tissue water content of the rings were also recorded at different osmolarities. Our results show that acute aortic swelling due to low osmolarity leads to an increase in wall thickness and area, a change in the stress-strain relationship, and an increase in the elastic modulus (stiffness) in mouse aorta. The opening angle, wall volume, and water content decreased significantly with increase in osmolarity. These findings suggest that acute aortic swelling and shrinking result in immediate mechanical changes in the aorta. Osmotic pressure-induced changes in the zero-stress state may serve to regulate mechanical homeostasis.

A Korean adult male computational phantom was constructed based on the current anthropometric and organ volume data of Korean average adult male, and was applied to calculate internal photon dosimetry data. The stylised models of external body, skeleton, and a total of 13 internal organs (brain, gall bladder, heart, kidneys, liver, lungs, pancreas, spleen, stomach, testes, thymus, thyroid and urinary bladder) were redesigned based on the Oak Ridge National Laboratory (ORNL) adult phantom. The height of trunk of the Korean phantom was 8.6% less than that of the ORNL adult phantom, and the volumes of all organs decreased up to 65% (pancreas) except for brain, gall bladder wall and thymus. Specific absorbed fraction (SAF) was calculated using the Korean phantom and Monte Carlo code, and compared with those from the ORNL adult phantom. The SAF of organs in the Korean phantom was overall higher than that from the ORNL adult phantom. This was caused by the smaller organ volume and the shorter inter-organ distance in the Korean phantom. The self SAF was dominantly affected by the difference in organ volume, and the SAF for different source and target organs was more affected by the inter-organ distance than by the organ volume difference. The SAFs of the Korean stylised phantom differ from those of the ORNL phantom by 10-180%. The comparison study of internal dosimetry will be extended to tomographic phantom and electron source in the future.

Purpose of review Several technological advances have greatly improved three-dimensional sonography, which have improved acquisition and display capabilities. This review describes these technical changes as well as current applications of 3D sonography in prenatal diagnosis. Recent findings Recently published papers have emphasized the potential of getting a precise 'any plane of choice' from a three-dimensional volume, as a new way of scanning, based on the off-line analysis of a volume dataset. Surface mode has been used to demonstrate malformations and genetic diseases. The maximum rendering mode, which highlights bones, has great potential for imaging the nasal bones and the frontal bones with the metopic suture. Organ volume can be measured, but the utility of this in clinical practice remains to be determined. Three-dimensional ultrasound needs to be standardized. Summary Three-dimensional ultrasonography is the most rapidly developing technique in fetal imaging. New features will permit the transition from the era of 'sonography in two-dimensional planes' to 'volume ultrasound'.

Objectives: We sought to evaluate the capabilities of different magnetic resonance imaging (MRI)-based methodologies for measuring prostate volume. Materials and Methods: Twenty-four male beagles with benign prostatic hyperplasia were enrolled in a drug trial and imaged at 5 time points. A total of 120 prostate volumes were determined by MRI-based semiautomated segmentation. For planimetric assessment, 8 diameter locations were determined in the axial and coronal plane of the MRI slice with maximum extension of the prostate. Thirteen calculation models based on these diameters were determined by comparison to the reference volume and evaluated during treatment. Results: The segmented MRI prostate volume significantly correlated with post necropsy volume. The best diameter-based model also worked very well for monitoring prostate volume of dogs under treatment. Conclusions: MRI-based segmentation is highly accurate in assessing prostate volume. Diameter-based measurements are closely correlated to the segmented prostate volume and are feasible to monitor therapy.

▴ Miglustat is an orally administered ceramide glucosyltransferase inhibitor which prevents the lysosomal accumulation of glucocerebroside that occurs in patients with Gaucher’s disease. ▴ In noncomparative trials in patients with type 1 Gaucher’s disease, miglustat (50 or 100mg three times daily) for 6–12 months significantly reduced baseline liver and spleen volumes. At both 6 and 12 months, the reductions in organ volumes were greater with the higher dosage. ▴ Miglustat 50 or 100mg three times daily for 6–12 months had no significant effect on haemoglobin concentrations. Baseline platelet counts were not significantly improved by either dosage at 6 months, although the higher dosage significantly increased platelet counts at 12 months. ▴ In an open extension phase, patients continued to show further reductions in organ volume as well as significant improvements in haematological parameters at 24 and 36 months. ▴ In a 6-month randomised study in patients with type 1 Gaucher’s disease who had previously received long-term enzyme replacement therapy (ERT), liver volume reduction was greater with miglustat plus ERT than with ERT alone. ▴ Diarrhoea and weight loss were the most frequent adverse events associated with miglustat therapy. Fine tremor has been reported in approximately 30% of miglustat-treated patients.

To compare CT and MRI target volumes for nasopharyngeal carcinoma (NPC) and evaluate the role of intensity-modulated radiotherapy (IMRT) in treating composite CT+MRI targets.CT and T(1)/T(2)-weighted MRI scans were obtained for 8 consecutive NPC patients. Using CT, MRI, and fused CT/MRI, various target volumes (gross target volume, clinical target volume, and planning target volume [PTV]) and critical structures were outlined. For each patient, three treatment plans were developed: (1) a three-dimensional conformal RT (3D-CRT) plan using CT-based targets; (2) a 3D-CRT plan using composite CT+MRI targets; and (3) a IMRT plan using CT+MRI targets. The prescription dose was 57.6 Gy and 70.2 Gy to the initial and boost PTV, respectively. Treatment plans were compared using the PTV dose to 95% volume (D(95)), critical structure dose to 5% organ volume (D(5)), and mean dose.Compared with CT, the MRI-based targets were 74% larger, more irregularly shaped, and did not always include the CT targets. For CT-based targets, 3D-CRT plans, in general, achieved adequate target coverage and sparing of critical structures. However, when these plans were evaluated using CT+MRI targets, the average PTV D(95) was approximately 60 Gy (14% underdosing), and critical structure doses were significantly worse. The use of IMRT for CT+MRI targets resulted in marked improvement in the PTV coverage and critical structure sparing: average PTV D(95) improved to 69.3 Gy, brainstem D(5) to43 Gy (19% reduction), spinal cord D(5) to37 Gy (19% reduction), and the mean dose to the parotids and cochlea reduced to below tolerance (23.7 Gy and 35.6 Gy, respectively).CT/MRI fusion improved the determination of target volumes in NPC. In contrast to 3D-CRT, IMRT planning resulted in significantly improved coverage of composite CT+MRI targets and sparing of critical structures.

3D freehand ultrasound has extensive application for organ volume measurement and has been shown to have better reproducibility than estimates of volume made from 2D measurement followed by interpolation to 3D. One key advantage of free-hand ultrasound is that of image compounding, but this advantage is lost in many automated reconstruction systems. A novel method is presented for the automated segmentation and surface reconstruction of organs from sparse 3D ultrasound data. Preliminary results are demonstrated for simulated data, and two cases of in-vivo data; breast ultrasound and imaging of ovarian follicles.

Purpose: In this study, two commercially available programs were compared for the evaluation of delivered daily dose using cone beam CT (CBCT). Methods: Thirty (n=30) patients previously treated in our clinic (10 prostate, 10 SBRT lung and 10 abdomen) were used in this study. The patients' plans were optimized and calculated using the Pinnacle treatment planning system. The daily CBCT scans were imported into Velocity and RayStation along with the corresponding planning CTs, structure sets and 3D dose distributions for each patient. The organs at risk (OAR) were contoured on each CBCT by the prescribing physician and were included in the evaluation of the daily delivered dose. Each CBCT was registered to the planning CT, once with rigid registration and then again, separately, with deformable registration. After registering each CBCT, the dose distribution from the planning CT was overlaid and the dose volume histograms (DVH) for the OAR and the planning target volumes (PTV) were calculated. Results: For prostate patients, we observed daily volume changes for the OARs. The DVH analysis for those patients showed variation in the sparing of the OARs while PTV coverage remained virtually unchanged using both Velocity and RayStation systems. Similar results were observed for abdominalmore » patients. In contrast, for SBRT lung patients, the DVH for the OARs and target were comparable to those from the initial treatment plan. Differences in organ volume and organ doses were also observed when comparing the daily fractions using deformable and rigid registrations. Conclusion: By using daily CBCT dose reconstruction, we proved PTV coverage for prostate and abdominal targets is adequate. However, there is significant dosimetric change for the OARs. For lung SBRT patients, the delivered daily dose for both PTV and OAR is comparable to the planned dose with no significant differences.« less

Working with several mechanisms of critical local tissue damage, formulae are analytically derived that describe normal tissue complication probabilities (ntcps) for series-type radiotherapy complications arising in heterogeneous patient populations. Using the formulae, values are calculated for deltaD50(10)-the increase in dose leading to a 50% series-type complication rate (D50) when irradiated organ volume is reduced tenfold. From the structure of the ntcp formulae derived, it follows that dose-levels leading to clinically relevant serious complication rates (less than 5%) will change less with irradiated volume than will D50. Calculated values of deltaD50(10) for the heterogeneous series model are low-generally less than 6 Gy; such values are much lower than those calculated for the non-heterogeneous series model (27-37 Gy). These results suggest that if the dose-limiting toxicity of a radiotherapy treatment is a series-type complication with a local damage mechanism similar to any of those studied in this work, then even very substantial improvements in technique-leading to large reductions in highly dosed normal tissue volumes-would be unlikely to allow a useful degree of escalation of the dose delivered to the tumour, unless highly dosed normal tissue volumes can be reduced below the length-scale of a functional subunit.

Freehand 3D ultrasound is particularly appropriate for the measurement of organ volumes. For small organs, which can be fully examined with a single sweep of the ultrasound probe, the results are known to be much more accurate than those using conventional 2D ultrasound. However, large or complex shaped organs are difficult to quantify in this manner because multiple sweeps are required to cover the entire organ. Typically, there are significant registration errors between the various sweeps, which generate artifacts in an interpolated voxel array, making segmentation of the organ very difficult. This paper describes how sequential freehand 3D ultrasound, which does not employ an interpolated voxel array, can be used to measure the volume of large organs. Partial organ cross-sections can be segmented in the original B-scans, and then combined, without the need for image-based registration, to give the organ volume. The inherent accuracy (not including position sensor and segmentation errors) is demonstrated in simulation to be within +/- 2%. The in vivo precision of the complete system is demonstrated (by repeated observations of a human liver) to be +/- 5%.

RATIONALE AND OBJECTIVES A radiologist often wishes to measure organ volume or monitor changes in internal lesion volume during treatment. If this can be determined via three-dimensional ultrasound, the relative simplicity of the procedure and the decreased cost and known risks to the patient would make this method an attractive alternative to other modalities. METHODS Three-dimensional ultrasound scans were made of six phantoms: four nonechogenic spheres, one echogenic sphere, and one echogenic, irregularly shaped phantom. A total of 22 volume scans were produced. Volume estimations were made using data from cross-sectional areas and from linear measurements. In all, 193 volume estimations were made. These results were compared with known volumes and with volume estimates from computed tomography scans. RESULTS Three-dimensional ultrasound detected size differences of 10% with 95% certainty. CONCLUSIONS The accuracy and precision of volume estimates via three-dimensional ultrasound is at least as good as those obtained via conventional ultrasound.

Results: Median biological effective dose (BED) at an a/b ratio of 10 as the prescribed dose was 84.5GyE10 (range, 60-96.8GyE10). Eleven (40%) patients developed acute Grade 1, 12 (45%) patients Grade 2, and 4(15%) patients Grade 3 acute dermatitis. In uni-variate analysis, factors associated with onset of Grade 2 or higher acute dermatitis included BED (GyE10) as prescription dose (p Z 0.030), skin dose parameter (V45-70GyE10) (p Z 0.044, 0.039, 0.031, 0.015, 0.010, and 0.022, respectively), and gradient dose index (GDI65GyE and 70GyE) (p Z 0.031, and 0.048, respectively). When plotting the p value of the logistic regression analysis between the variables, V65 GyE10 of skin surface area show the strongest statistical significance (p & 0.01). Conclusions: High incidence of severe (Grade 2 or higher) radiation dermatitis (60% of entire cohort) was observed during clinical use of PBT in HNC patients. The entrance portal area to skin irradiated volume with 45-70GyE10 was possible predictor for acute skin toxicity and higher dose volume of superficial regions over 65GyE10 should be considered in the treatment planning as sensitive organ volume in PBT. Author Disclosure: H. Inokuchi: None. T. Nakamura: None. T. Tomoda: None. A. Takada: None. K. Takayama: None. C. Makita: None. M. Shiomi: None. T. Kato: None. N. Fuwa: None.

Purpose: To determine the impact of the deformation of rectum and bladder on the assessment of dose‐volume constraints for these organs at risk (OARs) in adaptive prostate IMRT. Methods: Five prostate cancer patients treated with both prostate and seminal vesicle as the initial PTV and with prostate only as the boost PTV were selected for this study. All patients received two CT simulations with the first CT scanned for the initial treatment volume followed by a second CT simulation after 45 Gy. All patients were treated to a total dose of 79.2 Gy in 1.8 Gy fractions delivered with seven‐coplanner IMRT beams. MIM‐Adaptive deformation workflow (MIMVista, Cleveland, OH) was used to perform deformation image registration of the two CTimage sets. For evaluation of the accumulative dose delivered to the OARs in presence of organ deformation, MIM‐Dose deformation tool was used to register the deformed dose matrices of two CT sets. The dose‐volume constraints, D25%, calculated for rectum and bladder with and without consideration of organ deformation were compared. Results: Differences in rectal D25% of up to 9.8% (from −9.8% to +2.8%) and in bladder D25% of up to 19.5% (from −19.5% to +9.0%) were observed. The deformation of OARs during IMRT caused the values of D25% for rectum to change from −646 cGy to +173 cGy and for bladder from −831 to +541 cGy from patient to patient. Conclusions: Discrepancies in OAR dose‐volume constraints can be calculated using modern deformable registration tools with and without consideration of organ volume change and deformation and should be carefully considered in the evaluation of OAR complication risks in adaptive prostate IMRT. MIMVista work station which was used to conduct this research was provided by MIM software Inc.

Designing dose distributions that minimize the risk of radiation‐induced normal tissue toxicity is one of the hardest parts of treatment planning. Commonly, many planners use the tolerance guidelines set forth in the famous 1991 ‘Emami paper’. A wealth of more recent information exists but is dispersed over many, diverse publications. Therefore, AAPM and ASTRO funded the QUANTEC (Quantitative Analysis of Normal Tissue Effects in the Clinic) effort, wherein over 60 volunteer physicists and radiation oncologists collaborated in an expert review of the literature from the “3DCRT” era. Consensus dosimetric guidelines for 16 normal organs were published in early 2010 (International Journal of Radiation Oncology, Biology and Physics V76, #3S supplement). For some complications, the QUANTEC recommendations are in general concordance with the Emami guidelines but for others there are notable differences and the mathematical models of normal tissue complication risk built accordingly reveal wide variations among the different studies. The reasons for these differences and what needs to be done to reconcile them with previous and future clinical practice will be discussed for selected disease sites and organs. Course outline: 1. A user's guide to QUANTEC: All the organ‐complication articles have the same format and address the same topics: clinical significance, complication endpoints, organ volume definition, literature review, non‐dosimetric risk factors, mathematical/biological models, special situations, recommended dose‐volume limits, future studies. The difficulties QUANTEC encountered relative to each section are instructive, as they indicate problems in the way outcomes are reported in the literature. These will be described to aid in understanding the limitations of the Quantec reviews and to improve the state of knowledge going forward. [Presenter: Andrew Jackson, MSKCC] 2. What's new since Emami: For some major dose‐limiting complications, the QUANTEC and ‘Emami’ guidelines differ substantially — for others there is general concordance. Examples of each sort will be presented along with suggestions as to clinical application. [Presenter: Larry Marks, MD, UNC] Learning Objectives: 1. Understand the broad goals and methods of the QUANTEC review. 2. Identify several organs where the dose/volume' outcome data presented by QUANTEC is ‘significantly’ different from what was presented by Emami in 1991. 3. Broadly understand the shortcomings of the QUANTEC review and methods and opportunities for acquiring additional and improved information.

Purpose: In an effort to accurately consider historical radiation in treatment planning and outcome analysis for pediatric radiotherapy patients, we investigate the correlations of the volume of the liver and kidneys with age, total body mass, and body height of pediatric patients. Method and Materials: The liver and kidneys were delineated upon CTimages acquired for 48 patients (27 male, 21 female) ranging in age from 0.7 to 19.3 years at the first CT acquisition. For age‐based correlations, statistics were compiled among all images and among only the images acquired pre‐treatment. For the mass‐based and height‐based correlations, total patient body mass and height were obtained from supplemental chart information. Plots of total‐kidney volume versus age were compiled among male and female patients separately. Plots of liver and total‐kidney volume versus body weight and body height were complied from among all patients. Linear fits were applied to each data set, and the standard deviation of the difference between the measurement and the linear fit was compiled. Results: Increased liver and kidney volume with increasing age, body mass, and height are apparent. Excluding post‐treatment image data led to improved linear correlations. Linear fits suggest larger kidney volume at birth for males (99 cm3 vs. 63 cm3 for females), although for both males and females the kidney growth rate is similar (approximately 17 cm3 per year). The ratio of the right‐ to left‐kidney volume was 0.95±0.14. Although there is relatively little variation in body mass among the patient set, greater body mass appears to predict greater organ volume. Conclusions: The correlation of liver and kidney volume with patient age, body mass, and height are apparent for pediatric patients, and can be used to construct organ‐growth models that may be useful in image registration, dose accumulation and radiation‐response assessment for pediatric radiotherapytreatment planning.