Diagnostic accuracy of imaging methods for the diagnosis of skeletal malignancies: A retrospective analysis against a pathology-proven reference

Expert Panel on Musculoskeletal Imaging, Ahlawat S, Lenchik L, Baker JC, Allen H, Banks J, Florou V, Garner HW, Hammer MR, Hiniker SM, Kamel SI, Lu Y, Peairs KS, Scott JA, Wessell DE. ACR Appropriateness Criteria® Suspected Primary Bone Tumors: 2024 Update

Despite the rarity of primary bone tumors, appropriate imaging evaluation is essential for diagnosis and management. Radiographs are the most appropriate initial imaging study for detection and characterization of the majority of primary bone tumors. Radiographs often provide sufficient information for the diagnosis of primary bone tumors, however, for radiographically occult primary bone tumors, MRI and/or CT can be performed. For indeterminate or aggressive bone tumors on radiographs, MRI or CT are typically the most appropriate next step for the evaluation of anatomic extent, assessment of viability and biopsy or surgical planning. This document focuses on five common variants to guide diagnosis and management of primary bone tumors. In addition to conventional radiographs, appropriate use of MRI, CT, PET/CT, bone scan, image-guided biopsy and ultrasound are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Diagnostic accuracy of imaging modalities for detection of spinal metastases: a systematic review and meta-analysis

PURPOSE

Detecting spinal metastases is highly relevant in patients with oncological disorders as it can affect the staging and treatment of their disease. We aimed to evaluate the diagnostic performance of computed tomography (CT), magnetic resonance imaging (MRI), FDG positron emission tomography (PET)/CT, bone scintigraphy (BS), and single-photon emission computed tomography (SPECT) for spinal metastases detection.

METHODS

Medline, EMBASE, and Web of Science were systematically searched until March 2024 for diagnostic accuracy studies on spinal metastases detection (PROSPERO-registration: CRD42024540139). Data extraction and quality assessment using the QUADAS-2 tool were performed by two independent reviewers. Using bivariate random effects modeling, pooled sensitivities, specificities, and diagnostic odds ratios (DOR) were calculated, and hierarchical summary operating curves were constructed.

RESULTS

Twenty-five studies (49 datasets), encompassing 3102 patients were included. Per-patient pooled sensitivities of CT, MRI, PET/CT, BS and SPECT were 70%, 93%, 82%, 75%, and 84%, respectively. Pooled specificities were 74%, 85%, 75%, 92%, and 81%, respectively. Per-lesion pooled sensitivities of CT, MRI, PET/CT, BS and SPECT were 76%, 91%, 92%, 77%, and 92%, respectively. Pooled specificities were 91%, 94%, 85%, 52%, and 86%, respectively. MRI had the highest DOR in per patient and lesion analyses.

CONCLUSION

MRI had highest diagnostic accuracy for spinal metastases detection on patient and lesion level, suggesting a broader use in addition to the routine staging CT, at least in patients at high risk and where the detection of a spinal metastasis could alter therapy decisions. Herein, results should be considered with the limitations of each modality.

Shoulder girdle neoplasm misdiagnosis and clinical manifestations: A scoping review

Introduction

The aim of this review is to outline the clinical presentation of patients with shoulder girdle neoplasm to help differentiate it from frozen shoulder contracture syndrome (FSCS) as well as quantify misdiagnosis rates in the literature.

Methods

Four electronic databases were searched (Embase, Medline, PUBMED and Scopus) for cohort studies of patients with shoulder girdle neoplasm with or without misdiagnosis as FSCS in line with the PRISMA-ScR guidelines for scoping reviews.

Results

The initial search yielded 2462 studies, 10 of which were included in the final review. The most common symptom of patients with shoulder girdle neoplasm was shoulder pain (62%) followed by swelling/mass/deformity (34%) and local/bony tenderness (13%). In patients with neoplasm initially misdiagnosed as FSCS the main complaints were shoulder pain and subjective stiffness/loss of range of motion (73% each). Misdiagnosis rates ranged from 10% to 50% and resulted in diagnostic delays of up to 30 months.

Conclusions

Key clinical features of bone and soft tissue tumours such as local bony tenderness and careful observation for swelling/mass/deformity should be included in the physical examination to help differentiate between the two pathologies and help guide the choice of initial imaging for the primary contact clinician.

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.

Prostate-Specific Membrane Antigen PET/Computed Tomography: Pearls and Pitfalls

Prostate-specific membrane antigen PET (PSMA-PET) has emerged as a powerful imaging tool for prostate cancer primary staging, biochemical recurrence, and advanced disease assessment. This article offers a concise overview of the benefits and challenges associated with PSMA-PET for prostate cancer evaluation. The article highlights the advantages of PSMA-PET over conventional imaging, such as its higher sensitivity and specificity for detecting metastases, and the potential for guiding personalized treatment decisions. However, it also explores the limitations and potential pitfalls for interpretation. Overall, the article aims to provide valuable insights for clinicians and diagnostic imaging physicians in clinical practice.

Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.

Deep learning-based magnetic resonance imaging of the spine in the diagnosis and physiological evaluation of spinal metastases

Background and objective

Spinal metastasis accounts for 70% of the bone metastases of tumors, so how to diagnose and predict spinal metastasis in time through effective methods is very important for the physiological evaluation of the therapy of patients.

Methods

MRI scans of 941 patients with spinal metastases from the affiliated hospital of Guilin Medical University were collected, analyzed, and preprocessed, and the data were submitted to a deep learning model designed with our convolutional neural network. We also used the Softmax classifier to classify the results and compared them with the actual data to judge the accuracy of our model.

Results

Our research showed that the practical model method could effectively predict spinal metastases. The accuracy was up to 96.45%, which could be used to diagnose the physiological evaluation of spinal metastases.

Conclusion

The model obtained in the final experiment can capture the focal signs of patients with spinal metastases more accurately and can predict the disease in time, which has a good application prospect.

X-ray and MRI Correlation of Bone Tumors Using Histopathology As Gold Standard

Introduction

Bone tumors are a common pathology of the musculoskeletal system being frequently encountered by clinicians. Radiological workup is a mainstay in the diagnostic workup of bone tumors. This study aimed to highlight the importance of plain radiography and MRI in the diagnosis of bone tumors keeping histopathology as a gold standard. It is a descriptive validation study conducted in the Radiology Department of Pakistan Institute of Medical Sciences Islamabad.

Methodology

The study included 92 patients with suspected bone lesions. After taking a complete history and receiving informed written consent. X-rays radiographs and magnetic resonance imaging were performed. X-ray radiograph and magnetic resonance imaging parameters were recorded and compared with the histopathology of lesions as a standard.

Results

The mean age of patients was 30.50 ± 8.95 years. Of 92 patients examined on X-ray, 51 (55.4%) had lytic lesions, 34 (37.0%) had sclerotic lesions, and seven (7.6 %) had mixed lesions. MRI revealed the location of the lesion. There were 25 (27.2%) bone lesions in diaphysis, 19 (20.7%) in metaphysis, nine (9.8%) at meta-diaphysis, and 32 (34.8 %) in the meta-epiphyseal region. These findings were later on confirmed with histopathological results.

Conclusion

MRI can differentiate soft-tissue components and periosteal reactions. An X-ray radiograph can provide information about bony matrix and calcifications within tumors. After analysis of imaging findings and histopathological results, it is concluded that these modalities can be used to diagnose bone tumors with high diagnostic accuracy.

Influence of Prior Imaging Information on Diagnostic Accuracy for Focal Skeletal Processes—A Retrospective Analysis of the Consistency between Biopsy-Verified Imaging Diagnoses

Introduction: Comparing imaging examinations with those previously obtained is considered mandatory in imaging guidelines. To our knowledge, no studies are available on neither the influence, nor the sequence, of prior imaging and reports on diagnostic accuracy using biopsy as the reference standard. Such data are important to minimize diagnostic errors and to improve the preparation of diagnostic imaging guidelines. The aim of our study was to provide such data. Materials and methods: A retrospective cohort of 216 consecutive skeletal biopsies from patients with at least 2 different imaging modalities (X-ray, CT and MRI) performed within 6 months of biopsy was identified. The diagnostic accuracy of the individual imaging modality was assessed. Finally, the possible influence of the sequence of imaging modalities was investigated. Results: No significant difference in the accuracy of the imaging modalities was shown, being preceded by another imaging modality or not. However, the sequence analyses indicate sequential biases, particularly if MRI was the first imaging modality. Conclusion: The sequence of the imaging modalities seems to influence the diagnostic accuracy against a pathology reference standard. Further studies are needed to establish evidence-based guidelines for the strategy of using previous imaging and reports to improve diagnostic accuracy.

ESTRO ACROP guidelines for external beam radiotherapy of patients with uncomplicated bone metastases

After liver and lungs, bone is the third most common metastatic site (Nystrom et al., 1977). Almost all malignancies can metastasize to the skeleton but 80% of bone metastases originate from breast, prostate, lung, kidney and thyroid cancer (Mundy, 2002). Introduction of effective systemic treatment in many cancers has prolonged patients' survival, including those with bone metastases. Bone metastases may significantly reduce quality of life due to related symptoms and possible complications, such as pain and neurologic compromise. The most serious complications of bone metastases are skeletal-related events (SRE), defined as pathologic fracture, spinal cord compression, pain, or other symptoms requiring an urgent intervention such as surgery or radiotherapy. In turn, growing access to modern diagnostic tools allows early detection of asymptomatic bone metastases that could be successfully managed with local treatment avoiding development of SRE. The treatment for bone metastases should focus on relieving existing symptoms and preventing new ones. Radiotherapy is the standard of care for patients with symptomatic bone metastases, providing durable pain relief with minimal toxicity and reasonable cost-effectiveness. Historically, the dose was prescribed in one to five fractions and delivered using simple planning techniques. While 3D-conformal radiotherapy is still widely used for treating bone metastases, introduction of highlyconformal radiotherapy techniques such as stereotactic body radiotherapy (SBRT) have opened new therapeutic possibilities that should be considered in selected patients with bone metastases.

Validity of negative bone biopsy in suspicious bone lesions

Background

The presence of malignant cells in bone biopsies is considered gold standard to verify occurrence of cancer, whereas a negative bone biopsy can represent a false negative, with a risk of increasing patient morbidity and mortality and creating misleading conclusions in cancer research. However, a paucity of literature documents the validity of negative bone biopsy as an exclusion criterion for the presence of skeletal malignancies.

Purpose

To investigate the validity of a negative bone biopsy in bone lesions suspicious of malignancy.

Material and Method

A retrospective cohort of 215 consecutive targeted non-malignant skeletal biopsies from 207 patients (43% women, 57% men, median age 64, and range 94) representing suspicious focal bone lesions, collected from January 1, 2011, to July 31, 2013, was followed over a 2-year period to examine any additional biopsy, imaging, and clinical follow-up information to categorize the original biopsy as truly benign, malignant, or equivocal. Standard deviations and 95% confidence intervals were calculated.

Results

210 of 215 biopsies (98%; 95% CI 0.94-0.99) showed to be truly benign 2 years after initial biopsy. Two biopsies were false negatives (1%; 95% CI 0.001-0.03), and three were equivocal (lack of imaging description).

Conclusion

Our study documents negative bone biopsy as a valid criterion for the absence of bone metastasis. Since only 28% had a confirmed diagnosis of prior cancer and not all patients received adequately sensitive imaging, our results might not be applicable to all cancer patients with suspicious bone lesions.

Preconditioned water-fat total field inversion: Application to spine quantitative susceptibility mapping

PURPOSE

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).

CONCLUSION

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.

An international expert opinion statement on the utility of PET/MR for imaging of skeletal metastases

BACKGROUND

MR is an important imaging modality for evaluating musculoskeletal malignancies owing to its high soft tissue contrast and its ability to acquire multiparametric information. PET provides quantitative molecular and physiologic information and is a critical tool in the diagnosis and staging of several malignancies. PET/MR, which can take advantage of its constituent modalities, is uniquely suited for evaluating skeletal metastases. We reviewed the current evidence of PET/MR in assessing for skeletal metastases and provided recommendations for its use.

METHODS

We searched for the peer reviewed literature related to the usage of PET/MR in the settings of osseous metastases. In addition, expert opinions, practices, and protocols of major research institutions performing research on PET/MR of skeletal metastases were considered.

RESULTS

Peer-reviewed published literature was included. Nuclear medicine and radiology experts, including those from 13 major PET/MR centers, shared the gained expertise on PET/MR use for evaluating skeletal metastases and contributed to a consensus expert opinion statement. [18F]-FDG and non [18F]-FDG PET/MR may provide key advantages over PET/CT in the evaluation for osseous metastases in several primary malignancies.

CONCLUSION

PET/MR should be considered for staging of malignancies where there is a high likelihood of osseous metastatic disease based on the characteristics of the primary malignancy, hight clinical suspicious and in case, where the presence of osseous metastases will have an impact on patient management. Appropriate choice of tumor-specific radiopharmaceuticals, as well as stringent adherence to PET and MR protocols, should be employed.

A Retrospective Study of predicting risk of Metastasis among FDG-avid Bone Lesions in 18F-FDG PET/CT

Purpose: We evaluated the imaging and clinical features for discriminating the possibility of metastasis among FDG-avid bone lesions in 18F-FDG PET/CT in patients who have received bone biopsy.

Methods: The retrospective study included patients who underwent both ¹⁸F-FDG PET/CT and bone biopsy for FDG-avid bone lesions. Bone lesions maximum standardized uptake value (SUVmax), CT findings, alongside with common clinical features were analyzed.

Results: From the 338 patients enrolled in the final study, all of them were received bone biopsy. Biopsies confirm metastasis in 256 cases (75.74%) and benign tissue in 82 cases (24.26%). Metastasis group had higher bone SUVmax than benign group (median 7.9 vs 4.5, p <0.001). A cutoff bone SUVmax of 5 achieved an AUC of 0.748 in all patients. Lytic CT feature and higher age were more likely frequent in metastasis group. Moreover, in patients without obvious CT abnormality (45, 13.31%), the AUC was 0.743 by a SUVmax cutoff of 5.38, whilst in patients with a solitary bone lesion (74, 21.89%), the AUC was 0.803 by a SUVmax cutoff of 4.3.

Conclusions: SUVmax is a promising and valuable metabolic indicator for predicting risk of metastasis among FDG-avid bone lesions in 18F-FDG PET/CT, ancillary clinical and imaging features may increase the probability of a metastatic bone lesion.

ACR Appropriateness Criteria® Primary Bone Tumors

Although primary bone tumors are relatively uncommon, appropriate imaging evaluation is essential when they are suspected or incidentally detected. In almost all cases, radiographs are the most appropriate initial imaging study for screening and characterization of primary bone tumors. Radiographs often provide sufficient information for diagnosis and to guide the treating clinician. However, when conventional radiographs alone are inadequate, they still often guide the selection of the most appropriate next step for advanced imaging. MRI and CT are typically the most appropriate next step. MRI provides excellent soft-tissue contrast allowing for evaluation of the tissue composition (such as fat, hemorrhage, fluid levels) and anatomic extent of bone tumors. CT provides complementary information, with its ability to detect subtle matrix mineralization or periosteal reaction that may not be seen on radiographs or MRI. This publication focuses on six common variants to guide diagnosis and management of primary bone tumors. In addition to conventional radiographs, appropriate use of MRI, CT, PET/CT, bone scan, and ultrasound are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Established Nuclear Medicine Modalities for Imaging of Bone Metastases

Background:

The skeleton is one of the frequent site of metastases in advanced cancer. Prostate, breast and renal cancers mostly metastasize to bone.

Discussion:

Malignant tumors lead to significant morbidity and mortality. Identification of bone lesions is a crucial step in diagnosis of disease at early stage, monitoring of disease progression and evaluation of therapy. Diagnosis of cancer metastases is based on uptake of bone-targeted radioactive tracer at different bone remodeling sites.

Conclusion:

This manuscript summarizes already established and evolving nuclear medicine modalities (e.g. bone scan, SPECT, SPECT/CT, PET, PET/CT) for imaging of bone metastases.

Clinical-radiomics nomograms for pre-operative differentiation of sacral chordoma and sacral giant cell tumor based on 3D computed tomography and multiparametric magnetic resonance imaging

OBJECTIVE

To develop and validate clinical-radiomics nomograms based on three-dimensional CT and multiparametric MRI (mpMRI) for pre-operative differentiation of sacral chordoma (SC) and sacral giant cell tumor (SGCT).

METHODS

A total of 83 SC and 54 SGCT patients diagnosed through surgical pathology were retrospectively analyzed. We built six models based on CT, CT enhancement (CTE), T₁ weighted, T₂ weighted, diffusion-weighted imaging (DWI), and contrast-enhanced T₁ weighted features, two radiomics nomograms and two clinical-radiomics nomograms combined radiomics mixed features with clinical data. The area under the receiver operating characteristic curve (AUC) and accuracy (ACC) analysis were used to assess the performance of the models.

RESULTS

SC and SGCT presented significant differences in terms of age, sex, and tumor location (t_age = 9.00, χ²_sex = 10.86, χ²_location = 26.20; p < 0.01). For individual scan, the radiomics model based on diffusion-weighted imaging features yielded the highest AUC of 0.889 and ACC of 0.885, followed by CT (AUC = 0.857; ACC = 0.846) and CT enhancement (AUC = 0.833; ACC = 0.769). For the combined features, the radiomics model based on mixed CT features exhibited a better AUC of 0.942 and ACC of 0.880, whereas mixed MRI features achieved a lower performance than the individual scan. The clinical-radiomics nomogram based on combined CT features achieved the highest AUC of 0.948 and ACC of 0.920.

CONCLUSIONS

The radiomics model based on CT and multiparametricMRI present a certain predictive value in distinguishing SC and SGCT, which can be used for auxiliary diagnosis before operation. The clinical-radiomics nomograms performed better than radiomics nomograms.

ADVANCES IN KNOWLEDGE

Clinical-radiomics nomograms based on CT and mpMRI features can be used for preoperative differentiation of SC and SGCT.

Incidence of surgical interventions for metastatic bone disease in the extremities: a population-based cohort study

BACKGROUND

The incidence of surgery due to metastatic bone disease in the extremities (MBDex) and postoperative survival remain uninvestigated in the population. The aim of the current study was: to identify (1) incidence, demographics and survival of a population-based cohort of patients having surgery for MBDex (2) rate of referrals and referral pattern to a musculoskeletal tumour centre (MTC).

MATERIAL AND METHOD

A prospective study of a consecutive population-based cohort of patients having surgery for MBDex from 2014 to 2016. Patient demographics, indication for surgery, oncological status, and postoperative survival was obtained from patient interviews, surveillance scans and patient records.

RESULTS

We identified 164 patients treated for 175 bone lesions resulting in an incidence of MBDex surgery of 48.6 lesions/million inhabitants/year and a 10% risk of undergoing surgery for MBDex for every year liven with metastatic bone disease. The most common primary cancers were breast, lung, renal, prostate and myeloma. Twenty-nine lesions represented debut of cancer and 22 lesions debut of relapse of a previous cancer. Overall one-year survival was 41% (95% C.I.: 33%-48%). Fifty-nine percent of patients were referred for treatment at MTC. Patients referred had better prognostic baseline characteristic than patients treated at secondary surgical centres (SSC) (lower ASA score (p < .001), no visceral metastasis (p < .001), lower age (p < .001) and less aggressive primary cancer (p < .001)). The one-year probability of overall survival was higher for MTC patients compared to SSC patients (p < .001).

CONCLUSIONS

Present study describes a prospective population-based cohort of patients having surgery for MBDex identifying incidence and postoperative survival. Referral of patient is biased by selection where 'long-term survivors' are referred for treatment at MTC. We can, however, not exclude that treatment centre influences chance of survival after surgery for MBDex although our study was not designed to identify any potential influence.

Surveillance for Differentiated Thyroid Cancer Recurrence

Serum thyroglobulin monitoring along with anatomic and functional imaging play key roles in the surveillance of patients with differentiated thyroid cancer after initial treatment. Among patients with a disease stage justifying thyroid remnant ablation or with suspected metastatic disease, radioiodine whole-body scans are essential in the months after surgery. For patients with low to moderate-risk cancers, ultrasonography of the neck (with measurement of serum thyroglobulin on thyroid hormone replacement) are the best initial diagnostic modalities, and are often the only tests required. In individuals suspected of having distant metastases, CT, MRI, and 18F-FDG PET can make important contributions in localizing residual disease and monitoring its progression and responses to therapy, provided they are used in the appropriate setting.

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

BACKGROUND

Many patients with bone metastases whose diagnoses came only after they had suffered aggravated conditions are still frequently encountered. However, there have been few studies regarding the early diagnosis of such metastases. We retrospectively reviewed the clinical courses of cases we experienced between 2004 and 2014 to clarify the practical situation of diagnosis of such bone metastases.

METHODS

We undertook a retrospective review of 56 of our patients with bone metastasis who had no history of malignancy at their first visit, who visited our departments between 2004 and 2014. The initial diagnoses at the first visit to any clinic, the period from the first visit to any clinic to diagnosis of bone metastasis, the process to make the diagnosis, the frequency of severe skeletal-related events at diagnosis, and the examination serving as the basis for diagnosis were evaluated.

RESULTS

The diagnosis of bone metastasis was made at the first visit in only 6 of the 56 patients. Pathological fractures, paralysis and/or calcemia were seen in 62.5% of the patients at diagnosis of bone metastasis. The median period from the first visit to any clinic to diagnosis was 7.0 weeks. Typically, the diagnosis of bone metastasis was made only after aggravation. The most frequent examination to serve as the basis of diagnosis was magnetic resonance imaging.

CONCLUSIONS

Diagnosis of bone metastasis is challenging in patients without a history of malignancy at their first visit. For early diagnosis, it is important to recognize this challenge and to keep it in mind together with ongoing observation.

Diagnostic Value of Plain Radiography for Symptomatic Bone Metastasis at the First Visit

BACKGROUND

To prevent and minimize skeletal-related diseases, early diagnosis of bone metastases is important. However, previous reports have shown that plain radiography has low sensitivity and fails to screen multiple asymptomatic lesions. Limited investigations have been reported on the value of plain radiography in the diagnosis of symptomatic bone metastases. Therefore, this study aimed to investigate the diagnostic utility of plain radiography for symptomatic bone metastasis.

METHODS

Two experienced orthopedic surgeons retrospectively evaluated the plain radiographs of 39 patients with symptoms during their first visit between 2011 and 2014 for bone metastases. Another 2 experienced orthopedic surgeons then reviewed the data using 2 reference standards, the clinical results and the retrospectively evaluated results, in a blinded manner. The data were then reviewed by 2 certified orthopedic surgeons and 7 orthopedic surgeons in training with differing years of experience in a blinded manner.

RESULTS

The overall sensitivity of diagnosis of symptomatic bone metastasis using plain radiography at the clinic first visit was 71.4%. Upon blinded evaluation, the accuracy, sensitivity, and specificity were 55.8%, 54.3%, and 68.8% and 77.6%, 73.0%, and 85.7% for clinical results and results from 2 experienced orthopedic surgeons as a reference standard, retrospectively. There was a strong and significant correlation between the accuracy and observers' years of experience in orthopedic surgery among the orthopedic surgeons in training (R=0.942, p=0.0015).

CONCLUSIONS

Plain radiography around the time of the first visit has a definitive role in the early diagnosis of symptomatic bone metastasis.

Current evidence for spinal X-ray use in the chiropractic profession: a narrative review

The use of routine spinal X-rays within chiropractic has a contentious history. Elements of the profession advocate for the need for routine spinal X-rays to improve patient management, whereas other chiropractors advocate using spinal X-rays only when endorsed by current imaging guidelines. This review aims to summarise the current evidence for the use of spinal X-ray in chiropractic practice, with consideration of the related risks and benefits. Current evidence supports the use of spinal X-rays only in the diagnosis of trauma and spondyloarthropathy, and in the assessment of progressive spinal structural deformities such as adolescent idiopathic scoliosis. MRI is indicated to diagnose serious pathology such as cancer or infection, and to assess the need for surgical management in radiculopathy and spinal stenosis. Strong evidence demonstrates risks of imaging such as excessive radiation exposure, overdiagnosis, subsequent low-value investigation and treatment procedures, and increased costs. In most cases the potential benefits from routine imaging, including spinal X-rays, do not outweigh the potential harms. The use of spinal X-rays should not be routinely performed in chiropractic practice, and should be guided by clinical guidelines and clinician judgement.

Differentiation of Predominantly Osteoblastic and Osteolytic Spine Metastases by Using Susceptibility-weighted MRI

Purpose To evaluate the use of susceptibility-weighted MRI for the differentiation of predominantly osteoblastic and osteolytic spine metastases. Materials and Methods For this prospective study, 53 study participants (mean age, 54.5 years ± 14.3 [range, 22-88 years]; 27 men with a mean age of 55.3 years ± 12.7 [range, 22-72 years] and 26 women with a mean age of 53.8 years ± 15.7 [range, 23-88 years]) with clinically suspected spine metastases underwent imaging with standard MRI sequences, susceptibility-weighted MRI, and CT. Sensitivities and specificities of MRI sequences for the detection of predominantly osteoblastic and osteolytic metastases were determined by using CT as the reference standard. The metastases-to-vertebral body signal intensity ratio (MVR) was calculated to compare modalities. Phantom measurements were obtained to correlate bone densities between MRI sequences and CT. Results A total of 64 metastases (38 predominantly osteoblastic, 26 predominantly osteolytic) were detected. Susceptibility-weighted MRI achieved a sensitivity of 100% (38 of 38) and specificity of 96% (25 of 26) for predominantly osteoblastic metastases and a sensitivity of 96% (25 of 26) and specificity of 100% (38 of 38) for predominantly osteolytic metastases. Standard MRI sequences achieved a sensitivity of 89% (34 of 38) and specificity of 73% (19 of 26) for predominantly osteoblastic metastases and a sensitivity of 73% (19 of 26) and specificity of 92% (35 of 38) for predominantly osteolytic metastases. MVR measurements obtained with susceptibility-weighted MRI demonstrated a strong correlation with those obtained with CT (R² = 0.75), whereas those obtained with T1-weighted MRI, T2-weighted MRI, and turbo inversion-recovery magnitude MRI showed a weak to moderate correlation (R² = 0.00, R² = 0.35, and R² = 0.39, respectively). Susceptibility-weighted MRI showed a strong correlation with CT with regard to metastases size (R² = 0.91). In phantom measurements, susceptibility-weighted MRI enabled the reliable differentiation of different degrees of mineralization (R² = 0.92 compared with CT). Conclusion Susceptibility-weighted MRI enables the reliable differentiation between predominantly osteoblastic and osteolytic spine metastases with a higher accuracy than standard MRI sequences. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Schweitzer in this issue.

[68Ga]PSMA-HBED-CC Uptake in Osteolytic, Osteoblastic, and Bone Marrow Metastases of Prostate Cancer Patients

PURPOSE

The aim of this study was to evaluate potential differences in "Glu-NH-CO-NH-Lys" radio-labeled with [⁶⁸Ga]gallium N,N-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N-diacetic acid ([⁶⁸Ga]PSMA-HBED-CC) uptake in osteolytic, osteoblastic, mixed, and bone marrow metastases in prostate cancer (PC) patients.

PROCEDURES

This retrospective study was approved by the local ethics committee. Patients who received [⁶⁸Ga]PSMA-HBED-CC positron emission tomography/computed tomography ([⁶⁸Ga]PSMA-PET/CT) with at least one positive bone metastasis were included in this study. Only patients who have not received systemic therapy for their PC were included. Bone metastases had to be confirmed by at least one other imaging modality or follow-up investigation. The maximum standardized uptake value (SUV_max) and mean Hounsfield units (HU_mean) of each metastasis were measured. Based on CT, each metastasis was classified as osteolytic (OL), osteoblastic (OB), bone marrow (BM), or mixed (M).

RESULTS

One hundred fifty-four bone metastases in 30 patients were evaluated. Eighty out of 154 (51.9%) metastases were classified as OB, 21/154 (13.6%) as OL, 23/154 (14.9%) as M, and 30/154 (19.5%) as BM. The SUV_max for the different types of metastases were 10.6 ± 7.07 (OB), 24.0 ± 19.3 (OL), 16.0 ± 21.0 (M), and 14.7 ± 9.9 (BM). The SUV_max of OB vs. OL and OB vs. BM metastases differed significantly (p ≤ 0.025). A significant negative correlation between HU_mean and SUV_max (r = -0.23, p < 0.05) was measured.

CONCLUSIONS

[⁶⁸Ga]PSMA-HBED-CC uptake is higher in osteolytic and bone marrow metastases compared to osteoblastic metastases. Information derived from [⁶⁸Ga]PSMA-PET and CT complement each other for the reliable diagnosis of the different types of bone metastases in PC patients.

68 Ga-PSMA PET/CT for the detection of bone metastases in prostate cancer: a systematic review of the published literature

BACKGROUND

68 Ga-labelled prostate-specific membrane antigen (PSMA) is a promising PET ligand for the detection of prostate cancer. Little attention has been given to the ability of 68 Ga-PSMA PET/CT to detect malignant bone lesions and whether this approach is superior to existing bone imaging modalities.

AIM

To review the existing data of 68 Ga-PSMA PET/CT for the diagnosis of bone metastases in prostate cancer.

METHODS

Systematic review of the peer-reviewed literature.

RESULTS

Among 1858 papers in the original search, 37 papers were included in the analysis (six case reports and 31 case series). The vast majority of the studies were low-level evidence studies. Most studies presented data on detection rates without a reference standard. All but two studies were of a retrospective nature. Several cohort studies showed bone metastasis in 5-60% of patients with prostate cancer, including in patients with very low-PSA values. For primary staging, 68 Ga-PSMA PET/CT outperformed bone scans, while the superiority of 68 Ga-PSMA PET/CT compared with bone scans with respect to biochemical recurrence and metastatic castration-resistant prostate cancer (mCRPC) remains to be demonstrated.

CONCLUSION

68 Ga-PSMA PET/CT has shown to be a promising technique for use in prostate cancer. 68 Ga-PSMA PET/CT shows more lesions than bone scans, but data on diagnostic performance are very limited and indicate improved diagnostic performance in primary staging but not in mCRPC. Properly designed studies are needed to clarify the diagnostic performance of 68 Ga-PSMA PET/CT as well as its superiority over existing methods before 68 Ga-PSMA PET/CT can be routinely used for bone imaging.

Bone Pain and Muscle Weakness in Cancer Patients

PURPOSE OF REVIEW

In this article, we will discuss the current understanding of bone pain and muscle weakness in cancer patients. We will describe the underlying physiology and mechanisms of cancer-induced bone pain (CIBP) and cancer-induced muscle wasting (CIMW), as well as current methods of diagnosis and treatment. We will discuss future therapies and research directions to help patients with these problems.

RECENT FINDINGS

There are several pharmacologic therapies that are currently in preclinical and clinical testing that appear to be promising adjuncts to current CIBP and CIMW therapies. Such therapies include resiniferitoxin, which is a targeted inhibitor of noceciptive nerve fibers, and selective androgen receptor modulators, which show promise in increasing lean mass. CIBP and CIMW are significant causes of morbidity in affected patients. Current management is mostly palliative; however, targeted therapies are poised to revolutionize how these problems are treated.

Thoracic Temporal Subtraction Three Dimensional Computed Tomography (3D-CT): Screening for Vertebral Metastases of Primary Lung Cancers

PURPOSE

We developed an original, computer-aided diagnosis (CAD) software that subtracts the initial thoracic vertebral three-dimensional computed tomography (3D-CT) image from the follow-up 3D-CT image. The aim of this study was to investigate the efficacy of this CAD software during screening for vertebral metastases on follow-up CT images of primary lung cancer patients.

MATERIALS AND METHODS

The interpretation experiment included 30 sets of follow-up CT scans in primary lung cancer patients and was performed by two readers (readers A and B), who each had 2.5 years' experience reading CT images. In 395 vertebrae from C6 to L3, 46 vertebral metastases were identified as follows: osteolytic metastases (n = 17), osteoblastic metastases (n = 14), combined osteolytic and osteoblastic metastases (n = 6), and pathological fractures (n = 9). Thirty-six lesions were in the anterior component (vertebral body), and 10 lesions were in the posterior component (vertebral arch, transverse process, and spinous process). The area under the curve (AUC) by receiver operating characteristic (ROC) curve analysis and the sensitivity and specificity for detecting vertebral metastases were compared with and without CAD for each observer.

RESULTS

Reader A detected 47 abnormalities on CT images without CAD, and 33 of them were true-positive metastatic lesions. Using CAD, reader A detected 57 abnormalities, and 38 were true positives. The sensitivity increased from 0.717 to 0.826, and on ROC curve analysis, AUC with CAD was significantly higher than that without CAD (0.849 vs. 0.902, p = 0.021). Reader B detected 40 abnormalities on CT images without CAD, and 36 of them were true-positive metastatic lesions. Using CAD, reader B detected 44 abnormalities, and 39 were true positives. The sensitivity increased from 0.783 to 0.848, and AUC with CAD was nonsignificantly higher than that without CAD (0.889 vs. 0.910, p = 0.341). Both readers detected more osteolytic and osteoblastic metastases with CAD than without CAD.

CONCLUSION

Our temporal 3D-CT subtraction CAD software easily detected vertebral metastases on the follow-up CT images of lung cancer patients regardless of the osteolytic or osteoblastic nature of the lesions.

Quantitative imaging methods in osteoporosis

Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.