Challenges in the Diagnosis of bone Metastasis in Patients without a History of Malignancy at Their First Clinic Visit

New Image Processing Method for Plain Radiography Improves Detection of Bone Metastases

BACKGROUND

Diagnosis of bone metastases would be hastened if they could be detected on plain radiographs obtained at the first visit to an orthopedic surgeon. However, lesions are often undetectable on plain radiography. Bone metastasis is diagnosed at the first visit in only a few patients, and diagnosis is delayed in many cases. We investigated the diagnostic performance of plain radiography that used a new image processing method, Dynamic Visualization II (DV), to diagnose bone metastases.

METHODS

We enrolled 29 patients with symptomatic pelvic bone metastases who visited our hospital between April 2018 and March 2021. The evaluation images were created by processing the original plain radiography data with the default settings for DV (Presets 1-4). Processing with Preset 1 resulted in an image converted to conventional film parameters, whereas Presets 2-4 utilized different DV processing methods. The readers were six orthopedic trainees, and the reading time was 30 seconds per image. The rate of correct answers for images processed with Preset 1 was compared to the rates for those processed with the other presets. Additionally, the rate of correct answers was analyzed in relation to clinical variables.

RESULTS

The correct answer rate was significantly higher for Preset 3 (43.7%) and Preset 4 (42.5%) than for Preset 1 (28.7%). Correct answer rates for Presets 3 and 4 were significantly higher for elderly patients, male patients, patients with innominate bone lesions, patients with osteolytic bone metastases, and patients with a normal body weight.

CONCLUSIONS

Image processing by DV improved diagnosis of bone metastases by plain radiography. DV might hasten diagnosis of bone metastases and help prevent associated complications.

Dual-Energy Computed Tomography For Differentiation Between Osteoblastic Metastases and Bone Islands

Objective

The objective of our study was to evaluate the utility of Rho/Z on dual-energy computed tomography (DECT) for the differentiation of osteoblastic metastases (OBMs) from bone islands (BIs).

Methods

DECT images of 110 patients with malignancies were collected. The effective atomic number (Z), electron density (Rho), dual energy index (DEI), and regular CT (rCT) values were measured by two observers. Independent-sample t-test was used to compare these values between OBMs and BIs. The diagnostic performance was assessed by receiver operating characteristic (ROC) analysis and the cutoff values were evaluated according to ROC curves.

Results

A total of 205 OBMs and 120 BIs were included. The mean values of Z, Rho, DEI, and rCT of OBMs were significantly lower than those of BIs, whereas the standard deviation values were higher than those of BIs (all p ≤ 0.05). ROC analysis showed that 11.86 was the optimal cutoff value for Z, rendering an area under the ROC curve (AUC) of 0.91, with a sensitivity of 91.2% and a specificity of 82.5%.

Conclusion

DECT can provide quantitative values of Z, Rho, and DEI and has good performance in differentiating between OBMs and BIs.

Effective examination methods for identifying the primary origins of metastatic bone tumors of unknown primary origin during the initial visit: A retrospective chart review study

Objective:

To provide appropriate treatment for patients, early diagnosis of the primary origin of skeletal metastases of unknown primary origin is important. This study aimed to assess the examination strategy effective for identifying the primary origin of skeletal metastases of unknown primary origin.

Methods:

Sixty-one patients with skeletal metastases of unknown primary origin were reviewed. The primary origin was examined via physical examination, blood test including tumor markers, chest radiography, thoracoabdominal computed tomography scan, positron emission tomography–computed tomography scan, metastatic lesion biopsy, and other assessments. Examination methods considered effective for the diagnosis of the primary origin in a specific type of cancer were investigated.

Results:

The lung was the most common primary origin site, followed by the lymph nodes, prostate, and breast. Meanwhile, biopsy was the most effective examination, followed by positron emission tomography–computed tomography scan and thoracoabdominal computed tomography scan. Blood tests are useful for detecting hematological malignancies and prostate cancer. Computed tomography scans can be used to identify cancers in the lung, breast, and kidney, which are the common primary origins. Forty-one (67.2%) of the 61 patients with skeletal metastases of unknown primary origin were diagnosed via the first four steps, that is, physical examination, blood test, chest radiography, and thoracoabdominal computed tomography scan. Finally, two patients were diagnosed with skeletal metastases of unknown primary origin.

Conclusion:

The examination steps used in this study, including physical examination, blood test including tumor markers, chest radiography, thoracoabdominal computed tomography scan, positron emission tomography–computed tomography scan, biopsy, and other assessments were effective in determining the primary origin of skeletal metastases of unknown primary origin during the initial visit.

Biomaterials for Orthopaedic Diagnostics and Theranostics

Despite widespread use of conventional diagnostic methods in orthopaedic applications, limitations still exist in detection and diagnosing many pathologies especially at early stages when intervention is most critical. The use of biomaterials to develop diagnostics and theranostics, including nanoparticles and scaffolds for systemic or local applications, has significant promise to address these shortcomings and enable successful clinical translation. These developments in both modular and holistic design of diagnostic and theranostic biomaterials may improve patient treatments for myriad orthopaedic applications ranging from cancer to fractures to infection.

Association of Pedicle Sign Type with Clinical and Radiological Features in Patients with Symptomatic Spinal Metastases

BACKGROUND

Because of population aging in Japan, the number of cancer diagnoses is increasing rapidly. The pedicle sign is a valuable radiographic indicator of metastases, as the pedicle is the most commonly affected vertebral structure in radiographic assessment. However, few studies have carefully examined the morphological features of pedicle signs. To improve the capacity of medical professionals to diagnose symptomatic spinal metastases, we retrospectively examined the morphological characteristics of pedicle signs and their associations with clinical and radiological features.

METHODS

186 patients with symptomatic spinal metastases who visited our department during the period from January 1, 2011 through December 31, 2017 were enrolled. The pedicle sign was defined as a missing or obscured pedicle on an anteroposterior radiograph. Radiographs were evaluated for pedicles and other vertebrae structures. Clinical and other radiological features were compared in relation to the type of pedicle sign identified.

RESULTS

Pedicle signs were classified as completely disappeared (complete, 26 patients), partially disappeared (partial, 40 patients), or obscured by the osteoblastic background (blastic, 28 patients). Disappearance of both the bone cortex and pedicle was observed in almost half of the patients with complete or partial pedicle signs. The complete pedicle sign was associated with significantly longer survival.

CONCLUSION

Diagnosis of bone metastases requires understanding of pedicle sign types.

Development and Verification of Educational Material for Plain Radiographic Diagnosis of Bone Metastasis: A Preliminary Report

Our previous studies showed that early diagnosis of painful bone metastasis is difficult and requires improvement in the diagnostic accuracy of plain radiography during an initial patient consultation. In this preliminary study, we evaluate the usefulness of educational material used to improve diagnosis of bone metastasis with plain radiography. This study included imaging data from 129 consecutive patients who visited our orthopedic clinic during the period January 2011 through December 2014. First, we prepared a test to measure the reading ability of orthopedic practitioners, after which the educational material was created. Then, the effectiveness of the educational material was verified by having orthopedic trainees take a pre-test and post-test. The test contained plain radiographic data from 12 patients with lesions and 6 without lesions. The educational material included plain radiographic data from 30 patients with typical findings of bone metastasis, as well as diagnostic magnetic resonance images or computed tomography scans, accompanied by a lecture. The accuracy and sensitivity of diagnosis significantly improved after the lecture; however, specificity decreased. Although the educational material was effective for improving the ability of orthopedic trainees to read plain radiographs of bone metastasis, some aspects of the program need to be improved and revised.

Symptoms Related to Moderate Skeletal-Related Events as Clues for the Diagnosis of Bone Metastasis

BACKGROUND

Early diagnosis of bone metastasis is difficult. The aim of the present study was to determine whether symptoms related to skeletal-related events (SREs) can be used for the diagnosis of bone metastasis in the absence of screening tests.

METHODS

We reviewed 81 patients with bone metastasis to evaluate their SREs at diagnosis. SREs were arbitrarily classified as moderate or severe. Moderate SREs included radiation to the bone before pathological fracture or paralysis, bone surgery before pathological fracture or paralysis, and hypercalcemia without dialysis. Severe SREs included pathological fracture, spinal cord compression, and hypercalcemia necessitating dialysis.

RESULTS

The complication rates of SREs at the time the bone metastasis was diagnosed were 59.3% and 24.7% for severe and moderate SREs, respectively, and only 16.0% of cases were uncomplicated. The clinical factors that showed a significant relationship with the severity of SREs were age and history of malignancy. However, there was no significant relationship between the complication rate of total SREs and the presence or absence of a malignancy history (83.3% vs. 85.2%, respectively, p=0.83).

CONCLUSION

The results of the present study suggest that symptoms related to SREs can be used to diagnose bone metastasis in the absence of a screening test. Bone metastasis should be diagnosed as often as possible based on symptoms related to moderate SREs and should be treated as soon as possible before patients develop severe SREs.