Background: Undifferentiated pleomorphic sarcoma (UPS) is the most common subtype of soft-tissue sarcoma (STS). At our institution, preoperative management typically consists of neoadjuvant chemotherapy plus radiotherapy (CT-RT) or radiotherapy (RT) alone. This study aimed to assess (1) the impact of treatment strategies on therapeutic response, and (2) the utility of multiparametric MRI (mp-MRI), qualitative and morphologic features from contrast-enhanced susceptibility-weighted imaging (CE-SWI) and dynamic contrast-enhanced perfusion-weighted imaging (PWI/DCE), for response evaluation. Methods: In this IRB-approved retrospective study, 36 UPS patients underwent presurgical mp-MRI between 02/2021 and 03/2025. Unlike our prior STS research, we intentionally excluded clinically unavailable software-based semiquantitative, quantitative, and radiomic analyses, focusing instead on morphologic and qualitative features readily accessible to clinical radiologists. Lesions were morphologically classified by CE-SWI-T2* and PWI/DCE in six patterns, respectively. PWI/DCE Time-intensity curves (TICs) types III—V, characterized by rapid arterial upstroke, were considered “aggressive,” while TIC I–II as non-aggressive. Patients with ≥90% pathology-assessed treatment effect (PATE) on the surgical specimen were designated as responders (n=20), >30 and <90% PATE as partial-responders (n=10), and ≤30% as non-responders (n=6). <90% patients were combined into a single group (partial/non-responders n=16). Results: Of 36 patients, 23 received CT-RT and 13 received RT alone. The CT-RT group demonstrated a higher responder rate (61% vs. 45%) and a higher mean PATE (81% vs. 66%; P=0.054) than the RT group. Among CT-RT responders, 86% showed a CE-SWI-complete-ring pattern (P=2.72×10⁻⁹), 86% a PWI/DCE-capsular-pattern (P=1.05×10⁻⁷), and 93% TIC-type-II (P=1.35×10⁻⁵). A predictive model combining PWI/DCE-capsular-enhancement, TIC-II, and favorable CE-SWI-patterns (“full blooming” or “complete ring”) achieved excellent performance (AUC=0.98) for distinguishing responders from non-responders, outperforming RECIST (AUC=0.52). In the RT group, all responders demonstrated TIC-II (P=0.014), and a model based solely on TIC-II achieved perfect classification (AUC=1.0). Conclusion: The CT-RT group shows a non-statistically significant higher proportion of responders and PATE-average than patients receiving RT-alone. MP-MRI-based predictive models using PWI/DCE and CE-SWI morphologic and qualitative clinically available features substantially outperform RECIST in predicting UPS pathology response. While the CT-RT model closely resembled a previously published treatment-agnostic UPS response model, pathology response in RT-alone patients was reliably predicted by the presence of presurgical TIC-II alone, indicating that optimal classification models for distinguishing responders vary by both tumor histology and treatment regimen, underscoring the importance of personalized imaging approaches.

Undifferentiated pleomorphic sarcoma (UPS) is the largest subgroup of soft-tissue sarcomas. It demonstrates post-therapeutic hemosiderin deposition, granulation tissue formation, fibrosis, and calcification. Our research aims to establish the multiparametric MRI (mp-MRI) value for predicting UPS treatment response. An IRB-approved retrospective study included 33 extremity UPS patients with pre-operative mp-MRI, including diffusion-weighted imaging (DWI), contrast-enhanced susceptibility-weighted imaging (CE-SWI), and perfusion-weighted imaging with dynamic contrast-enhancement (PWI/DCE), and surgical resection between February 2021 and May 2023. Lesions were visually classified on CE-SWI into one of 6 morphology patterns. On PWI/DCE, lesions were classified into one of 6 patterns, and time-intensity curves (TICs) were classified as types I-V. Patients were categorized into three groups based on the percentage of pathology-assessed treatment effect (PATE) in the surgical specimen: Responders (> = 90

PURPOSE Undifferentiated pleomorphic sarcomas (UPSs) demonstrate therapy-induced hemosiderin deposition, granulation tissue formation, fibrosis, and calcification. We aimed to determine the treatment-assessment value of morphologic tumoral hemorrhage patterns and first- and high-order radiomic features extracted from contrast-enhanced susceptibility-weighted imaging (CE-SWI). MATERIALS AND METHODS This retrospective institutional review board–authorized study included 33 patients with extremity UPS with magnetic resonance imaging and resection performed from February 2021 to May 2023. Volumetric tumor segmentation was obtained at baseline, postsystemic chemotherapy (PC), and postradiation therapy (PRT). The pathology-assessed treatment effect (PATE) in surgical specimens separated patients into responders (R; ≥90%, n = 16), partial responders (PR; 89%-31%, n = 10), and nonresponders (NR; ≤30%, n = 7). RECIST, WHO, and volume were assessed for all time points. CE-SWI T2* morphologic patterns and 107 radiomic features were analyzed. RESULTS A Complete-Ring (CR) pattern was observed in PRT in 71.4% of R ( P = 7.71 × 10 –6 ), an Incomplete-Ring pattern in 33.3% of PR ( P = .2751), and a Globular pattern in 50% of NR ( P = .1562). The first-order radiomic analysis from the CE-SWI intensity histogram outlined the values of the 10th and 90th percentiles and their skewness. R showed a 280% increase in 10th percentile voxels ( P = .061) and a 241% increase in skewness ( P = .0449) at PC. PR/NR showed a 690% increase in the 90th percentile voxels ( P = .03) at PC. Multiple high-order radiomic texture features observed at PRT discriminated better R versus PR/NR than the first-order features. CONCLUSION CE-SWI morphologic patterns strongly correlate with PATE. The CR morphology pattern was the most frequent in R and had the highest statistical association predicting response at PRT, easily recognized by a radiologist not requiring postprocessing software. It can potentially outperform size-based metrics, such as RECIST. The first- and high-order radiomic analysis found several features separating R versus PR/NR.

Desmoid tumors are rare mesenchymal neoplasms characterized by a clonal proliferation of fibroblasts and myofibroblasts. Using the novel contrast-enhanced susceptibility-weighted imaging (CE-SWI) for characterizing desmoid tumors can enhance the separation between fibrous T2-hypointense and cellular T1-enhancing components. We aim to evaluate the effectiveness of the CE-SWI signal, volumetric, and radiomics-derived features in assessing desmoid treatment response. This IRB-approved study included 17 single-lesion extremity desmoid fibromatosis patients who underwent standard-of-care MRI, including CE-SWI, from March 2021 to February 2024. Measurements of maximum diameter, volume, and the modified Choi (m-Choi: tumor/muscle T2 ratio) were computed based on CE-SWI and T2-STIR volumetric tumor segmentations. 107 shape, first-order, and textural radiomic features were calculated. Patient response was assessed using conventional RECIST as a reference standard and compared against T2-STIR and CE-SWI volumetric, m-Choi, and radiomics features. RECIST-progression (n = 3): In two patients, CE-SWI volume detected progression 10 months earlier than T2-STIR-based RECIST. Only 33% were characterized as progression by the routine radiologic report (RRR). RECIST-stability (n = 14): 5% exhibited at least one expected first-order response/progression-related change in the mean, skewness, 10th percentile, or 90th percentile, with all four changes present in 33% of cases. In RECIST-progression, CE-SWI showed an average of 15% more voxels at the 90th percentile than T2-STIR. Volume and CE-SWI/T2-STIR shape-derived size dimensional features demonstrated the highest separation between progressive and responding patients. CE-SWI has a higher sensitivity than T2-WI in detecting the active/progressive enhancing component. Volume and Shape-derived and, to a lesser extent, textural radiomic features and m-Choi effectively distinguish between progressive and responding cases, outperforming first-order radiomics, RRR, and RECIST. Particularly, progression prediction by CE-SWI/T2-STIR-volume and response prediction by CE-SWI-m-Choi outperform and precede RRR and RECIST. The novel CE-SWI enhances tumor insight and desmoid treatment-response prediction by effectively separating responding T2-hypointense-collagenized-mature components from potentially progressive T1-shortened/enhancing T2-hyperintense-immature components.

Bizarre, reactive fibroblastic proliferations associated with localized lymphedema may arise with chronic condom catheter use. We report a unique presentation of innumerable, cutaneous nodules occurring in chronic lymphedema of the right lower extremity due to remote pelvic lymph node dissection and radiation therapy for squamous carcinoma of the uterine cervix. Histologically, the cutaneous nodules consisted of several bizarre, enlarged polygonal to stellate, multinucleated fibroblasts having variably vacuolated cytoplasm in a background of markedly edematous dermis with prominent vascular ectasia. Nuclear hyperchromasia, scattered mitotic figures and pleomorphism in the context of chronic lymphedema led to an original diagnosis of malignancy. However, on histologic re-review, close correlation with imaging studies revealed complete continuity of massive subcutaneous lymphedema with the overlying skin nodules. The presence of diffuse reactive changes of edema and ectasia associated with multinucleated fibroblasts enables recognition of this pseudosarcomatous lesion. To our knowledge, this is the first report of extreme, multiple, cutaneous polypoid lesions comprising bizarre fibroblasts that simulate sarcoma and occur in the setting of chronic lymphedema. Awareness of this entity is critical, as it is easily misdiagnosed as sarcoma complicating lymphedema. We propose the descriptive term florid pseudosarcomatous polypoid fibroplasia for such extreme lesions.

Background and purpose: Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in the pediatric population and an aggressive cancer subtyped as embryonal, alveolar, pleomorphic, or not otherwise specified (NOS). It demonstrates post-therapeutic hemosiderin deposition, granulation tissue formation, fibrosis, and calcification. This pilot study aims to provide initial evidence for developing a multiparametric MRI-feature-derived (mp-MRI) predictive response model to outperform RECIST.Methods: A UT MD Anderson Cancer Center IRB-approved retrospective pilot study of 11 extremity and pelvic RMS patients with presurgical mp-MRI, including diffusion-weighted imaging (DWI), contrast-enhanced susceptibility-weighted imaging (CE-SWI), and perfusion-weighted imaging with dynamic-contrast-enhancement (PWI/DCE), with surgical resection between 02/2021-06/2024. Lesions were categorized into 6 CE-SWI and 6 PWI/DCE morphologic patterns. Time-intensity curves (TICs) were classified as types I-V. Patients were categorized by the percentage of pathology-assessed treatment effect (PATE) in the surgical specimen as responders (PATE> 90%, n = 3) and partial/non-responders (PATE < 90%, n = 8).Results: The ADC-mean for the 6 extremity RMS increased minimally from 1,425 ± 476 x 10-6 mm2/s at baseline (BL) to 1,494 ± 386 x 10-6 mm2/s at the presurgical time point (PS). The ADC-mean for the 5 pelvic RMS increased from 1,093 ± 342 x 10-6 mm2/s at BL to 1,677 ± 313 x 10-6 mm2/s at PS. All responders and partial/non-responders presented presurgical RECIST, WHO, and volume stability. At PS, 50% of responders displayed CE-SWI Complete Ring pattern (p = 0.5578), PWI/DCE Capsular pattern (p = 0.6065), and TIC Type-2 (p = 0.6065). No statistically significant differences were observed at PS in ADC or CE-SWI first- or high-order radiomics and PWI/DCE semi-quantitative parameters comparing responders vs. partial/non-responders at PS. PS ROC Analysis: The model based on the CE-SWI textural radiomic GLSZM Large-Area-High-Gray-Level-Emphasis yielded perfect classification performance (AUC = 1.0) separating responders vs. partial/non-responders, outperforming other radiomic, morphologic, and qualitative features such as ADC-Maximum-2D-Diameter-Slice (0.83), CE-SWI Complete Ring (AUC = 0.67), PWI/DCE Capsular (0.67), RECIST (0.67), and TIC type-2 (0.6).Conclusion: Our pilot study provides initial evidence supporting a model utilizing a single CE-SWI-derived high-order texture GLSZM radiomic feature that, in our small sample, obtained a perfect classification performance (AUC = 1.0), further building on the body of evidence supporting the use of mp-MRI with CE-SWI in soft-tissue sarcoma response assessment and suggesting its potential in predicting RMS response, outperforming RECIST (AUC = 0.67). These promising early results are hindered by a limited statistical power (10%) inherent to the small sample size and the retrospective nature of an exploratory pilot study, highlighting the necessity for further validation through a larger, more representative, and balanced prospective study.

Advanced MR imaging features of soft-tissue leiomyosarcoma (LMS) have not been reported, and no imaging biomarkers exist for response to neoadjuvant therapy (NAT). The exploratory study pilot aims to address these deficiencies and gather initial evidence supporting its utility. Nine patients with LMS and advanced MRI at the pre-operative time point comprised the study population. Patients were dichotomized into responders (those with a treatment effect of ≥90%) and partial/non-responders (those with a treatment effect of <90%) based on the pathology report. Custom software was used to measure lesions, derive volumetric radiomic features on contrast-enhanced susceptibility-weighted images (CE-SWI) and apparent diffusion coefficient (ADC) images, generate time-intensity curves (TICs), and estimate semi-quantitative perfusion variables. Imaging patterns were classified visually by the radiologists in consensus as aggressive vs. non-aggressive on CE-SWI, arterial phase perfusion images (PWI), and TICs. Fisher’s exact test was used to assess the association between these patterns and the response. At baseline, mean ADCmean was 1.28 × 10-3 mm2/s (95% CI: 0.843 - 1.72 × 10-3 mm2/s), and imaging patterns were all aggressive. No baseline features were predictive of response. At the preoperative time point, the non-aggressive CE-SWI pattern of “complete ring” was able to predict a response to NAT (odds ratio: 0.0, p = 0.018). CE-SWI radiomic analysis identified several predictive features. Receiver operating characteristic analysis of classification models based on CE-SWI and radiomic features on CE-SWI and ADC showed an AUC of 1. Our pilot study provides initial evidence on the use of advanced MRI features for characterizing treatment-naïve soft tissue LMS. Additionally, it supports the utility of advanced MRI features in determining treatment response on pre-operative/post-NAT scans, potentially outperforming all traditional size-based metrics.

Dysregulated FGF23 production is a demonstrated cause of hypophosphatemia and osteomalacia. Diseases associated with these conditions include phosphaturic mesenchymal tumor (PMT) causing tumor induced osteomalacia, various forms of rickets, and fibrous dysplasia (FD). Coexistence of 2 conditions that can increase FGF23 concentrations is rare. We report a case of a 79-yr-old man who presented with rib and right flank pain. Imaging revealed bone lesions in the right iliac wing, left supra-acetabular area, and L4 vertebral body. Biopsies showed a right iliac PMT and left supra-acetabular FD. Cryoablation of both lesions resolved the phosphaturia with normalization of phosphorus level. Coexistence of PMT and FD in this patient with hypophosphatemia raised questions about the source of the FGF23, meaning of coexistence of PMT and FD in the same patient and, about the nature of the third lesion in the L4 vertebral body. Using FGF23 mRNA chromogenic in situ hybridization, we identified the PMT, rather than the FD, as the source of FGF23. Lack of GNAS mutation in the PMT suggested it being independent of FD. Assessment by the intact FGF23: total FGF23 ratio as well as gallium-DOTATATE scan suggested that the vertebral body lesion could represent FD. Other than understanding difference in underlying molecular processing of FGF23 in PMT and FD, testing for mutations, imaging studies as well as in situ hybridization helped solve the questions arising from this unique case of coexistence of PMT and FD. We present a case of a male patient who presented with signs and symptoms of osteomalacia. Osteomalacia, meaning demineralization of the bones, has many causes. Chronic low phosphorus level due to increased urinary excretion is one of them. One of the substances that can cause excess excretion of phosphorus through kidneys, and hence, reduction in phosphorus level from blood circulation is an endocrine growth factor called FGF23. FGF23 is secreted by bone cells called osteoblasts and osteocytes under physiological state. Excess FGF23 secretion occurs in some pathological conditions. A type of musculoskeletal tumor called phosphaturic mesenchymal tumor is known to cause excess FGF23 secretion. Similarly, another skeletal disorder called fibrous dysplasia can cause excess FGF23 secretion too. Our patient had both of these conditions detected to be present simultaneously as different lesions in his bones. This case reports focuses on how understanding of FGF23 physiology and pathology helped us identify, out of the 2 different lesions, the exact source of excess FGF23 secretion. It also helped understand possible nature of another bone lesion that could not be examined by tissue exam.

PURPOSE Limitations from commercial software applications prevent the implementation of a robust and cost-efficient high-throughput cancer imaging radiomic feature extraction and perfusion analysis workflow. This study aimed to develop and validate a cancer research computational solution using open-source software for vendor- and sequence-neutral high-throughput image processing and feature extraction. METHODS The Cancer Radiomic and Perfusion Imaging (CARPI) automated framework is a Python-based software application that is vendor- and sequence-neutral. CARPI uses contour files generated using an application of the user's choice and performs automated radiomic feature extraction and perfusion analysis. This workflow solution was validated using two clinical data sets, one consisted of 40 pelvic chondrosarcomas and 42 sacral chordomas with a total of 82 patients, and a second data set consisted of 26 patients with undifferentiated pleomorphic sarcoma (UPS) imaged at multiple points during presurgical treatment. RESULTS Three hundred sixteen volumetric contour files were processed using CARPI. The application automatically extracted 107 radiomic features from multiple magnetic resonance imaging sequences and seven semiquantitative perfusion parameters from time-intensity curves. Statistically significant differences ( P < .00047) were found in 18 of 107 radiomic features in chordoma versus chondrosarcoma, including six first-order and 12 high-order features. In UPS postradiation, the apparent diffusion coefficient mean increased 41% in good responders ( P = .0017), while firstorder_10Percentile ( P = .0312) was statistically significant between good and partial/nonresponders. CONCLUSION The CARPI processing of two clinical validation data sets confirmed the software application's ability to differentiate between different types of tumors and help predict patient response to treatment on the basis of radiomic features. Benchmark comparison with five similar open-source solutions demonstrated the advantages of CARPI in the automated perfusion feature extraction, relational database generation, and graphic report export features, although lacking a user-friendly graphical user interface and predictive model building.

Routine radiologic reporting (RRR) often considers progressive desmoid tumors to have a higher proportion of T2-hyperintense and T1-shortened-enhancing components, while responsive or mature collagenized tumors demonstrate a higher proportion of T2-hypointense-non-enhancing components. We aim to determine the utility of the novel use of contrast-enhanced susceptibility-weighted imaging (CE-SWI) in Desmoid-Tumor treatment response assessment, distinguishing between the T1-shortening-enhancing/T2-hyperintense immature components from the T2-hypointense mature collagenized components. This pilot study included 10 single-lesion extremity desmoid fibromatosis patients undergoing standard-of-care magnetic resonance imaging, including CE-SWI. Three-dimensional (3D) tumor segmentation was performed using MIM software in 48 volumes of interest. Maximum diameter, volume, and modified Choi (mChoi) measurements were computed from CE-SWI and T2-weighted image (T2-WI). Five first-order radiomic features, including mean, skewness, kurtosis, and 10th and 90th percentiles, were calculated using in-house developed software (CARPI-AF). (i) RECIST Progression: We observed two cases of progression according to the T2-WI-based Response Evaluation Criteria in Solid Tumors standard (RECIST). Interestingly, CE-SWI-based-volume and CE-SWI-based-mChoi predicted the same assessment 4.5 months earlier than T2-WI-based-RECIST. RRR assessed both cases as progression; (ii) RECIST Stability: Out of the eight patients classified as having stable disease by T2-WI-based-RECIST, four discrepant progressions were determined: three patients showed an increase greater than 25% of T2-WI-based-volume, and two patients showed an increase greater than 25% of CE-SWI-based-volume. Moreover, from the RECIST stable group, four discrepant-positive responses were predicted by CE-SWI-based-mChoi (three patients) and T2-WI-based-mChoi (four patients). RRR only assessed one patient as having progressive disease; (iii) First-Order Radiomics: CE-SWI detected 23% more 90th-percentile voxels than T2-WI, while T2-WI demonstrated 8.5% more 10th-percentile voxels than CE-SWI. Notably, expected first-order response/progression-related changes in 10th-percentile, 90th-percentile, mean, and skewness were present in 90% of cases. In conclusion, CE-SWI-based-volume and CE-SWI-based-mChoi measurements could improve the prediction of response/progression in desmoid tumors, enhancing the ability in discriminating between T2*- hypointense-collagenized-mature and T1-shortened-enhancing immature components, respectively, in predominant mature responsive and immature progressive tumors, respectively. RRR is relatively insensitive to volumetric tumor changes before RECIST progression and tends to be better tuned with T2* signal and enhancement changes.

Soft-tissue sarcomas are a rare and complex group of malignant tumors. Advanced MRI sequences such as diffusion-weighted imaging (DWI) and perfusion-weighted imaging/dynamic contrast enhancement (PWI/DCE) can provide valuable tumor characterization and treatment response assessment. In the case of archetypical cellular tumors such as Pleomorphic Undifferentiated sarcoma (UPS), Good responders often display right-side displacement of the ADC intensity histogram, resulting in increased ADC-mean and decreased kurtosis and Skewness compared with Baseline and poor responders’ more left-sided curve. The PWI/DCE pattern most often associated with a good response is the presence of a “capsular-like” enhancement and a TIC type 2. Sarcoma hemorrhage patterns on SWI emerge during treatment, including “interstitial,” globular,” “luminal,” and incomplete and complete “peripheral ring-like” tumor wall hemosiderin impregnation. Treatment-induced bleeding is typically associated with low SWI-mean values and a left-sided intensity histogram with positive Skewness. During post-surgical surveillance, DCE MR imaging can reliably distinguish recurrent sarcoma from post-surgical scarring. TICs III, IV, and V raise the suspicion of local tumor recurrence, while TIC type II usually represents benign post-operative change such as granulation tissue. Advanced MRI is an essential tool for assessing sarcomas during and after therapy.

The assessment and subsequent management of a potentially neoplastic bone lesion seen at diagnostic radiography is often complicated by diagnostic uncertainty and inconsistent management recommendations. Appropriate clinical management should be directed by risk of malignancy. Herein, the ACR-sponsored Bone Reporting and Data System (Bone-RADS) Committee, consisting of academic leaders in the fields of musculoskeletal oncology imaging and orthopedic oncology, presents the novel Bone-RADS scoring system to aid in risk assignment and provide risk-aligned management suggestions. When viewed in the proper clinical context, a newly identified bone lesion can be risk stratified as having very low, low, intermediate, or high risk of malignancy. Radiographic features predictive of risk are reviewed include margination, pattern of periosteal reaction, depth of endosteal erosion, pathological fracture, and extra-osseous soft tissue mass. Other radiographic features predictive of histopathology are also briefly discussed. To apply the Bone-RADS scoring system to a potentially neoplastic bone lesion, radiographic features predictive of risk are each given a point value. Point values are summed to yield a point total, which can be translated to a Bone-RADS score (1-4) with corresponding risk assignment (very low, low, intermediate, high). For each score, evidence-based and best practice consensus management suggestions are outlined. Examples of each Bone-RADS scores are presented, and a standardized diagnostic radiography report template is provided.

Tumors of the uterine corpus include endometrial and mesenchymal tumors. Carcinoma of the endometrium is the most common female pelvic malignancy, the fourth most common cancer in women in the United States, and the sixth most common malignancy in women worldwide. This chapter summarizes important concepts regarding the pertinent anatomy, epidemiology, clinical presentation, staging, imaging evaluation, and treatment of these malignancies, which are essential to the successful multidisciplinary management of these patients. Imaging remains integral to the diagnosis, staging, and response assessment of these cancers, with the radiologist playing an essential role in patient care.

PURPOSE:Chondrosarcomas arise from the lateral pelvis; however, midline chondrosarcomas (10%) display similar imaging features to chordoma, causing a diagnostic challenge. This study aims to determine the diagnostic accuracy of apparent diffusion coefficient (ADC)-based radiomic features and two novel diffusion indices for differentiating sacral chordomas and chondrosarcomas. METHODS:A retrospective, multireader review was performed of 82 pelvic MRIs (42 chordomas and 40 chondrosarcomas) between December 2014 and September 2021, split into training (n = 69) and validation (n = 13) data sets. Lesions were segmented on a single slice from ADC maps. Eight first-order features (minimum, mean, median, and maximum ADC, standard deviation, skewness, kurtosis, and entropy) and two novel indices: restriction index (RI, proportion of lesions with restricted diffusion) and facilitation index (FI, proportion of lesions with facilitated diffusion) were estimated. One hundred seven radiomic features comparing patients with chondrosarcoma versus chordoma were sorted based on mean group differences. RESULTS:There was good to excellent interobserver reliability for eight of the 10 ADC metrics on the training data set. Significant differences were observed (P < .005) for RI, FI, median, mean, and skewness using the training data set. Optimal cutpoints for diagnosis of chordoma were RI > 0.015; FI < 0.25; mean ADC < 1.7 × 10-3 mm2/s; and skewness >0.177. The optimal decision tree relied on FI. In a secondary analysis, significant differences (P < .00047) in chondrosarcoma versus chordoma were found in 18 of 107 radiomic features, including six first-order and 12 high-order features. CONCLUSION:The novel ADC index, FI, in addition to ADC mean, skewness, and 12 high-order radiomic features, could help differentiate sacral chordomas from chondrosarcomas.

With the availability of current imaging modalities, radiology plays a major role in diagnosis, pretreatment staging, and posttreatment evaluation of musculoskeletal soft tissue tumors. It is essential that the appropriate use of these imaging modalities be understood, as each imaging modality has its advantages and limitations in the assessment of soft tissue tumors. Newer, advanced imaging techniques have further facilitated management of soft tissue sarcomas. This chapter provides a holistic view of specific roles in the oncology team consisting of radiologist, oncology physician, and oncology orthopedic surgeon in diagnosis, staging, treatment and management of patients with musculoskeletal soft tissue sarcomas.

Internal hemipelvectomy without reconstruction of the pelvis is a viable treatment for pelvic sarcoma; however, the time it takes to return to excellent function is quite variable. Some patients require greater time and rehabilitation than others. To determine if psoas muscle recovery is associated with changes in ambulatory function, we retrospectively evaluated psoas muscle size and limb-length discrepancy (LLD) before and after treatment and their correlation with objective functional outcomes. T1-weighted MR images were evaluated at three intervals for 12 pelvic sarcoma patients following interval hemipelvectomy without reconstruction. Correlations between the measured changes and improvements in Timed Up and Go test (TUG) and gait speed outcomes were assessed both independently and using a stepwise multivariate regression model. Increased ipsilesional psoas muscle size from three months postoperatively to latest follow-up was positively correlated with gait speed improvement (r = 0.66). LLD at three months postoperatively was negatively correlated with both TUG (r = -0.71) and gait speed (r = -0.61). This study suggests that psoas muscle strengthening and minimizing initial LLD will achieve the greatest improvements in ambulatory function. LLD and change in hip musculature remain substantial prognostic factors for achieving the best clinical outcomes after internal hemipelvectomy. Changes in psoas size were correlated with the amount of functional improvement. Several patients in this study did not return to their preoperative ipsilateral psoas size, indicating that monitoring changes in psoas size could be a beneficial rehabilitation strategy.

Liposarcoma is a commonly occurring soft tissue sarcoma that can be divided into 4 subtypes. Myxoid and round cell liposarcoma (MRCL) represent one of these subtypes and are classified together due to their shared chromosomal translocation. Histologic analysis of MRCL reveals a myxoid matrix with a delicate capillary network and dispersed lipoblasts. Varying degrees of round cell component are also observed, with greater amounts of round cells indicating a higher histologic grade and poorer prognosis. MRCL has a unique pattern of spread due to its initial tendency to spread to extrapulmonary sites. Additionally, skeletal metastases are frequently found in cases of MRCL. While various imaging techniques are used to visualize MRCL and metastases, magnetic resonance imaging is generally the preferred method. This article reviews the pathophysiology and imaging features of MRCL as well as the imaging characteristics, advantages, and drawbacks of multiple imaging modalities for visualizing bone metastases. (C) 2019 Elsevier Inc. All rights reserved.