Pelvic Volume Research Articles

Fully automated pelvic bone segmentation in multiparameteric MRI using a 3D convolutional neural network

BackgroundAccurate segmentation of pelvic bones is an initial step to achieve accurate detection and localisation of pelvic bone metastases. This study presents a deep learning-based approach for automated segmentation of normal pelvic bony structures in multiparametric magnetic resonance imaging (mpMRI) using a 3D convolutional neural network (CNN).MethodsThis retrospective study included 264 pelvic mpMRI data obtained between 2018 and 2019. The manual annotations of pelvic bony structures (which included lumbar vertebra, sacrococcyx, ilium, acetabulum, femoral head, femoral neck, ischium, and pubis) on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) images were used to create reference standards. A 3D U-Net CNN was employed for automatic pelvic bone segmentation. Additionally, 60 mpMRI data from 2020 were included and used to evaluate the model externally.ResultsThe CNN achieved a high Dice similarity coefficient (DSC) average in both testing (0.80 [DWI images] and 0.85 [ADC images]) and external (0.79 [DWI images] and 0.84 [ADC images]) validation sets. Pelvic bone volumes measured with manual and CNN-predicted segmentations were highly correlated (R2 value of 0.84–0.97) and in close agreement (mean bias of 2.6–4.5 cm3). A SCORE system was designed to qualitatively evaluate the model for which both testing and external validation sets achieved high scores in terms of both qualitative evaluation and concordance between two readers (ICC = 0.904; 95% confidence interval: 0.871–0.929).ConclusionsA deep learning-based method can achieve automated pelvic bone segmentation on DWI and ADC images with suitable quantitative and qualitative performance.

Development of an Endovascular Model of Pelvic Hemorrhage Using Volumetric Computed Tomography Validation

Purpose Uncontrolled pelvic hemorrhage from trauma is associated with mortality rates above 30%. The ability of an intervention to reduce blood loss from pelvic trauma is paramount to its success. The objective of this study was to determine if computed tomography volumetric analysis could be used to quantify blood loss in a porcine endovascular pelvic hemorrhage model. Materials and Methods Yorkshire swine under general anesthesia underwent balloon dilation and rupture of the profunda femoris artery, which was confirmed by digital subtraction angiography. Computed tomography angiography and postprocessing segmentation were performed to quantify pelvic hemorrhage volume at 5 and 30 minutes after injury. Continuous hemodynamic and iliofemoral flow data were obtained. Baseline and postinjury hemoglobin, hematocrit and lactate were collected. Results Of 6 animals enrolled, 5 survived the 30-minute post-injury period. One animal died at 15 minutes. Median volume of pelvic hemorrhage was 141±106 cm3 at 5 minutes and 302±79 cm3 at 30 minutes with a 114% median increase in hematoma volume over 25 minutes (p=0.040). There was a significant decrease in mean arterial pressure (107 to 71 mm Hg, p=0.030) and iliofemoral flow (561 to 122 mL/min, p=0.014) at 30 minutes postinjury, but no significant changes in hemoglobin, hematocrit, or heart rate. Conclusion Computed tomography volumetric analysis can be used to quantify rate and volume of blood loss in a porcine endovascular pelvic hemorrhage model. Future studies can incorporate this approach when evaluating the effect of hemorrhage control interventions associated with pelvic fractures.

Diagnostic accuracy of CT imaging parameters in pelvic lipomatosis.

To predict the diagnosis of pelvic lipomatosis (PL) by assessing CT imaging parameters. Fifty clinically proven PL patients and 50 controls were included. Two radiologists recorded the types of bladder shapes and measured the following CT imaging parameters: (1) pelvic fat volume (PFV); (2) a set of morphological indices of bladder and rectosigmoid, including the ratio of craniocaudal to anterior-posterior length of bladder (CC/AP), angle between anterior and posterior wall (AAP), relative length of posterior urethra (rLPU), right and left angles between bladder and seminal vesicle (RABS and LABS), distance from verumontanum to anterior wall of rectum (DVR) and rectosigmoid morphological index (RMI). Secondary complications were also noted. The results were evaluated by an unpaired t test, ROC analysis and logistic regression. All CT imaging parameters except RMI (p = 1.000) indicated a statistical difference between PL and controls (p < 0.01). The AUCs of these parameters were between 0.724 (for rLPU) and 0.993 (for AAP). The sensitivity and specificity were 94% and 98% for AAP and 92% and 94% for the combined model, respectively. 23 patients were pathologically diagnosed with cystitis glandular. The incidence of hydronephrosis in the PL group was higher than that in the control group (p < 0.01). CT imaging parameters can predict the diagnosis of PL. The combined model of objective parameters including PFV, rLPU and DVR showed the best diagnostic performance for PL.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ КОРОВ РАЗНЫХ ЭКСТЕРЬЕРНО-КОНСТИТУЦИОНАЛЬНЫХ ТИПОВ

Improvement of the genetic potential in terms of cows’ productivity and creation of high milk-yield cattle with good health and long productive lifetime characteristics is impossible without systematic evaluation of such traits as milk-yield, exterior, and constitution type. The aim of our research was to study the trends in exterior traits genetic selection parameters changing, determine the extent of interconnection between cow productivity traits and constitution type among the Black-Motley and Kholmogory cow breeds of the Udmurt Republic. The research based on cow breeding-stocks was carried out in 2018–2020. The sampled population included 449 specimens. The whole cow population to be analyzed was divided in 3 groups by the productivity level: 1 – low (up to 6,000 kg); 2 – moderate (from 6,000 to 8,000 kg); 3 – high (over 8,000 kg). High milk-yield cows were higher – withers height was higher by 1.5% and 1.4% (P &lt; 0.05) – and had more elongated body (by 1.0% and 0.8%) as compared with the 1st and 2nd group specimens. Low milk-yield cows (up to 6,000 kg) had short stature and big-boned constitution type with better-developed skeleton. They had greater values of such parameters as the chest width (by 1.6%), wide hip width (by 7.3%, P &lt; 0.01), width of loin (by 13.2%, P &lt; 0.01), and metacarpus girth (by 3.2%, P &lt; 0.05). Cows with a productivity level over 8,000 kg of milk per 305 days of lactation had relatively high value of the Pelvic arch length (by 2.0% and 2.3%, Р &lt; 0.05) and the depth of loin (by 1.3% and 1.5%) with insignificant difference in rump bone length. The lowest value of the mean exterior index of constitution type (by 3.0%, P &lt; 0.05) was observed in high milkyield cows that is the evidence of the constitution proportionality, namely, optimal relation between the body volume and the height of a cow. Moreover, the Pelvic arch index – the ratio of the Pelvic arch volume to the body length – also testifies to harmonious constitution. High milk-yield cows demonstrated this index to be the lowest (by 3.8%, Р &lt; 0.01) and featured more harmonious constitution.

Segmental Volume and Circulatory Changes that Occur in Humans and Rhesus Monkeys During 4 Hour, -6 Degree Head Down Tilt.

Nonhuman primates are often used to investigate physiologic processes that occur in man during aerospace/cardiovascular orthostatic research. Few studies have compared nonhuman primates and man under identical test conditions to assess the degree of similarity between the two species. Impedance plethysmography was used to measure calf, thigh, pelvic, thoracic, upper arm, and lower arm volume changes in eight rhesus (Macacca Mulatta) monkeys and twelve human subjects during four hour exposures to −6 degree head down tilt (HDT).

Hemodynamically unstable pelvic fracture: A damage control surgical algorithm that fits your reality.

Pelvic fractures occur in up to 25% of all severely injured trauma patients and its mortality is markedly high despite advances in resuscitation and modernization of surgical techniques due to its inherent blood loss and associated extra-pelvic injuries. Pelvic ring volume increases significantly from fractures and/or ligament disruptions which precludes its inherent ability to self-tamponade resulting in accumulation of hemorrhage in the retroperitoneal space which inevitably leads to hemodynamic instability and the lethal diamond. Pelvic hemorrhage is mainly venous (80%) from the pre-sacral/pre-peritoneal plexus and the remaining 20% is of arterial origin (branches of the internal iliac artery). This reality can be altered via a sequential management approach that is tailored to the specific reality of the treating facility which involves a collaborative effort between orthopedic, trauma and intensive care surgeons. We propose two different management algorithms that specifically address the availability of qualified staff and existing infrastructure: one for the fully equipped trauma center and another for the very common limited resource center.

Pelvic floor parameters in women with gynecological endocrinopathies: a systematic review.

There is no pooled information about pelvic floor parameters (muscle assessment, disorders) of women with gynecologicaL endocrinopathies (eg. polycystic ovary syndrome, congenital adrenal hyperplasia, premature ovarian insufficiency). Given that, a systematic review was performed on the Pubmed, Scopus, Google Scholar, Scielo and PEDro databases regarding the main gynecological endocrinopathies [polycystic ovary syndrome (PCOS), premature ovarian insufficiency (POI), congenital adrenal hyperplasia (CAH) and hyperprolactinemia (HPL)] since their inception to April 2020. Data quality assessment was made by the Newcastle-Ottawa Scale (NOS) adapted for cross-sectional studies. A total of 4,272 results were retrieved from all databases. After excluding duplicate results and screening by title and abstract, nine studies were selected for quantitative analysis. Seven studies were performed with women with PCOS and two studies with POI. Women with PCOS presented a higher prevalence of urinary incontinence (UI) among obese women, a higher thickness of the levator ani muscle, and higher levels of muscle activity measured by surface electromyograph when compared to the control women. Regarding POI, there was no association with UI, FI, and POP. NOS found that the quality assessment for these selected studies ranged from 5 to 8. We concluded that higher pelvic muscle activity and volume were found in women with PCOS, with further studies needed to confirm this data. Literature was scant about POI, CAH, and HPL.

A Dosimetric Comparison of Pelvic Lymph Node Volume Delineation Using Magnetic Resonance Imaging Versus Computed Tomography in Gynecological Cancers

Definitive external beam radiotherapy (EBRT) targets the primary tumor and at-risk pelvic lymph node groups. Magnetic resonance imaging (MRI), with its superior soft tissue definition compared with computed tomography (CT), is routinely used in cervical cancer EBRT planning to accurately define the primary tumor. MRI can also provide more accurate visualization of lymph nodes, vessels and tissue planes, such that MRI-based nodal clinical target volume (CTVn) delineation may result in smaller volumes and reduced dose to organs at risk (OAR). The aim of this study was to dosimetrically compare EBRT plans in patients with CTVn delineation using MRI fused with CT (CT-MRI) and CT alone. This study was important to examine the advantage of MRI in radiotherapy; prior to the addition of a new MRI simulator and MRI Linac in our center. Nine patients with cervical cancer and two patients with recurrent endometrial cancer were treated using definitive EBRT at our institution with diagnostic MRI scans and were included in this study. The planning CT (pCT) scan for each patient was obtained and fused with T2-weighted MRI scan using bony landmarks and deformable registration. Two separate CTVn volumes were contoured by a radiation oncologist, one based on pCT and a second based on MRI. All other structures including primary CTV (CTVp) and OAR (rectum, sigmoid, bowel, bladder, and femurs) were contoured on the pCT only. Planning target volume (PTV) contours were created by combining CTVn and CTVp with a 1 cm margin. Volumetric modulated arc therapy (VMAT) plans were generated for both pCT-based PTVs and CT-MRI-based PTVs using institutional protocol. Plans were evaluated for PTV volume, coverage (D98) and dose to OAR. Differences between pCT and CT-MRI were analyzed using paired t-tests and results are presented as means and SD (standard deviation). Twenty-two VMAT plans were generated. The mean (SD) PTV volume was 1485.9 cm³ (171.7) for pCT and 1424.5 cm³ (168.0) for the CT-MRI plan (p<0.001). The mean (SD) PTV D98 for pCT and CT-MRI was the same at 43.1 Gy (0.3) (p = 0.677). There was no significant dosimetric difference noted to any of the OAR (Table). This novel method for reducing the CTVn volume by using MRI to avoid anatomical boundaries such as fascial planes and bowel produced an overall reduction in the target volume. However, this did not result in a dosimetric advantage to the surrounding OAR. The most clinically relevant benefit of MRI in gynecological EBRT planning remains in the accurate definition of the primary tumor.Tabled 1Abstract 3080; Table;Organ at RiskpCT, Mean (SD)CT-MRI, Mean (SD)p-valueRectum (V40)56.9% (5.2)49.8% (11.8)0.111Sigmoid (V40)82.2% (20.6)78.7% (28.7)0.588Sigmoid (V45)27.5% (13.9)26.5% (17.8)0.787Bowel (V40)197.8cm³ (97.8)210.8cm³ (103.5)0.605Bowel (V45)73.3cm³ (43.1)67.3cm³ (45.9)0.664Bladder (V45)22.5% (4.1)24.5% (5.9)0.172Right Femur (V30)10.9% (2.3)10.3% (2.9)0.458Left Femur (V30)12.0% (3.1)11.6% (2.2)0.570 Open table in a new tab

Effect Of Large Field RT Vs Small Field Prostate RT On Lymphocyte Count For Localized Prostate Cancer (PC)

It has been postulated that circulating lymphocytes exposed to long-course RT may have immunosuppressive effects with prognostic implications. This retrospective study is designed to evaluate the effects of pelvic RT for the treatment of PC on lymphocytes. The hypothesis is large field pelvic RT for PC results in increased exposure of circulating lymphocytes compared to small field prostate only RT, resulting in greater reduction of post treatment lymphocyte count independent of irradiated marrow volume and total RT dose. The specific aim is to compare differences in RT induced reduction in lymphocytes in patients receiving large field (pelvic) vs small field (prostate only) RT for localized PC. This review includes 84 patients with localized PC who received RT as primary treatment and have undergone pretreatment (within 8 wks) and post-treatment (within 2 wks) CBC with differential. Irradiated treatment volumes, irradiated marrow volumes, and total RT dose are correlated with relative reduction in post-treatment ANC, ALC and NLR to pretreatment values. Univariate and multivariate analyses are performed. There were 43 patients in the small field group, and 41 in the large field group. V10, V20, V25, V30, V45, prescribed dose (TD), and VTD for total body volume and pelvic marrow volume were recorded. Pretreatment ANC, ALC and NLR ratio were not statistically different between the groups. The mean post-treatment ANC, ALC and NLR were compared with two-sample t-test. Post-treatment ANC did not differ between the groups. The post-treatment ALC was significantly different in the large field group (p = 0.041), as were the NLR (p = 0.0015) and the % decline in ALC (p = 0.002). These statistically significant differences reflected a 33% decrease in ALC for the small field group and a 50% decrease for the large field group. Univariate regression analysis assessed correlation between these statistically significant ALC related measures and TD, VTD, marrow V10-V45, and body V10-V45. The ALC was most strongly correlated with marrow V30 (p = 0.04), and to a lesser extent with marrow V25 and V45, and body V20 and V30. TD, VTD, and V10 were not predictive. Univariate analysis of the NLR ratio and % decrease in ALC showed that each of these measures was correlated with all marrow V10-V45 volumes, and all body V10-V45 volumes, with the strongest correlation being body V30 volume for each. On multivariate analysis, none of the dose volume measures significantly predicted for the post-treatment ALC or % decline in ALC, although there was a trend for marrow V10 and marrow V30. The NLR ratio was strongly correlated with body V20 (p = 0.031). Pelvic RT impacted ALC and the NLR ratio, with field size and moderate dose volumes having a pronounced impact, with statistically significant measures most strongly correlated with total body dose-volumes rather than marrow dose-volumes.

Impact of Pelvic Intensity-modulated Radiotherapy (IMRT) on Lymph Node Coverage and Dose to Critical Organs, Compare to Three-Dimensional Conformal Radiation Therapy (3D-CRT), in Localized High-Risk Prostate Cancer

Men with high risk prostate cancer (HR-PrCa) are typically treated with combined androgen deprivation therapy and curative radiotherapy (RT) consisting of pelvic nodal and prostate/seminal vesicle (PrSV) irradiation followed by PrSV boost RT. 3D-CRT or IMRT are used for the treatment of pelvic nodes. A phase II randomized study examining the effect of RT technique on patient Quality of Life (QoL) was completed in our institution. Here, we report an early analysis of the dosimetric impact of 3D-CRT versus IMRT in patients participating in this study. A total of 105 men with HR-PrCa were randomized at 1:1 ratio to receive either pelvic 3D-CRT (standard 4-field conformal technique) or multi-beam IMRT, consisting of 4500cGy in 25 fractions to planning target volume (PTV) 1, followed by boost RT to PTV2 of 2496cGy in 13 fractions. The latter was delivered using a 7-field IMRT in all patients. Organs at risk (OAR) and clinical target volumes (CTV) were delineated on CT simulation images. The lymph node target included the common, internal, external iliac, obturator and pre-sacral lymph nodes in accordance with RTOG guidelines. CTV1 consisted of nodal CTV plus PrSV. CTV2 was minimized to PrSV. The PTV consisted of an expansion of 7 mm beyond CTV. For consistency, in comparison between the two techniques, IMRT fields were modified to results to similar superior border coverage as 3D-CRT, at the level of L5-S1. Bladder and rectum were contoured as solid organs. To take inter-fractional bowel motion into account, bowel was delineated as whole pelvic and abdominal cavity excluding bones, muscle, and other OAR. Pelvic RT with 3DCRT missed significant percentage of pelvic nodal volume. PTV1 D95% showed mean difference of -4.96, 95% CI (-6.41, -1.74); p = 0.0013 and D99% showed mean difference of -11.56, 95% CI (-14.96, -8.17); p< 0.00001 in favor of IMRT. There was significant difference in PTV1 heterogeneity index (D2%-D95%/D50%) (Mean diff = 0.22, 95%CI (0.14, 0.29); P<0.00001). IMRT decreased dose to OAR. Rectum V30 was 97% in 3DCRT compare to 93.41% in IMRT arm with absolute difference of 3.81% (95% CI (1.52, 6.11); P = 0.0014). Bladder V40 and V50 were significantly reduced (V40: 84 % vs 62% for 3DCRT vs IMRT, absolute difference of 22% (95%, CI (15.55, 28.2); P<0.0001); V50 absolute reduction of 18% with IMRT (95%, CI (11.53, 24.48); P<0.0001). Similarly, IMRT reduced total body/bone irradiation significantly. This randomized study of 3D-CRT versus pelvic IMRT is an appropriate setting to investigate the dosimetric impact of pelvic IMRT and help define its potential benefits on patient QoL. This early analysis suggests that utilization of IMRT for pelvic RT could offer dosimetric advantages by improve lymph node coverage and reducing RT dose to OAR. The results are in agreement with an improved bowel-related QoL observed in this study. On-going analysis examines correlations between dosimetric and patient QoL data.

Image Guidance with Alignment To Bladder-Rectal Interface Versus Pelvic Bone In Post-Prostatectomy Radiotherapy: Implications For Concurrent Nodal Irradiation

The bladder-rectal interface (BRI) position is often dependent on bladder and rectal filling in post-prostatectomy patients. Nodal irradiation is of increasing importance given recent randomized data. It is unknown how alignment to the BRI may impact nodal coverage. We hypothesized that the shifts between alignment to the BRI vs pelvic bone would fall within the standard nodal PTV expansion. CBCTs from patients receiving prostate bed RT using 6 degrees of freedom (6DOF) couch were analyzed. At time of treatment, each CBCT was approved by a prostate specialized radiation oncologist prioritizing alignment to the BRI and prostate bed. Retrospectively each CBCT was re-aligned to pelvic bone. Reference bone points were chosen to represent the superior extent of pelvic nodal target volumes {midline sacral promontory (SP) and anterior aspect of sacroiliac joints at the S1-S2 (LSI and RSI)}. Three cardinal coordinates of each reference point (x, y, and z), were transformed to the machine coordinate system. Transformation matrices were defined by the parameters: lat (x), vert (y), long (z), pitch, roll, and rotation obtained with prospective matching. Using transformation matrices, alignment to the BRI was compared to bone alignment for each reference point by differences between the two sets of coordinates (x”-x’), (y”-y’), (z”-z’). A total of 139 CBCT from 14 patients were evaluated. Differences between coordinates with both alignment techniques were calculated and evaluated across all image sets (see table below). Mean differences between spatial alignment to BRI vs bone were <1.5 mm and >95% of all offsets were ≤5 mm. Approximately 75% of all coordinate differences were ≤1 mm and 90% were ≤3 mm. Less than 4% were >5 mm. Only 2 patients (4 CBCTs) exhibited >7 mm offsets between BRI and bone points. Coordinate differences >3 mm and >5 mm were more common in y (12.5% and 6%) and z (14.6% and 2.9%) than in x dimension (1.4% and 1.4%), respectively. Differences in pitch, roll, and rotation >1° were noted in n = 8, 3, and 1 CBCT sets, respectively. These data suggest that alignment to the prostate bed and BRI did not result in large offsets at the superior aspect of the pelvis. With rare exception, the required shifts should fall within the standard nodal PTV expansion. The impact of bladder and rectal filling on nodal target alignment and coverage is the subject of ongoing investigation.Abstract 4102; TableMean (mm)Std Dev (mm)≤ 1 mm (n)>1-3 mm (n)>3-5 mm (n)>5-7 mm (n)>7 mm (n)Point 1 SPx0.33 (0-8.72)0.951307011y1.40 (0-11.18)1.938140963z0.97 (0-5.92)1.50102191440Point 2 LSIx0.37 (0-8.81)0.981307011y1.39 (0-11.17)1.938042953z0.97 (0-5.93)1.48102161830Point 3 RSIx0.36 (0-8.64)0.941307011y1.40 (0-11.17)1.938141953z1.03 (0-6.20)1.55100171750 Open table in a new tab

Pelvic floor morphometrical and functional changes immediately after pelvic floor muscle training and at 1-year follow-up, in older incontinent women.

To compare the effects of group-based and individual physiotherapy for stress or mixed urinary incontinence (UI) on pelvic floor morphometry, pelvic floor muscle (PFM) function, and related self-efficacy, immediately after treatment and at 1 year. This is a planned secondary analysis of the group rehabilitation or individual physiotherapy study, an assessor-blinded, randomized, noninferiority trial. Eligible participants included 362 community-dwelling older women with symptoms of stress/mixed UI. After learning how to contract PFMs, participants completed 12 weeks of PFM training, either individually (one-on-one) or as part of a group (eight women). Pelvic floor transperineal ultrasound volumes (morphometry), PFM intravaginal dynamometric data (function), and self-efficacy in performing PFM exercises were acquired at baseline, posttreatment, and at 1 year. Groups were comparable at all time points. Immediately posttreatment, both groups demonstrated significant changes in pelvic floor morphometry during coughs, and in PFM function during contractions and coughs. Participants also reported improved self-efficacy in performing PFM exercises. Results were sustained at 1year. When participants coughed, pelvic floor structures were better supported (reflected by less caudal movement of the puborectalis sling and a smaller opening of the levator hiatus) in a pattern consistent with the "knack"strategy. Furthermore, both interventions resulted in stronger, faster, more coordinated, and more endurant PFMs. In older women with stress or mixed UI, both individual and group-based PFM training resulted in comparable improvements in overall PFM function, pelvic floor morphometry during coughs, and related self-efficacy in performing PFM exercises, which were sustained at 1 year.

Editorial Comment on: Volumetric and acetabular changes in the bony pelvis associated with primary closure of classic bladder exstrophy

This manuscript examines a small subset of bladder exstrophy patients and describes pelvic bony anatomy. 18 patients underwent an MRI after closure, between 2 and 188 days after surgery, and 1/3 of these patients had osteotomies. All patients who were included had a successful closure, but there are no selection criteria provided. Fourteen patients had a pre and post closure MRI, and found that pelvic volumes increased, however, the authors admitted that this is likely due to normal patient somatic growth. Both pre and post closure pelvic volumes were different from controls. However, the authors demonstrate that acetabular angles more closely resembled controls after closure than pre-operatively. Volumetric and acetabular changes in the bony pelvis associated with primary closure of classic bladder exstrophyJournal of Pediatric UrologyVol. 16Issue 6PreviewRepair of classic bladder exstrophy (CBE) is known to alter dimensions of the bony pelvic ring. Pelvic volume and acetabular configuration are additional metrics which merit analysis in the reconstruction process. Advances in magnetic resonance imaging (MRI) allow for precise elucidation of such anatomy in pediatric patients, providing enhanced knowledge of how primary reconstruction may impact factors in pelvic health. Full-Text PDF

Auto-segmentations by convolutional neural network in cervical and anorectal cancer with clinical structure sets as the ground truth

BackgroundIt is time-consuming for oncologists to delineate volumes for radiotherapy treatment in computer tomography (CT) images. Automatic delineation based on image processing exists, but with varied accuracy and moderate time savings. Using convolutional neural network (CNN), delineations of volumes are faster and more accurate. We have used CTs with the annotated structure sets to train and evaluate a CNN. Material and methodsThe CNN is a standard segmentation network modified to minimize memory usage. We used CTs and structure sets from 75 cervical cancers and 191 anorectal cancers receiving radiation therapy at Skåne University Hospital 2014-2018. Five structures were investigated: left/right femoral heads, bladder, bowel bag, and clinical target volume of lymph nodes (CTVNs). Dice score and mean surface distance (MSD) (mm) evaluated accuracy, and one oncologist qualitatively evaluated auto-segmentations. ResultsMedian Dice/MSD scores for anorectal cancer: 0.91–0.92/1.93–1.86 femoral heads, 0.94/2.07 bladder, and 0.83/6.80 bowel bag. Median Dice scores for cervical cancer were 0.93–0.94/1.42–1.49 femoral heads, 0.84/3.51 bladder, 0.88/5.80 bowel bag, and 0.82/3.89 CTVNs. With qualitative evaluation, performance on femoral heads and bladder auto-segmentations was mostly excellent, but CTVN auto-segmentations were not acceptable to a larger extent. DiscussionIt is possible to train a CNN with high overlap using structure sets as ground truth. Manually delineated pelvic volumes from structure sets do not always strictly follow volume boundaries and are sometimes inaccurately defined, which leads to similar inaccuracies in the CNN output. More data that is consistently annotated is needed to achieve higher CNN accuracy and to enable future clinical implementation.

Volumetric Markers of Body Composition May Improve Personalized Prediction of Major Arterial Bleeding After Pelvic Fracture: A Secondary Analysis of the Baltimore CT Prediction Model Cohort.

This work is a retrospective secondary analysis of a single institution cohort used in the development of the Baltimore CT prediction model. The cohort includes 115 consecutive patients that underwent admission contrast-enhanced CT of the abdomen and pelvis for blunt trauma with pelvic ring disruption followed by conventional angiography. Major arterial injury requiring angioembolization served as the outcome variable. Angioembolization was required in 73/115 patients (63% of the cohort). Average age was 46.9 years (±SD 20.4). Body composition measurements were determined as 2-dimensional (2D) or 3-dimensional (3D) parameters and included mid-L3 trabecular bone attenuation, abdominal visceral fat area or volume, and percent muscle fat fraction (as a marker of sarcopenia) measured using segmentation and histogram analysis. Models incorporating 2D (Model B) or 3D markers (model C) of body composition showed improvement over the original Baltimore model (model A) in all parameters of performance, quality, and fit (area under the receiver-operating curve [AUC], Akaike information criterion, Brier score, Hosmer-Lemeshow test, and adjusted-R2). Area under the receiver-operating curve increased from 0.83 (A), to 0.86 (B), and 0.88 (C). The greatest improvement was seen with 3D parameters. Once automated, quantitative visualization tools providing "free" 3D body composition information can be expected to improve personalized precision diagnostics, outcome prediction, and decision support in patients with bleeding pelvic fractures.

Volumetric and acetabular changes in the bony pelvis associated with primary closure of classic bladder exstrophy

Repair of classic bladder exstrophy (CBE) is known to alter dimensions of the bony pelvic ring. Pelvic volume and acetabular configuration are additional metrics which merit analysis in the reconstruction process. Advances in magnetic resonance imaging (MRI) allow for precise elucidation of such anatomy in pediatric patients, providing enhanced knowledge of how primary reconstruction may impact factors in pelvic health. An IRB-approved exstrophy-epispadias database of 1337 patients was reviewed for patients with CBE who had pelvic MRI performed before and after repair. Pelvic MRIs were analyzed by a pediatric radiologist, and three-dimensional volumetric renderings of the true pelvis were calculated. Pre- and post-closure imaging were compared, in addition to imaging from age-matched controls without pelvic pathology. Cartilaginous acetabular index and version angles were also calculated and compared between groups. Eighteen patients with post-closure imaging, 14 of whom also had pre-closure imaging, and 23 control patients (ages 0-365 days) were included. The median ages at pre- and post-closure scan were 2 and 178 days, respectively. Osteotomy was performed in 6 (33%) of the closures. The median segmented pelvic volumes were 89cm3 in the pre-closure group, 105cm3 in the post-closure group, and 72cm3 in the control group. At a given age, patients with CBE pre-closure had the largest pelvic volume, and those without bladder exstrophy demonstrated the smallest pelvic volumes (Summary Figure). CBE patients' pelvic volumes were overall lower following repair, relative to age (p=0.007). Cartilaginous acetabular version angle increased following closure, with acetabular orientation converting from retroversion to anteversion in all cases. However, only acetabular version angles were significantly different between groups. This study found that pelvic volume significantly decreased relative to age following primary repair of CBE, but that it did not correct to control levels. Similarly, acetabular retroversion that is naturally seen in exstrophy patients was converted to anteversion post-closure but did not become completely normal. Knowledge of these persistent anatomical anomalies may be useful in treatment of future concerns related to exstrophy, such as continence achievement, pelvic organ prolapse, and potential gait disturbances. Lack of significant differences between study groups regarding acetabular index angles can give assurance to providers that hip dysplasia is neither a natural concern nor iatrogenically inflicted through reconstruction. The primary closure of exstrophy results in pelvic volumes and anteverted acetabula that more closely resemble those without bladder exstrophy, compared to pre-closure findings.

Role of 68-Ga-PSMA-PET/CT in pelvic radiotherapy field definitions for lymph node coverage in prostate cancer patients

PurposeTo evaluate the distribution of metastatic lymph nodes (LN) detected on 68Ga-PSMA-positron emission tomography/computed tomography (PET/CT) in treatment-naïve prostate cancer (PC) patients and to analyze the LN coverage rates of the pelvic fields defined in the GETUG trial and RTOG guidelines and a pelvic field extending superiorly from the L4/L5 interspace. Materials and methods68Ga-PSMA-PET/CT images obtained at diagnosis of 138 PC patients were retrospectively analyzed. The number and locations of 68Ga-PSMA-positive LNs were co-registered with one single-planning CT. The numbers, locations, and sizes of LNs located outside the three pelvic volumes were investigated for the entire cohort and for patients with LN metastasis in the pelvic area only. ResultsA total of 441 PSMA-PET-positive LN metastases were identified. The most frequent metastatic LNs were internal iliac LNs (25.2%). Para-aortic and presacral LNs outside the three pelvic fields were present in 20 (14.5%) and 22 patients (15.9%), respectively. The LN coverage rates according to the GETUG trial, the RTOG guidelines, and the pelvic field extending superiorly from L4/L5 were 44.2%, 52.2%, and 71, respectively, in the entire cohort and 51.7%, 61 and 83.1%, respectively, in patients with only pelvic LN metastasis. The number of metastatic LNs was a predictive factor for LNs located outside the three pelvic fields. ConclusionsExtending the cranial margin of the pelvic field from L5/S1 to L4/L5 increases the accuracy of pelvic field irradiation in approximately 20% of patients, highlighting the importance of proximal common iliac irradiation, particularly in patients with multiple LN metastasis.

NRG Oncology Updated International Consensus Atlas on Pelvic Lymph Node Volumes for Intact and Postoperative Prostate Cancer

In 2009, the Radiation Therapy Oncology Group (RTOG) genitourinary members published a consensus atlas for contouring prostate pelvic nodal clinical target volumes (CTVs). Data have emerged further informing nodal recurrence patterns. The objective of this study is to provide an updated prostate pelvic nodal consensus atlas. A literature review was performed abstracting data on nodal recurrence patterns. Data were presented to a panel of international experts, including radiation oncologists, radiologists, and urologists. After data review, participants contoured nodal CTVs on 3 cases: postoperative, intact node positive, and intact node negative. Radiation oncologist contours were analyzed qualitatively using count maps, which provided a visual assessment of controversial regions, and quantitatively analyzed using Sorensen-Dice similarity coefficients and Hausdorff distances compared with the 2009 RTOG atlas. Diagnostic radiologists generated a reference table outlining considerations for determining clinical node positivity. Eighteen radiation oncologists' contours (54 CTVs) were included. Two urologists' volumes were examined in a separate analysis. The mean CTV for the postoperative case was 302 cm3, intact node positive case was 409 cm3, and intact node negative case was 342 cm3. Compared with the original RTOG consensus, the mean Sorensen-Dice similarity coefficient for the postoperative case was 0.63 (standard deviation [SD] 0.13), the intact node positive case was 0.68 (SD 0.13), and the intact node negative case was 0.66 (SD 0.18). The mean Hausdorff distance (in cm) for the postoperative case was 0.24 (SD 0.13), the intact node positive case was 0.23 (SD 0.09), and intact node negative case was 0.33 (SD 0.24). Four regions of CTV controversy were identified, and consensus for each of these areas was reached. Discordance with the 2009 RTOG consensus atlas was seen in a group of experienced NRG Oncology and international genitourinary radiation oncologists. To address areas of variability and account for new data, an updated NRG Oncology consensus contour atlas was developed.

Retrospective audit of inter-fraction motion for pelvic node radiotherapy in prostate cancer patients

IntroductionPelvic lymph nodes move independently to the prostate. When delivering radiotherapy to prostate and pelvic lymph nodes, daily inter- and intra-fraction anatomical changes need to be accounted for. Planning target volume (PTV) margins, grown from the pelvic lymph node clinical target volume need to be determined, to account for this variation in position. MethodsTwenty patients who had daily online image guided radiotherapy to prostate and pelvic lymph nodes between April and December 2018 were selected. Ten pre-treatment verification images using cone beam CT from each patient were registered to pelvic bone anatomy, prostate soft tissue or fiducial markers and pelvic lymph node soft tissue to assess the accuracy of treatment delivery. Population systematic and random errors and PTV margins were calculated. ResultsPTV margins of 0.4 cm, 0.4 cm and 0.7 cm left–right (LR), superior–inferior (SI) and anterior–posterior (AP) respectively were derived for the pelvic lymph nodes when registering to prostate. PTV margins of 0.3 cm, 0.2 cm and 0.4 cm LR, SI and AP respectively were derived for the pelvic lymph nodes when registering to bone. There was a posterior systematic shift of the prostate during the treatment course. ConclusionThere is differential motion of pelvic lymph nodes to prostate and in the era of prostate and pelvic radiotherapy for patients with node positive prostate cancer; there is increasing importance in the accuracy of dose delivery to the involved lymph node. Hence, this group of patients may benefit from personalised radiotherapy PTV margins, especially if the involved pelvic lymph node is within the anterior part of the clinical target volume. Implications for practiceOptimisation of dose delivery to the pelvic lymph nodes when prioritising the prostate in prostate and pelvic lymph node image guided radiotherapy.

Quantitative CT measurement of left colonic and pelvic mesenteric adipose volume in radiation proctitis.

The edema of left colonic and pelvic mesenteric adipose tissues has long been recognized in surgery as a characteristic feature of radiation proctitis (RP). However, the correlation between mesenteric adipose volume and RP has not been extensively clarified. The purpose of this study was thus to assess the variation of left colonic and pelvic mesenteric adipose volume in RP. From March 2013 to June 2015, the data of 52 patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy, including 23 patients with RP and 29 with non-RP (nRP), were retrieved. The mesenteric adipose volume was quantified via a computed tomography (CT) reconstruction method. Corresponding analyses were conducted to observe the correlation between the relative change of mesenteric adipose volume and the thickening degree of the rectal wall. The baseline data of the RP group and the nRP group were comparable. There was no significant difference in the relative change of the left colonic mesenteric adipose volume in each vertebral space from the third lumbar vertebra to the first sacral vertebra before and after radiotherapy. The relative change of pelvic mesenteric adipose volume (ΔVp%) was notably higher in the RP group compared to the nRP group. With a ΔVp% cutoff value of 3.67%, the sensitivity and specificity for the diagnosis of RP were 65.2% and 86.2%, respectively. According to the correlation analysis, ΔVp% in the RP group was significantly correlated with the thickening degree of the rectal wall after radiotherapy (r=0.47, P=0.024). The increment of the relative change of pelvic mesenteric adipose volume quantitatively measured by CT can be clinically useful in identifying RP.