Takayuki Aoyagi

Venous thromboembolism in the management of patients with musculoskeletal tumor

BackgroundAlthough patients with musculoskeletal tumors are at risk of venous thromboembolism (VTE), few detailed studies on the incidence, clinical course, and risk factors of this condition have been reported.MethodsA total of 299 patients with musculoskeletal tumors during the preceding 3 years were enrolled. D-dimer (DD) levels on admission and on postoperative days 1, 7, and 14 were routinely assessed. For patients who were receiving chemotherapy, an examination was performed every 2-3 days for the survey. Multidetector-row computed tomography (MDCT) was used for the detection of VTE in patients with DD levels > 10 μg/ml. The incidence of clinically detected VTE and the clinical courses of the patients with VTE were reviewed. The risk factors for VTE were analyzed. For statistical analysis, Fisher’s exact test, the Mann-Whitney U-test, and logistic regression were used.ResultsVTE was detected in eight cases (2.7%). Six cases were detected postoperatively, and the remaining two cases were detected during chemotherapy. Pulmonary embolism was evident in four cases. No VTE-related lethal events were detected during the study period. In the univariate analysis, malignancy (P = 0.003), chemotherapy (P = 0.004), plastic surgery (P = 0.006), tumor size (P = 0.008), and elevated DD levels at admission (P = 0.03) were found to be significant risk factors for VTE. Among these factors, the multivariate analysis indicated that tumor size (P = 0.00 006), plastic surgery (P 0. 01), and chemotherapy (P = 0.02) were independent risk factors.ConclusionsThe incidence and risk factors for VTE in the management of musculoskeletal tumor patients by screening DD levels combined with MDCT were analyzed. For patients at risk, prospective surveys for VTE should be considered in the future.

Preoperative ultrasonographic evaluation for malignancy of soft-tissue sarcoma: A retrospective study

Background: Ultrasonography is useful for distinguishing between benign and malignant soft-tissue tumors. However, no study has focused on its usefulness in the differential diagnosis between low-grade and high-grade soft-tissue sarcomas. We conducted a retrospective study to determine the usefulness of the parameters of ultrasonograph and to develop a practical scoring system for distinguishing between high-grade and low-grade sarcomas. Methods: Twenty-two cases of low-grade and 43 cases of high-grade malignant soft-tissue sarcoma were enrolled. Ultrasonography parameters including the longest diameter, depth of the tumor, echogenicity, tumor margin, and vascularity defined according to Giovagnorio’s criteria were analyzed as factors to distinguish between the two types of sarcoma. Significant factors were entered into a multivariate model to define the scores for distinction according to the odds ratio. The usefulness of the score was analyzed via receiver operating characteristic analyses. Results: In univariate analysis, tumor margin, echogenicity, and vascularity were significantly different between low- and high-grade sarcomas. In the multivariate regression model, the odds ratio for high-grade vs. low-grade sarcoma was 8.8 for tumor margin, 69 for echogenicity, and 8.3 for vascularity. Scores for the risk factors were defined as follows: 1, ill-defined margin; 2, hypoechoic echogenicity; and 1, type IV in Giovagnorio’s criteria. The sum of each score was confirmed by receiver operating characteristic analysis. The area under the curve was 0.95, with a cut-off score of 3, indicating that the scoring system was useful. Conclusion: The ultrasonography parameters of tumor margin, echogenicity, and vascularity are useful for distinguishing between low- and high-grade sarcomas.

Preoperative evaluation of intraoperative blood loss during malignant soft tissue tumor resection by ultrasonography

BACKGROUND Preoperative evaluation of the risk of surgery-related blood loss in malignant soft tissue tumor resection is difficult because of wide variations in histological subtype, malignancy, location, and size. Ultrasonography is useful for the evaluation of blood flow around a soft tissue tumor and has the potential to preoperatively estimate intraoperative blood loss in tumor resection. To date, there has been no report regarding blood loss evaluation using ultrasonography in this field. PATIENTS AND METHODS The usefulness of information obtained by ultrasonography, including tumor size, vessel density in the tumor, and blood flow volume in the vessels, was analyzed for the prediction of intraoperative blood loss in malignant soft tissue tumor resection. RESULTS Vessel density in the tumor and blood flow in the vessels were identified as independent risk factors for blood loss. Using these factors, a new index for the prediction of blood loss was established. Receiver operating characteristic analyses revealed a high area under the curve value (0.80), confirming the accuracy of the index for the prediction of blood loss. CONCLUSION Ultrasonography is a useful modality for predicting intraoperative blood loss in malignant soft tissue tumor surgery.

Differential diagnosis between benign and malignant soft tissue tumors utilizing ultrasound parameters

PurposePreoperative discrimination between benign and malignant soft tissue tumors is critical for the prevention of excess application of magnetic resonance imaging and biopsy as well as unplanned resection. Although ultrasound, including power Doppler imaging, is an easy, noninvasive, and cost-effective modality for screening soft tissue tumors, few studies have investigated reliable discrimination between benign and malignant soft tissue tumors.MethodsTo establish a modality for discrimination between benign and malignant soft tissue tumors using ultrasound, we extracted the significant risk factors for malignancy based on ultrasound information from 40 malignant and 56 benign pathologically diagnosed soft tissue tumors and established a scoring system based on these risk factors.ResultsThe maximum size, tumor margin, and vascularity evaluated using ultrasound were extracted as significant risk factors. Using the odds ratio from a multivariate regression model, a scoring system was established. Receiver operating characteristic analyses revealed a high area under the curve value (0.85), confirming the accuracy of the scoring system.ConclusionUltrasound is a useful modality for establishing the differential diagnosis between benign and malignant soft tissue tumors.