Bone metastases cause morbidity and mortality in several human cancer forms. Experimental models are used to unravel the mechanisms and identify possible treatment targets. The location inside the skeleton complicates accurate assessment. This study evaluates the performance of magnetic resonance imaging (MRI) of prostate cancer tumors growing intratibially in mice. MRI detected intratibial tumor lesions with a sensitivity and specificity of 100% and 89%, respectively, compared to histological evaluation. Location and some phenotypical features could also be readily detected with MRI. Regarding volume estimation, the correlation between MRI and histological assessment was high (p < 0.001, r = 0.936). In conclusion, this study finds MRI to be a reliable tool for in vivo, non-invasive, non-ionizing, real-time monitoring of intratibial tumor growth.

OBJECTIVE: Lumbosacral vertebral osteoblastic metastasis is treated with percutaneous vertebroplasty (PVP) combined with 125I seed implantation and PVP alone. Compared to PVP alone, we evaluated the effects of combination therapy with PVP and 125I seed implantation on pain, physical condition, and survival and evaluated the clinical value of PVP combined with 125I particle implantation.
METHODS: We retrospectively analyzed 62 patients with lumbosacral vertebral osseous metastases treated at our hospital between 2016 and 2019. All the patients met the inclusion criteria for 125I implantation, and they were randomly divided into a combined treatment group and a pure PVP surgery group. The visual analog pain scale (VAS), Karnofsky Performance Status (KPS), and survival time were recorded at different time points, including preoperative, postoperative 1 day, 1 month, 3 months, 6 months, 12 months, and 36 months in each group. The variation in clinical indicators and differences between the groups were analyzed using SPSS version 20.0. Correlations between different variables were analyzed using the nonparametric Spearman\'s rank test. The Kaplan-Meier method was used to estimate the relationship between survival time and KPS score, VAS score, or primary tumor progression, and survival differences were analyzed using the log-rank test. Multivariate analyses were performed using a stepwise Cox proportional hazards model to identify independent prognostic factors.
RESULTS: Compared to the PVP treatment group, the pain level in the combined treatment group was significantly reduced (P = 0.000), and the patient\'s physical condition in the combination treatment group significantly improved. Kaplan-Meier analysis showed that the survival rate of the PVP group was significantly lower than that of the combination group (P = 0.038). We also found that the median survival of patients in both groups significantly increased with an increase in the KPS score (14 months vs. 33 months) (P = 0.020). Patients with more than three transfer sections had significantly lower survival rates than those with one or two segments of the section (P = 0.001). Further, Cox regression analysis showed that age (P = 0.002), the spinal segment for spinal metastasis (P = 0.000), and primary tumor growth rate (P = 0.005) were independent factors that affected the long-term survival of patients with lumbosacral vertebral osseous metastases.
CONCLUSIONS: PVP combined 125I seeds implantation surgery demonstrated superior effectiveness compared to PVP surgery alone in treating lumbosacral vertebral osseous metastases, which had feasibility in the clinical operation. Preoperative KPS score, spine transfer section, and primary tumor growth rate were closely related to the survival of patients with lumbosacral vertebral osteoblastic metastasis. Age, spinal segment for spinal metastasis, and primary tumor growth can serve as prognostic indicators and guide clinical treatment.

OBJECTIVE: To investigate measurements derived from plain and enhanced spectral CT in differentiating osteoblastic bone metastasis (OBM) from bone island (BI).
METHODS: From January to November 2020, 73 newly diagnosed cancer patients with 201 bone lesions (OBM = 92, BI = 109) having received spectral CT were retrospectively enrolled. Measurements including CT values of 40-140 keV, slope of the spectral curve, effective atomic number (Zeff), water (calcium) density, calcium (water) density, and Iodine (calcium) density were derived from manually segmented lesions on plain and enhanced spectral CT, and then analyzed using Student t-test and Pearson\'s correlation. Multivariate analysis was performed to build models (plain spectral model, enhanced spectral CT model, and combined model) for the discrimination of OBM and BI with performance evaluated using receiver operator characteristics curve and DeLong test.
RESULTS: All features were significantly different between the BI group and OBM group (all p < 0.05), highly correlated with the corresponding features between plain and enhanced spectral CT both in OBM (r: 0.392-0.763) and BI (r: 0.430-0.544). As for the model performance, the combined model achieved the best performance (AUC = 0.925, 95% CI: 0.879 to 0.957), which significantly outperformed the plain spectral CT model (AUC = 0.815, 95% CI: 0.754 to 0.866, p < 0.001) and enhanced spectral CT model (AUC = 0.901, 95% CI: 0.852 to 0.939, p = 0.024) in differentiating OBM and BI.
CONCLUSIONS: In addition to plain spectral CT measurements, enhanced spectral CT measurements would further significantly benefit the differential diagnosis.
CONCLUSIONS: Measurements derived either from plain or enhanced spectral CT could provide additional valuable information to improve the differential diagnosis between OBM and BI in newly diagnosed cancer patients.
CONCLUSIONS: • We intend to investigate plain and enhanced spectral CT measurements in differentiating OBM from BI. • Both plain and enhanced spectral CT help in discriminating OBM and BI in newly diagnosed cancer patients. • Enhanced spectral CT measurements further improve plain spectral CT measurements-based differential diagnosis.

Congenital/neonatal bone neoplasms are extremely rare. We present the case of a patient with a neonatal bone tumor of the fibula that had osteoblastic differentiation and a novel PTBP1::FOSB fusion. FOSB fusions are described in several different tumor types, including osteoid osteoma and osteoblastoma; however, these tumors typically present in the second or third decade of life, with case reports as young as 4 months of age. Our case expands the spectrum of congenital/neonatal bone lesions. The initial radiologic, histologic, and molecular findings supported the decision for close clinical follow-up rather than more aggressive intervention. Since the time of diagnosis, this tumor has undergone radiologic regression without treatment.

OBJECTIVE: To evaluate bone density changes at the level of normal trabecular bone and bone metastases (BMs) after denosumab (DM) treatment in oncologic patients.
METHODS: We retrospectively evaluated 31 consecutive adult patients with histologically confirmed solid tumors with at least one newly diagnosed bone metastatic lesion detected at CT. Patients received treatment with DM, 120 mg subcutaneous every 28 days for at least 6 months. Bone density was determined at the level of BMs and at the level of normal trabecular bone of lumbar vertebrae using a region of interest (ROI)-based approach.
RESULTS: A progressive increase in CT bone density was demonstrated at the level of normal trabecular bone at 6 months (18% ± 5%) and 12 months (23% ± 7%) after the treatment begins. BMs showed a significant increase in CT bone density (p < 0.05) as compared to baseline after 6 months (57% ± 15%) and 12 months (1.06 ± 0.25 times higher) after treatment.
CONCLUSIONS: We have found that long-term treatment with DM increases bone density progressively in oncologic patients. This effect can be observed not only at the level of secondary lesions but also at the level of apparently normal trabecular bone and is more pronounced for osteolytic metastases.

Limited tissue in biopsies of malignant bone lesions can preclude definitive subclassification, especially when cellular or matrix elements are sparse, absent, or confounding. It is uncertain whether immunohistochemistry for SOX9 (marker of chondrogenesis) and SATB2 (marker of osteoblastic differentiation) may be discriminatory tools toward osteosarcoma and chondrosarcoma. This study interrogated the preresection biopsies of a cohort of osteosarcoma and chondrosarcoma with SATB2 and SOX9 in tandem, to assess their value as diagnostic adjuncts as well as their concordance with the final resection diagnoses. SATB2 was expressed more frequently in osteosarcoma (46/53, 86%) than in chondrosarcoma (9/18, 50%); SOX9 was expressed in high frequencies in both osteosarcoma (52/53, 98%) and chondrosarcoma (17/18, 94%), and SATB2 and SOX9 were coexpressed in both osteosarcoma (46/53, 89%) and chondrosarcoma (8/18, 44%). There exists significant overlap in the expression of SATB2 and SOX9 in osteosarcoma and chondrosarcoma. These markers are not expressed in a distribution that is unique enough for application toward this particular diagnostic differential.

The aim of the study was to elaborate the incidence and type of skeletal involvement in a large cohort of patients with newly diagnosed prostate cancer (PCa) referred for Ga-68 PSMA-11 PET/CT staging in a single center.
Study cohort included 963 consecutive patients with newly diagnosed PCa referred for Ga-68 PSMA-11 PET/CT study for staging. The incidence of bone involvement, type of bone metastases, and extent of disease were determined and correlated with the ISUP Grade Group (GG) criteria and PSA levels.
Bone metastases were found in 188 (19.5%) of 963 patients. Bone metastases were found in 10.7% of patients with PSA < 10 ng/dL and in 27.4% of patients with PSA > 10 ng/dL and in 6.1% of patients with GG ≤ 2/3 and in 8.9% of patients with GG 4/5. In 7.6% of the patients, skeletal involvement was extensive, while 11.9% of patients had oligometastatic disease. Osteoblastic type metastases were the most common type of bone metastases presented in 133 of the patients with malignant bone involvement (70.7%). More than half of them had only osteoblastic lesions (72 patients (38.3%)), while the other (61 patients (32.5%)) had also intramedullary and/or osteolytic type lesions. Intramedullary metastases were found in 97 patients (51.6%), while 41 (21.8%) of them were only intramedullary lesions. Osteolytic metastases were detected in 36 patients (19.2%), of which 8 were only osteolytic lesions.
Although traditionally bone metastases of PCa are considered osteoblastic, osteolytic and intramedullary metastases are common, as identified on PET with labeled PSMA. Skeletal spread may be present also in patients with GG ≤ 2/3 and PSA < 10 ng/dL.

OBJECTIVE: To retrospectively evaluate the clinical efficacy and safety of percutaneous kyphoplasty (PKP) for the management of osteoblastic-related metastatic vertebral lesions.
METHODS: A total of 31 patients with 58 osteoblastic-related metastatic vertebral lesions underwent PKP were reviewed. The clinical efficacy was assessed based on parameters including visual analogue scale, Oswestry Disability Index, vertebral body height variation and quality of life. Major and minor complications were systematically evaluated to assess the safety of the procedure.
RESULTS: Average follow-up period was 22.5 ± 11.1 months(range, 3 to 46 months). The procedure duration time ranged from 50 to 180 minutes (average 96.8 ± 36.9 minutes). Mean visual analogue scale scores decreased significantly from 6.1 ± 1.8 pre-operatively to 2.7 ± 1.5 at 3 days after PKP (p < 0.001), and remained largely immutable at 1 month (2.0 ± 0.7; 31 patients; p < 0.001), 3 months (2.4 ± 1.2; 30 patients; p < 0.001) and 1 year (3.0 ± 1.0; 27 patients; p < 0.001). Oswestry Disability Index scores and vertebral body height variation also changed after the procedure, with significant differences between pre-operative scores and at each follow-up examination (p < 0.001). Mean quality of life scores were 90.8 ± 12.9 pre-operatively and improved to 99.5 ± 12.1(27 patients, p < 0.001) at 1 year after PKP. The only minor encountered complication was bone cement leakage, which was seen in 6.5%(2 of 31) of patients. None of the patients experienced major complications.
CONCLUSIONS: PKP is a safe and effective treatment strategy for osteoblastic-related metastatic vertebral lesions from a variety of tumor etiologies.

OBJECTIVE: To (a) develop a preconditioned water-fat total field inversion (wfTFI) algorithm that directly estimates the susceptibility map from complex multi-echo gradient echo data for water-fat regions and to (b) evaluate the performance of the proposed wfTFI quantitative susceptibility mapping (QSM) method in comparison with a local field inversion (LFI) method and a linear total field inversion (TFI) method in the spine.
METHODS: Numerical simulations and in vivo spine multi-echo gradient echo measurements were performed to compare wfTFI to an algorithm based on disjoint background field removal (BFR) and LFI and to a formerly proposed TFI algorithm. The data from 1 healthy volunteer and 10 patients with metastatic bone disease were included in the analysis. Clinical routine computed tomography (CT) images were used as a reference standard to distinguish osteoblastic from osteolytic changes. The ability of the QSM methods to distinguish osteoblastic from osteolytic changes was evaluated.
RESULTS: The proposed wfTFI method was able to decrease the normalized root mean square error compared to the LFI and TFI methods in the simulation. The in vivo wfTFI susceptibility maps showed reduced BFR artifacts, noise amplification, and streaking artifacts compared to the LFI and TFI maps. wfTFI provided a significantly higher diagnostic confidence in differentiating osteolytic and osteoblastic lesions in the spine compared to the LFI method (p = .012).
CONCLUSIONS: The proposed wfTFI method can minimize BFR artifacts, noise amplification, and streaking artifacts in water-fat regions and can thus better differentiate between osteoblastic and osteolytic changes in patients with metastatic disease compared to LFI and the original TFI method.

Osteosarcoma (OS) accounts for about 20% of all sarcomas with gnathic involvement seen in about 6%-10% of all OSs. The clinical presentation of OSs in the jaws is different from that of long bones as swelling is the most common complaint in patients with jaw OS followed by pain. The histopathologic variables seen are more favorable in OSs of jaws. Low-grade tumors are Stage I, high-grade tumors are Stage II and metastatic tumors (regardless of grade) are Stage III. A 17-year-old male patient reported with a complaint of the presence of an intra-oral growth gradually increasing in size in the right buccal mucosa region soft tissue enveloping the occlusal aspect of the right mandibular second molar. Extraorally swelling was present on the right side of the face for 4 months. Radiographically, there was a radiolucency from the distal aspect of right Mandibular second molar extending into the ramus region of the mandible with ill-defined borders. Hemi-mandibulectomy was done with the removal of the right mandible from the premolar region to condyle and coronoid processes. Microscopic evaluation of the sections after hematoxylin and eosin staining revealed interlacing fascicles of spindle-shaped cells arranged in a biphasic pattern and some areas of attempted bone formation evident in deeper sections. Tumor was an osteoblastic variety consisting of tumor osteoid surrounded by bizarrely arranged fibroblast-like cells. It showed positive staining with α-smooth muscle actin and Vimentin, suggesting a malignant tumor of mesenchymal cells with high myofibroblastic activity. Our case had small-cell histology; therefore, differential diagnosis was important.