Evaluation Of Soft Tissue Sarcomas Research Articles

The mitotic rate as a prognostic biomarker after preoperative radiotherapy for high-grade limb/trunk soft tissue sarcoma

PurposeCurrently there is no generally accepted standardized approach for the pathologic evaluation of soft tissue sarcoma (STS) histology appearance after preoperative radiotherapy (PORT). This study aimed to investigate the prognostic value of pathological appearance after PORT for patients with high-grade limb/trunk STS. MethodsA cohort of 116 patients with high-grade STS of the limb/trunk treated with PORT followed by resection were evaluated. Patient characteristics, imaging tumor morphology (size, volume), and histopathology (mitotic and necrosis rate, viable cell, hyalinization/fibrosis cytopathic effect) were reviewed and reassessed. Disease free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier method, and the hazard ratio was derived from Cox proportional hazard models. Two predictive nomograms were calculated based on significant predictors identified. ResultsThe 5-year DFS and OS were 52.9% and 70.3%, respectively. Tumor size before (HR:1.07, 95%CI: 1.01–1.14) and after PORT (HR:1.08, 95%CI: 1.01–1.14), tumor volume (HR:1.06, 95%CI: 1.01–1.12), mitotic rate after PORT (HR: 1.06, 95%CI: 1.02–1.11), mitotic rate change after PORT (HR:1.04, 95%CI:1.00–1.09) were independent risk factors for DFS. Tumor size before (HR:1.08, 95%CI: 1.03–1.14) and after PORT (HR:1.09, 95%CI: 1.04–1.15), tumor volume (HR:1.05, 95%CI: 1.01–1.09), mitotic rate after PORT (HR: 1.09, 95%CI: 1.04–1.13), mitotic rate change after PORT (HR:1.05, 95%CI:1.01–1.09) were independent risk factors for OS. The C-index of pathologic predictive nomogram based on mitotic rate for DFS and OS were 0.67 and 0.73, respectively. The C-index of morphology-pathology predictive nomogram for OS was 0.79. ConclusionTumor size before and after PORT, tumor volume, mitotic rate after PORT, mitotic rate change after PORT were independent risk factors for DFS and OS in high-grade STS patients treated with PORT. The mitotic rate, independent of tumor morphology, showed its potential as a prognostic biomarker for pathologic evaluation in patients treated with PORT.

Multiparametric Evaluation of Soft Tissue Sarcoma: Current Perspectives and Future Directions

Imaging plays an essential role in diagnosing and managing musculoskeletal soft tissue masses. It provides anatomic details and aids in the characterization and prognostication of tumors. Advanced imaging is also essential for assessing treatment response and post-treatment surveillance. Several novel imaging techniques are now available that provide additional functional and metabolic information about these tumors. This additional information may be used to predict the biological behavior of the tumors and effectively assess the treatment response for optimizing their management. This article focuses on multiparametric imaging evaluation of soft tissue masses with a discussion of advancements in the domains of ultrasound, MRI, and CT imaging and how these may be helpful in pre- and post-treatment assessment of soft tissue tumors. Current perspectives on the role of diffusion imaging, perfusion imaging, and MR spectroscopy have been highlighted, and future directions of metabolic imaging are briefly outlined. As these advances hold a promising role in the multidisciplinary management of soft tissue sarcomas, it is important for the radiologist to be familiar with the latest advances and developments in imaging soft tissue tumors.

Correlation of Clinical, Histopathological and Histomorphometric Features of Canine Soft Tissue Sarcomas

Soft-tissue sarcomas (STS) represent a heterogeneous group of tumours with similar histological characteristics and biological behaviour. This study aimed to describe the correlation between clinical, histopathological and histomorphometric features of STS in dogs. Medical records were reviewed to identify all dogs in which an STS was diagnosed between 2006-2017. Thirty cases were included, and tumour samples and medical records were recovered. Most of the dogs were mixed breed (40%) and 80% of the STS were located in the subcutaneous connective tissue. Histopathological classification showed that undifferentiated sarcoma (17%) and peripheral nerve sheath tumour (30%) were the most common STS. Grade I STS were obtained in 50% of cases (15/30), and grade II or III tumours compromised 43% (13/30) and 7% (2/30) respectively. The mitotic index ranged from zero to 26 (5.8 ± 7.5). Increased nucleus:cytoplasm ratio was moderately associated with higher tumour grade (p = 0.05; rS = 0.361) and mitotic index (p = 0.05; rS = 0.355), while the number of microvessels was positively correlated with degree of differentiation (p = 0.05; rS = 0.362) and nuclear pleomorphism (p = 0.036; rS = 0.384). Histomorphometry proved to be useful in the evaluation of STS, representing an additional tool correlated with well-established prognostic factors (histopathological grade, degree of differentiation, nuclear pleomorphism).

The Prognostic Value of DWI MRI in The Diagnosis Of Soft Tissue Sarcomas

Background: DWI is beneficial in evaluation of soft tissue sarcomas, thus improving the diagnostic accuracy, characterization and response to treatment.Purpose: The aim of this study was to evaluate the benefit of using quantitative diffusion weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping in the diagnosis of soft tissue sarcoma, with emphasis on its prognostic value. Patients and Methods: This study included 50 patients with pathologically proven soft tissue sarcoma. The DWI was obtained with 3 b values, including 0, 400, and 800 s/mm². Calculation of the ADC value of the lesion was done by placing the region of interest (ROI) to include the largest area of the lesion. ADC values were compared with the histopathology. Results: The most frequent site was thigh (48.0), followed by shoulder, forearm, arm and foot (8.0% for each). The most frequent pathology was synovial sarcoma (32.0%) followed by spindle cell sarcoma (28.0%) then liposarcoma (12.0%). 80% of lesions showed restricted diffusion. Median ADC value was 0.7 and ranged from 0.5 to 2.4. All patients underwent surgery. 48.0% of patients received chemotherapy and 52.0% received radiotherapy. 56.0% of patients showed recurrence. 44.0% showed metastasis. Mean follow up duration was 13 months with standard deviation of 5 months. Median ADC value was significantly higher in patients with no recurrence (0.9) compared to those with recurrence (0.7). P value was 0.016. Conclusion: DWI with ADC mapping of soft tissue sarcoma has additive role to anatomic sequences for lesion characterization and grading as well as treatment response.

Magnetic resonance imaging of soft tissue sarcoma: features related to prognosis.

Magnetic Resonance Imaging is a fundamental tool in the evaluation of soft tissue sarcoma. Imaging features are relevant for the assessment of treatment strategies, surgical planning and also for patients' prognosis prediction. Among soft tissue sarcoma and also other malignancies, the size of the mass is usually considered the prognostic key element in diagnostic imaging. Moreover, several other features should be obtained from MRI studies with prognostic implications in all type of soft tissue sarcoma: peritumoral enhancement, signs of necrosis, deep location, ill-defined borders/signs of infiltrations. Focusing on soft tissue sarcoma subtypes, some other magnetic resonance imaging features are more specific and related to prognosis. In myxofibrosarcoma the magnetic resonance imaging "tail sign" and a "water-like" appearance on fluid-sensitive sequences, due to rich myxoid matrix content, are both associated with higher risk of local recurrence after surgical excision; nevertheless, the "tail sign" is also related to a higher risk of distant metastases at diagnosis. The "tail sign" is associated with higher risk of local recurrence after surgical excision in undifferentiated pleomorphic sarcoma as well. In patients affected by synovial sarcoma, the "triple sign" identifiable in magnetic resonance imaging (T2w sequences) is associated with decreased disease-free survival and indicates the simultaneous presence of solid cellular elements (intermediate signal intensity), hemorrhage or necrosis (high signal intensity) and fibrotic regions (low signal intensity).In addition, absence of calcifications are associated with reduced disease-free survival in patients affected by synovial sarcoma.Signal heterogeneity is associated with worst prognosis in all type of soft tissue sarcoma, particularly in myxoid liposarcoma. In recent years, several new quantitative tools applied on magnetic resonance imaging have been proved to predict patients' prognosis. Above all the new tools, radiomics seems to be one of the most promising, and, has been proved to have the capability in discriminating low-grade from high-grade soft tissue sarcomas. Therefore, magnetic resonance imaging studies in patients with soft tissue sarcoma should be accurately evaluated and their results should be taken into account for prognostic assessment.

The importance of diffusion apparent diffusion coefficient values in the evaluation of soft tissue sarcomas after treatment.

PurposeIn our study, we aimed to show the efficiency of diffusion-weighted images at different b-values and apparent diffusion coefficient (ADC) values in the differentiation of recurrent tumours from post-treatment tissue changes.Material and methodsThe conventional and diffusion magnetic resonance images (MRIs) of 42 patients operated for soft tissue sarcomas between June 2012 and March 2015 followed up with MRIs that were evaluated by 2 radiologists retrospectively. Diffusion MRIs were acquired at 4 different b-values (50, 400, 800, 1000 s/mm2). The lesions were classified according to conventional MRI findings as post-treatment changes and recurrent tumours.ResultsWhen the patient group with recurrent tumours was compared with the patient group with postoperative changes the ADC calculations were statistically significantly lower for the recurrent tumours at all b-levels (p < 0.001 for all b-levels). The sensitivity of b-50 values lower than 3.01 × 103 mm2/s in showing recurrent tumours was 100% and the specificity was 77.78%. The sensitivity of b-400 values lower than 2.1 × 103 mm2/s in showing recurrent tumours was 80% and the specificity was 96.3%. The sensitivity of b-800 values lower than 2.26 × 103 mm2/s in showing recurrent tumours was 100% and the specificity was 88.89%. The sensitivity of b-1000 values lower than 2 × 103 mm2/s in showing recurrent tumours was 93.3% and the specificity was 92.5%.ConclusionsThe ADC values obtained from diffusion-weighted images have high sensitivity and specificity in differentiating recurring soft tissue sarcomas during monitoring after treatment from postoperative changes.

Diagnostic and Clinical Impact of 18F-FDG PET/CT in Staging and Restaging Soft-Tissue Sarcomas of the Extremities and Trunk: Mono-Institutional Retrospective Study of a Sarcoma Referral Center.

Background: Soft-tissue sarcomas (STS) represent a wide heterogeneous class of rare tumors. The exact role 18F-fluorodeoxyglucose positron emission/computed tomography (18F-FDG PET/CT) in the evaluation of STS is not well established. The aim of the present study was to evaluate how the use of 18F-FDG PET/CT in STS could influence patient therapy planning, looking for a possible added value over computed tomography and magnetic resonance imaging—the most used modalities in the study of STS. Differences in SUVmax according to histologic subtype and tumor grade were also considered. Methods: a total of 345 consecutive 18F-FDG PET/CT scans performed for initial staging (n = 171) or for suspected disease relapse (n = 174) in 282 patients with STS extracted from the local Information System database were retrospectively reviewed. Results: 18F-FDG PET/CT altered therapy planning in 80 cases (16.4% for staging and 29.9% in restaging), both for disease upstaging (58.8%) and downstaging (41.2%) Conclusions: 18F-FDG PET/CT could significantly influence management of patients with STS, particularly for restaging.

Soft tissue sarcomas: Evaluation by immunohistochemistry

Soft tissue sarcomas represent a histologically heterogenous group of malignant tumors arising from the soft tissue compartments, i.e smooth muscles, skeletal muscles, adipose tissue, blood vessels, connective tissue mesenchyme, neural tissue and other tumors of uncertain histogenesis(1). Soft tissue sarcomas are relatively rare tumors, represent less than 1% of adult malignancies based on data report from American Cancer Society (2). The crude incidence rate in Iraq for soft tissue sarcomas was 219/ 100,000 population during 2014 with male: female ratio of 1.3:1, and highest peak age between 30-34 years (3). The histological subtype and microscopic criteria are two parameters that influence the tumor grade which is the best predictor for aggressiveness. ( 2)&#x0D; Objectives:&#x0D; A retrospective evaluation of soft tissue sarcomas, using immunohistochemical study of Myosin, Desmin, Smooth muscle Actin (SMA) and Vimentin, aiming to re-evaluate the primary diagnosis and whether IHC assessment in soft tissue sarcoma is mandatory to reach a final interpretation.&#x0D; Material and Patients: &#x0D; A total of 50 cases soft tissue sarcomas were reviewed retrospectively from case archives of histopathology department/ Central Public Health Laboratory, for the period (2011-2018). The data for these cases were collected including the age, gender, site of the tumor and the preliminary biopsy report findings. Hematoxylin&amp; Eosin (H&amp;E) stain and IHC staining of unstained sections from formalin-fixed, paraffin-embedded tissue were performed using SMA, Vimentin, Desmin and Myosin.&#x0D; Methods: Age and gender distribution of the 50 cases was correlated. The IHC staining performed on 5 microns paraffin sections, applying peroxidase-Antiperoxidase technique and both positive and negative control slides were included for Smooth muscle actin (SMA), clone 1A4, Desmin (clone D33), Myosin (clone 2F12.A9) and Vimentin (Clone V9). The monoclonal antibodies used were from DAKO manufacturer as ready to use monoclonal antibodies while freeze-dried antibodies used for myosin with 1:20 dilution. Negative and positive control slides were used simultaneously. The staining intensity was assessed based on the percentage of positive cells expression of the four IHC monoclonal antibodies. Negative staining reported when no stain seen. Positive (+) means up to 30% of tumor cells with antigen expression. Positive (++) interpretation given when 31-60% of tumor cells show staining reaction, while Positive (+++) interpretation reported when over 60% of tumor cells showing staining reaction.&#x0D; Results:&#x0D; The staining interpretation of the four monoclonal antibodies were confirmatory for the original diagnosis in 40% of cases, while 60% of the final diagnoses were against the original interpretation. SMA was positive in 38/50 cases (76%). Desmin was positive in 8/50 cases (20%) Vimentin was positive in 42/50 of cases (84%), Myosin was positive in 30/50 of cases (71.4%).&#x0D; The current study focus on histological re-evaluation of different types of soft tissue sarcomas (including RMS-with its subtypes), MFH-storiform, pleomorphic and myxoid subtypes), fibrosarcoma, leiomyosarcoma, alveolar soft part sarcoma and synovial sarcoma depending on immunohistochemical study. The original diagnosis have been changed after the immunohistochemistry stain from fibrosarcoma to rhabdomyosarcoma and leiomyosarcoma , Malignant fibrous histiocytoma to rhabdomyosarcoma, alveolar rhabdomyosarcoma to Malignant fibrous histiocytoma, soft tissue sarcoma to rhabdomyosarcoma , pleomorphic MFH to pleomorphic rhabdomyosarcoma. Embryonal and alveolar rhabdomyosarcoma were confirmed by IHC as so. Leiomyosarcoma was confirmed as the same in one case. Embryonal Rhabdomyosarcoma changed to leiomyosarcoma by IHC positivity for desmin. Six cases of MFH were confirmed as malignant fibrous histiocytoma after IHC. Two cases of synovial sarcoma were re-evaluated as rhabdomyosarcoma. Vimentin revealed 100% positivity in 10 cases and regarded as a sensitive marker for mesenchymal tissue but it is not specific for certain types of sarcomas. The presence of desmin diffusely throughout a tumor is an indication of myoid differentiation and the presence of either SMA or desmin focally should not necessarily be equated with myoid lineage but rather with myofibroblastic lineage, which go in the same direction with Hirofumi N. et al. (1998).(4)&#x0D; Conclusions: The co-expression of SMA and Desmin helped in the diagnosis of leiomyosarcoma (LMS). Myosin expression was helpful in the diagnosis of rhabdomyosarcoma (RMS) and alveolar soft part sarcoma (ASPS). Smooth muscle actin (SMA) and vimentin were not specific for the diagnosis of malignant fibrous histiocytoma (MFH). High grade spindle cell sarcoma express SMA only without myosin or desmin can be categorized as pleomorphic myogenic sarcoma. By applying immunohistochemical markers, 60% of soft tissue sarcomas were different from the preliminary diagnosis while 40% of cases were supportive of the original H&amp;E diagnosis.

Pathologic Evaluation of Soft Tissue Sarcoma

Soft tissue sarcomas are rare tumors and are mostly managed in tertiary care centers. They are broadly classified based on their differentiation into multiple different types. They affect patients of all ages and mostly occur in the extremities. Pathologic examination of the biopsy or resection of the tumor is an extremely important aspect in the diagnosis of these tumors and appropriately guiding the clinical team in the management of these rare tumors. This review focuses on the aspects of pathologic evaluation of these tumors and discusses the morphologic aspects of the predominant soft tissue sarcomas based on differentiation. The review also highlights the latest molecular diagnostic studies that are used in the accurate subtyping of these tumors. This review contains 12 figures, 2 tables, and 28 references. Key words: angiosarcoma, fibromatosis, fibrous, liposarcoma, myxoid, nerve sheath tumor, sarcoma, synovial sarcoma

Pathologic Evaluation of Soft Tissue Sarcoma

Soft tissue sarcomas are rare tumors and are mostly managed in tertiary care centers. They are broadly classified based on their differentiation into multiple different types. They affect patients of all ages and mostly occur in the extremities. Pathologic examination of the biopsy or resection of the tumor is an extremely important aspect in the diagnosis of these tumors and appropriately guiding the clinical team in the management of these rare tumors. This review focuses on the aspects of pathologic evaluation of these tumors and discusses the morphologic aspects of the predominant soft tissue sarcomas based on differentiation. The review also highlights the latest molecular diagnostic studies that are used in the accurate subtyping of these tumors. This review contains 12 figures, 2 tables, and 28 references. Key words: angiosarcoma, fibromatosis, fibrous, liposarcoma, myxoid, nerve sheath tumor, sarcoma, synovial sarcoma

Evaluation of response after pre-operative radiotherapy in soft tissue sarcomas; the European Organisation for Research and Treatment of Cancer – Soft Tissue and Bone Sarcoma Group (EORTC – STBSG) and Imaging Group recommendations for radiological examination and reporting with an emphasis on magnetic resonance imaging

At present, there is no standardised approach for the radiological evaluation of soft tissue sarcomas following radiotherapy (RT). This manuscript, produced by a European Organisation for Research and Treatment of Cancer – Soft Tissue and Bone Sarcoma Group (EORTC – STBSG) and Imaging Group endorsed task force, aims to propose standardisation of magnetic resonance imaging techniques and interpretation after neoadjuvant RT for routine use and within clinical trials.

PET/MRI for Preoperative Planning in Patients with Soft Tissue Sarcoma: A Technical Report of Two Patients

Clinical positron emission tomography (PET)/magnetic resonance imaging (MRI) acquisition protocols may improve the evaluation of soft tissue sarcomas (STS) prior to surgical planning. We examined two patients with lower extremity STS using a Siemens Biograph mMR PET/MRI scanner and the glucose analogue 18F-fluoro-deoxyglucose (FDG). We investigated clinically relevant tumor volumes and evaluated the relations to skeletal periosteum and nerve bundles. The patient scans suggest that FDG PET/MRI improved the edge detection, and invasion of tumor tissue into important adjacent anatomical structures can be evaluated. FDG PET/MRI also provided additional information compared to conventional Gadolinium enhanced MR imaging. The findings were proven by subsequent pathological examination of the resected tumor tissue. In the future, clinical FDG PET/MRI may be an important modality for preoperative planning, including radiation therapy planning in patients with STS.

Magnetic resonance imaging and positron emission tomography-computed tomography evaluation of soft tissue sarcoma with surgical and histopathological correlation

Purpose:The aim of this study was to evaluate the role of positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) in characterization and pre-operative staging of soft-tissue sarcoma (STS) and correlating with operative and histopathological findings.Materials and Methods:Twenty patients (age range 16-72 years [mean 44.4 years]) with resectable and STS were included in this prospective study. Pre-operative MRI was carried out in all patients with acquisition of T1W, T2W, and short tau inversion recovery (STIR) sequences in appropriate planes. Contrast enhanced MRI was performed in four patients. Whole body PET-CT was performed in 13 patients. Demographic data, clinical features, pre-operative imaging analysis, operative, and histopathological findings were analyzed using SPSS software version 11.5.Results:The most common histologic type was malignant fibrous histiocytoma (MFH) (30%). Of 18 STSs 20 were high-grade. Agreement existed between MR and operative size. MRI had 100% negative predictive value (NPV) in predicting neurovascular bundle involvement. However, positive predictive value (PPV) was 33%. MRI had PPV of 20% while PET-CT had 50% PPV in detecting lymph node involvement. Overall staging accuracy of MRI was 75% when correlated with surgical and histopathological findings. Combined PET-CT and MRI staging, in 13 patients, was better (92.31%) when compared with staging with MRI (84.62%). Specific diagnosis on image characteristics was correctly suggested in 35% patients.Conclusions:MRI is the robust modality in local staging of STSs and PET-CT adds greater accuracy to overall staging in combination with MRI.

MRI evaluation of soft tissue sarcomas

e21523 Background: Althouth soft tissue constitute large part of the body, STS are rare (1% of all neoplasms) and can arise anywhere in the body. Imaging is require to confirm the diagnosis and for staging. We conducted a prospective study to evaluate the role of MRI scan in characterization and staging of the tumor. Methods: This study between 2006 and 2008 included 20 patients with histologically proven soft tissue sarcoma in whom preoperative MRI of the local site was performed and the findings were correlated with the surgical and histopathological findings. Only those patients in whom surgical and histopathological findings were available were included in the study. All MRI were performed on 1.5 T MRI using body and appropriate surface coil. T1W, T2W, and STIR sequences were acquired in axial, coronal, and sagittal planes. Contrast enhanced MRI was performed in four patients. Surgical findings were recorded by the operating surgeon and resected specimens were analyzed by pathologist for assessing extent and histologic typing. All demographic data of the patient, the clinical features, preoperative imaging analysis, operative and histopathological findings were tabulated as per the given proforma. Results: Age of the patients was 16 - 72 years (mean age 44.4 years). Male female ratio was 2.3:1 . Eleven cases were recurrent. Most common histologic type was MFH (30%) while synovial sarcoma was second most common (20%) type of the STS in our study. Eighteen of 20 soft tissue sarcomas were of high grade. Average size on MRI was 9.25 cm (range) and operative size was 9.8 cm (range). Statistically significant agreement existed between MR and operative size. The sensitivity of MRI for individual muscle involvement was 92.3% and specificity was 96.5%. MRI had a sensitivity of 93% and specificity of 100% in predicting fascial involvement. MRI had 100% sensitivity and specificity in showing skin and subcutaneous tissue involvement. MRI had 100% negative predictive value in predicting NV bundle involvement. None of the patients had bone or joint involvement. No distant parenchymal metastases were seen. Specific diagnosis based on MRI image characteristics was suggested in 35% patients. Conclusions: Overall staging accuracy of MRI was 75% in staging of STS when correlated with surgical and histopathological MSKCC staging. No significant financial relationships to disclose.

The Diagnostic Utility of Fine-Needle Aspiration Biopsy of Soft-Tissue Sarcomas in the Core Needle Biopsy Era

Abstract: Fine-needle aspiration biopsy (FNAB) is a widely accepted and established diagnostic technique in diagnosing the presence of primary malignancies, metastatic disease, and benign nonneoplastic lesions. However, its role in the evaluation of soft-tissue sarcomas has remained controversial, especially as the primary modality for establishing an initial diagnosis. Arguments in favor of using core needle biopsies (CNB) relate to the fact that such samples provide ample “tissue” for evaluating architectural patterns, as well as a source for performing ancillary studies. However, in the hands of experienced cytopathologists, FNAB in conjunction with ancillary studies (performed on tissue obtained in the form of cell blocks) has been shown to have a diagnostic yield nearly identical to CNB, with an accuracy rate approaching 95% for the diagnosis of malignancy. Additionally, as therapy and prognosis are heavily dependent on the grade and stage of the tumor, it has been shown that approximately 90% of soft-tissue sarcomas can be successfully subtyped and even graded by FNAB. There are, however, certain limitations of FNAB, especially in the workup of low-grade myxoid and spindle cell sarcomas and in their separation from borderline and benign lesions. In these select subgroups, CNB may be more advantageous. Also, in the absence of an on-site cytopathologist for immediate evaluation of the sample and triage of materials for ancillary studies, CNB is preferred, although FNAB can still identify benign soft-tissue lesions and malignancies of nonmesenchymal origin not requiring ancillary studies. This review will focus on the more commonly encountered soft-tissue sarcomas and highlight the advantages and limitations of FNAB in establishing their diagnosis.

Positron emission tomography of soft tissue sarcomas.

The purpose of this review is to underscore the value of positron emission tomography (PET) in the management of patients with soft tissue sarcomas. Although the most essential step in the diagnostic evaluation of soft tissue sarcomas is tumor biopsy, functional imaging techniques is growing and becoming more popular than before. PET scan traces molecular and cellular activities of normal and tumor cells through the use of radiotracers that engage in cell metabolism. The most important and widely used tracer is fluorodeoxyglucose (18FDG). PET scan usefulness is not limited to its ability to differentiate benign from malignant lesions. The scan can detect intralesional morphologic variation which is especially true in soft tissue sarcomas, it can predict tumor grade, and it is of value in staging, restaging and prognosis. As for the time, PET is not meant to replace tissue biopsy but rather complement the biopsy to better understand the biological behavior of soft tissue sarcomas.

Imaging of soft-tissue sarcomas.

A multidisciplinary approach that includes active participation by a radiologist is beneficial for optimal diagnostic evaluation and treatment of soft-tissue sarcomas. Recent advances in diagnostic imaging include a better understanding of the practical roles of ultrasonography, computed tomography, and magnetic resonance imaging in the evaluation of primary and recurrent soft-tissue sarcomas. The potential role of positron emission tomography scanning and dynamic magnetic resonance imaging in the evaluation of soft-tissue sarcomas has been preliminarily evaluated. The clinically practical utility of radiologic imaging in the evaluation of soft-tissue sarcomas is discussed, and ongoing research is briefly reviewed.

Optimal radiologic imaging of soft tissue sarcomas.

Radiologic evaluation of the patient with soft tissue sarcoma may include conventional radiography, scintigraphy, ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. The radiologist also plays a critical role in the evaluation of the patient with soft tissue sarcoma by guiding and performing aspiration biopsies. This review discusses the use of radiological techniques to evaluate the primary lesion and to detect recurrences. In adults, soft tissue sarcoma most commonly occurs in the extremities, and this review emphasizes the role of MR imaging in the pre- and post-treatment evaluation of extremity soft tissue sarcomas. The role of imaging studies in the evaluation of soft tissue sarcomas in the abdomen, thorax, and the head and neck region is also discussed.

Diagnostic procedures and pretreatment evaluation of soft tissue sarcomas.

The diagnosis and preoperative evaluation of patients with a suspected soft tissue sarcoma involve several important considerations to ensure optimal treatment outcomes. Biopsy techniques must involve the retrieval of adequate tissue to establish the histologic diagnosis and grade of the tumor without compromising the subsequent definitive surgical resection. CT or MRI techniques represent the gold standard to evaluate the local extent of disease which is necessary to ascertain surgical resectability and/or the need for radiation therapy. CT scanning of the lungs is mandated for all patients with sarcomas to evaluate for metastatic disease and, for patients with abdominal or retroperitoneal tumors, scanning of the liver should also be included. Accurate staging of these patients will help define overall survival.

Sonographic evaluation of soft tissue sarcomas (STS') local recurrence

Sonographic evaluation of soft tissue sarcomas (STS') local recurrence