Resolution of ultrasonography (US) has undergone marked development. Additionally, a new-generation contrast medium (Sonazoid) used for US is newly available. Contrast-enhanced US has been widely used for evaluating several types of cancer. In the present study, we evaluated the ability of color Doppler US (CDUS) and Sonazoid to differentiate between benign and malignant soft tissue tumors. A total of 180 patients (87 male, 93 female) were enrolled in the present study. The patient ages ranged from 1 to 91 years (mean 58.1±20.0 years). The maximum size, depth, tumor margins, shape, echogenicity and textural pattern were measured on gray-scale images. CDUS was used to evaluate the intratumoral blood flow with and without Sonazoid. Peak systolic flow velocity (Vp), mean flow velocity (Vm), resistivity index (RI) and pulsatility index (PI) of each detected intratumoral artery were automatically calculated with power Doppler US (PDUS). The present study included 118 benign and 62 malignant tumors. Statistical significances were found in size, depth, tumor margin and textural pattern but not in shape or echogenicity on gray-scale images. Before Sonazoid injection, CDUS findings showed 55% sensitivity, 77% specificity and 69% accuracy, whereas contrast-enhanced CDUS showed 87% sensitivity, 68% specificity and 74% accuracy. There were no statistically significant differences between malignant and benign tumors regarding the mean Vp, Vm, RI and PI values determined on PDUS. In conclusion, contrast-enhanced CDUS proved to be a reliable diagnostic tool for detecting malignant potential in soft tissue tumors.

Treatment options for metastatic osteosarcoma are limited. The present study aimed to evaluate whether radiofrequency ablation (RFA) combined with intratumoural OK-432 injection induces systemic anti-tumour immunity in rat osteosarcoma model. Eighty of 145 rats were assigned to four groups to evaluate overall survival and tumour size: control (no treatment), RFA-only, OK-432, and RFA-OK-432. The remaining 65 were assigned for histological examination. Maximum diameters of tibial and lung tumours were determined. Tumour samples were histologically examined using haematoxylin-eosin and immunohistochemical staining. Overall survival was significantly prolonged in the RFA-OK-432 group compared to the RFA-only and OK-432 groups. Only rats in the RFA-OK-432 group exhibited significant decreases in maximum tumour diameter after treatment. Ki-67-positive tumour cells in the RFA-OK-432 group were significantly stained negative on immunohistochemical analysis as opposed to those in the RFA-only and OK-432 groups. The number of CD11c+, OX-62+, CD4+, and CD8 + cells significantly increased in the RFA-OK-432 group compared to the RFA-only group. RFA with intratumoural OK-432 injection resulted in distant tumour suppression, prolonged survival, and increased dendritic cells, cytotoxic T cells, IFN-γ, and TNF-α, whereas RFA or OK-432 alone did not produce this effect. This combination may induce an abscopal effect in human osteosarcoma.

The number of patients with primary malignant bone and soft tissue tumors in Japan is increasing in line with the increasing size of the elderly population. The aim of the present study was to determine the prognostic factors of primary malignant bone or soft tissue tumors in elderly patients. Clinical data was obtained from 90 patients, aged ≥65 years, with primary malignant bone or soft tissue tumors (bone, 20 cases; and soft tissue, 70 cases), treated at the Osaka City University Hospital between 1993 and 2013. Clinical information prior to treatment and tumor type, location, size, depth, grade and American Society of Anesthesiologists‑Physical Status (ASA‑PS) score were evaluated in order to identify prognostic factors using the Cox proportional hazards regression model. In addition, 5‑year survival rates were evaluated using the Kaplan‑Meier method. The average follow‑up period was 44.8 months and the 5‑year overall survival rate was 77.5%. In the multivariate analysis, ASA‑PS score and high‑grade sarcoma were found to be associated with a poorer overall survival. No significant differences were observed between the patient group aged 65‑74 years and that aged ≥75 years. In general, aging is associated with physically reduced function and an increased prevalence of comorbidities. It was therefore expected that increasing age may be a predictive factor for poor prognosis. However, the results of the present study suggested that ASA‑PS score and tumor grade were significant factors associated with poor prognosis, whereas increasing age was not. Therefore, the treatment of elderly patients with primary bone and soft tissue tumors should not be based on age.

Many surgeons participate in the management of superficial soft tissue masses, and a preoperative incorrect diagnosis frequently results in dismal oncological outcomes. The aim of this study was to identify distinguishing magnetic resonance imaging features between malignant and non-malignant lesions. The clinicopathological data for 219 patients (men 114; women 105) with superficial soft tissue masses treated from January 2007 to December 2016 in our institution were retrospectively analyzed. The median age at the first visit was 55.6 years (range 1–90 years). MRI findings of tumor size, margin, lobulation, intratumoral hemorrhage, peritumoral edema, and tumor-fascia relationship were compared with the final histological diagnosis and tumor grade. Univariate analysis revealed significant relationships between histologically malignant lesions and tumor size ≥5 cm (p = 0.035), positive peritumoral edema (p = 0.031), and tumor-fascia relationship (p<0.001), but not margin (p = 0.107), lobulation (p = 0.071), and intratumoral hemorrhage (p = 0.17). In addition, using multivariate analysis, the tumor-fascia relationship (p<0.001) and tumor size were significant factors. A significant correlation between tumor-fascia relationship and malignancy (p<0.001) was observed; such a relationship was, however, not observed for tumor grade (p = 0.43). Tumors measuring ≥5 cm and the tumor-fascia relationship on magnetic resonance imaging are highly indicative of malignancy. When superficial soft tissue masses cross the superficial fascia and form obtuse angles with the fascia, sarcoma should be considered. The tumor-fascia relationship can offer surgeons useful information regarding the status of superficial soft tissue masses.

The aim of this study was to investigate the influence of systemic chemotherapy on the skeletal growth of young osteosarcoma patients as a treatment-related late adverse effect. We reviewed the height data of 20 osteosarcoma patients (13 males and 7 females) aged ≤18 years. The average (±SD) age at diagnosis was 14.5 (±3.3) years. The average follow-up interval was 89.6 months. After wide resection of the affected bones, reconstruction with tumor prostheses and auto-bone grafting was carried out in 11 and 9 cases, respectively. Pearson’s correlation coefficient was calculated to evaluate the association between actual and predicted (using Paley’s multiplier method) heights. Z-scores were used to compare the initial and final heights with the Japanese national growth curve. Actual and predicted heights were correlated according to Pearson’s correlation coefficient (R = 0.503). Z-analysis showed that statistical significance (p = 0.04) was noted for the height data Z-scores of patients between ≤10 years and >10 years at the final follow-up. Systemic chemotherapy did not reduce skeletal growth in young osteosarcoma patients as a late adverse effect based on two different evaluation methods. However, patients aged ≤10 years at diagnosis may develop a short stature after systemic chemotherapy.

Biopsy hole for bone tumour biopsy may cause pathological fractures. This study aimed to identify the optimal shape of bone tumour biopsy hole using the rabbit femoral head compression test to avoid pathological fracture. A compression test with no defect was performed to identify bone fracture location. Three shapes of biopsy holes (same size) were made artificially. Sixty rabbit femurs were randomly divided (n=15 each) into control (no defect), Shape 1 (round), Shape 2 (square), and Shape 3 (rectangular) groups. Twelve out of fifteen femurs were fractured on the femoral shaft; the femoral shaft was targeted for the compression test. Compressive maximum load and fracture energy were significantly higher for Shape 3 than for the other Shapes. A rectangular biopsy hole helps minimise reduction in bone strength. The defect width may be related to fragility of the affected bone.