Applications of PET/CT and PET/MR Imaging in Primary Bone Malignancies

Multimodal positron emission tomography (PET) imaging in non-oncologic musculoskeletal radiology

Musculoskeletal (MSK) disorders are associated with large impacts on patient's pain and quality of life. Conventional morphological imaging of tissue structure is limited in its ability to detect pain generators, early MSK disease, and rapidly assess treatment efficacy. Positron emission tomography (PET), which offers unique capabilities to evaluate molecular and metabolic processes, can provide novel information about early pathophysiologic changes that occur before structural or even microstructural changes can be detected. This sensitivity not only makes it a powerful tool for detection and characterization of disease, but also a tool able to rapidly assess the efficacy of therapies. These benefits have garnered more attention to PET imaging of MSK disorders in recent years. In this narrative review, we discuss several applications of multimodal PET imaging in non-oncologic MSK diseases including arthritis, osteoporosis, and sources of pain and inflammation. We also describe technical considerations and recent advancements in technology and radiotracers as well as areas of emerging interest for future applications of multimodal PET imaging of MSK conditions. Overall, we present evidence that the incorporation of PET through multimodal imaging offers an exciting addition to the field of MSK radiology and will likely prove valuable in the transition to an era of precision medicine.

Bone tumors: state-of-the-art imaging

Imaging plays a central role in the management of patients with bone tumors. A number of imaging modalities are available, with different techniques having unique applications that render their use advantageous for various clinical purposes. Coupled with detailed clinical assessment, radiological imaging can assist clinicians in reaching a proper diagnosis, determining appropriate management, evaluating response to treatment, and monitoring for tumor recurrence. Although radiography is still the initial imaging test of choice for a patient presenting with a suspected bone tumor, technological innovations in the last decades have advanced the role of other imaging modalities for assessing bone tumors, including advances in computed tomography, magnetic resonance imaging, scintigraphy, and hybrid imaging techniques that combine two existing modalities, providing clinicians with diverse tools for bone tumor imaging applications. Determining the most suitable modality to use for a particular application requires familiarity with the modality in question, its advancements, and its limitations. This review highlights the various imaging techniques currently available and emphasizes the latest developments in imaging, offering a framework that can help guide the imaging of patients with bone tumors.

Augmenting CT-Guided Bone Biopsies Using 18F-FDG PET/CT Guidance

Computer tomography (CT)-guided percutaneous core biopsies are currently the gold standard in diagnostic procedures for patients with bone lesions of unknown kind. CT-guided biopsies can lead to misdiagnosis or repetition of biopsies in case of small or heterogeneous lesions. We hypothesize that molecular image guidance could be used to optimize the biopsy strategy, by supporting the detection of heterogeneous lesions or lesions without radiographic substrate. To evaluate this hypothesis, we investigated if and how the addition of 2-deoxy-2-18F-fluoro-D-glucose-positron emission tomography (18F-FDG-PET)/CT could augment routine CT-guided bone biopsies. To this end, 106 patients who underwent a CT-guided bone biopsy between April 2019 and April 2020, obtained from either a vertebral or peripheral bone, were included. Patients were divided into 2 groups: 36 patients received an 18F-FDG-PET/CT scan prior to their CT-guided bone biopsy (PET group), while 70 patients only had a morphological CT scan (CT group). Histopathology was used to categorize biopsies into five subgroups (inconclusive, benign, malignant or infectious disease, or normal tissue). In the PET group, the number of conclusive biopsies was significantly higher compared to the CT group (N = 33/36 (92%) versus N = 53/70 (76%); p < 0.05). Furthermore, the number of first-try biopsies was lower in the PET group compared to the CT group (1.9 vs. 2.54, p = 0.051). In conclusion, 18F-FDG-PET/CT imaging significantly increased the success rate of first-try CT-guided bone biopsies by showing less inconclusive biopsies and misdiagnosis.

Case report: When infection lurks behind malignancy: a unique case of primary bone lymphoma mimicking infectious process in the spine

Primary bone lymphoma of the spine (PBL) is a rare entity that may be misdiagnosed due to its atypical location and clinical and imaging features mimicking certain pathologies as infectious processes, which complicates and delays diagnosis. Our case reports a patient in her sixties who had been suffering from chronic low back pain for a year, and had gradually started to develop cruralgia. She underwent a blood sample, magnetic resonance imaging (MRI), and positron emission tomography (18F-FDG-PET/CT) which revealed inflammatory syndrome, and an image of spondylodiscitis of the lumbar spine associated with a morphological and metabolical widespread invasion posteriorly suggesting epiduritis. No other lesions were found on the rest of the body. Neurosurgical management was performed and a biopsy was made. Histological results showed aggressive and diffuse large B-cell lymphoma, suggesting a diagnosis of PBL. This case highlights the first case of spondylodiscitis mimicking PBL in the lumbar spine, the intricacies of the diagnostic work-up, and the complexity of discriminating with an infectious process in the spine, as both have a similar, non-specific clinical presentation, while morphological and metabolic findings can be alike.

Erdheim-Chester disease and nuclear medicine imaging. A case report and brief review

Erdheim-Chester disease (ECD) is a rare clonal myeloid neoplasm typically affecting adults over 50 years old, with bone lesions in almost all patients. The prognosis is poor in most cases if left untreated. Clinical manifestations are not specific, which hinders early diagnosis. The disease has distinct radiological features. However, three-phase bone scintigraphy exhibits the most typical pattern of all imaging modalities, which is the prominent strikingly symmetrical radiotracer uptake in the distal ends of the femurs and proximal and distal ends of the tibiae, sparing the epiphyses. We report a case of a 54-year-old female patient, presenting with atypical persistent knee joint pain. After an MRI scan, she underwent a three-phase bone scan, revealing the characteristic pattern, thus indicating a possible ECD diagnosis, which was eventually confirmed in biopsy material. Novel aspects of the pathophysiology and treatment of the disease, as well as a differential diagnosis from the perspective of an MSK radiologist and nuclear medicine physician, are also discussed.

Molecular Imaging with PET-CT and PET-MRI in Pediatric Musculoskeletal Diseases

Molecular imaging has emerged as an integral part of oncologic imaging. Given the physiologic changes that precede anatomic changes, molecular imaging can enable early detection of disease and monitoring of response. [18F] Fluorodeoxyglucose (FDG) Positron emission tomography (PET) is the predominant molecular imaging modality used in oncologic assessment and can be performed using PET/CT or PET/MR. In pediatric patients, PET/MRI imaging is generally preferred due to low radiation exposure and PET/MRI is particularly advantageous for imaging musculoskeletal (MSK) diseases, as MRI provides superior characterization of tissue changes as compared to CT. In this article, we provide an overview of the typical role of PET CT/MRI in assessment of some common pediatric malignancies and benign MSK diseases with case examples. We also discuss the relative advantages of PET/MRI compared to PET/CT, and review published data with a primary focus on the use of PET/MR.

Update on Positron Emission Tomography/Magnetic Resonance Imaging: Cancer and Inflammation Imaging in the Clinic

Hybrid PET/MRI is highly valuable, having made significant strides in overcoming technical challenges and offering unique advantages such as reduced radiation, precise data coregistration, and motion correction. Growing evidence highlights the value of PET/MRI in broad clinical aspects, including inflammatory and oncological imaging in adults, pregnant women, and pediatrics, potentially surpassing PET/CT. This newly integrated solution may be preferred over PET/CT in many clinical conditions. However, further technological advancements are required to facilitate its broader adoption as a routine diagnostic modality.

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.

18F-FDG PET/CT in the Management of Osteosarcoma

Osteosarcoma is the most common type of primary malignant bone tumor. ¹⁸F-FDG PET/CT is useful for staging, detecting recurrence, monitoring response to neoadjuvant chemotherapy, and predicting prognosis. Here, we review the clinical aspects of osteosarcoma management and assess the role of ¹⁸F-FDG PET/CT, in particular with regard to pediatric and young adult patients.

Update in Imaging Evaluation of Bone and Soft Tissue Sarcomas

The evolution in imaging evaluation of musculoskeletal sarcomas contributed to a significant improvement in the prognosis and survival of patients with these neoplasms. The precise characterization of these lesions, using the most appropriate imaging modalities to each clinical condition presented, is of paramount importance in the design of the therapeutic approach to be instituted, with a direct impact on clinical outcomes. The present article seeks to update the reader regarding imaging methodologies in the context of local and systemic evaluation of bone sarcomas and soft tissues.

Pathological fracture due to primary bone lymphoma in a patient with a history of prostate cancer: A case report and review of literature

Primary bone lymphoma (PBL) is a rare extranodal presentation within lymphomas and primary bone malignancies. Pathologic fracture (PF) is a common complication of metastatic bone disease but is, rarely, the presentation of a primary bone tumor. We report a case of an 83-year-old man with a history of untreated prostate cancer, presenting with atraumatic fracture of his left femur after months of intermittent pains and weight loss. Radiographic workup revealed a lytic lesion suspicious for PF secondary to metastatic prostate cancer; however, initial core biopsy results were inconclusive for malignancy. A complete blood count with differential and complete metabolic panel was within normal limits. During surgical fixation and nailing of the femur, a reaming biopsy was performed as a repeat measure and revealed diffuse large B-cell lymphoma. Staging with positron emission tomography and computed tomography found no evidence of lymphatic or visceral involvement and chemotherapy was promptly initiated. This case highlights the diagnostic workup challenges for PF secondary to PBL, especially in the setting of concurrent malignancy. Because of the non-specific presentation of a lytic lesion on imaging associated with atraumatic fracture, we highlight PBL as an important diagnostic consideration.

Primary Bone Lymphoma: A Review of the Literature with Emphasis on Histopathology and Histogenesis

Primary bone lymphoma (PBL) is a rare neoplasm of malignant lymphoid cells presenting with one or more bone lesions without nodal or other extranodal involvement. It accounts for approximately 1% of all lymphomas and 7% of malignant primary bone tumors. Diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) represents the predominant histological type and constitutes over 80% of all cases. PBL may occur at all ages with a typical diagnosis age of 45–60 years and a slight male predominance. Local bone pain, soft tissue edema, palpable mass and pathological fracture are the most common clinical features. Diagnosis of the disease, which is frequently delayed due to its non-specific clinical presentation, is based on the combination of clinical examination and imaging studies and confirmed by combined histopathological and immunohistochemical examination. PBL can develop in any part of the skeleton, although it occurs most commonly in the femur, humerus, tibia, spine and pelvis. The imaging appearance of PBL is highly variable and unspecific. In terms of the cell-of-origin, most cases of primary bone DLBCL (PB-DLBCL), NOS belong to the germinal center B-cell-like subtype and specifically originate from germinal center centrocytes. PB-DLBCL, NOS has been considered a distinct clinical entity based on its particular prognosis, histogenesis, gene expression and mutational profile and miRNA signature. PBL carries a favorable prognosis, especially when treated with combined chemoradiotherapy.

Whole body imaging in musculoskeletal oncology: when, why, and how

The use of whole-body imaging has become increasingly popular in oncology due to the possibility of evaluating total tumor burden with a single imaging study. This is particularly helpful in cases of widespread disease where dedicated regional imaging would make the evaluation more expensive, time consuming, and prone to more risks. Different techniques can be used, including whole-body MRI, whole-body CT, and PET-CT. Common indications include surveillance of cancer predisposing syndromes, evaluation of osseous metastases and clonal plasma cell disorders such as multiple myeloma, and evaluation of soft tissue lesions, including peripheral nerve sheath tumors. This review focuses on advanced whole-body imaging techniques and their main uses in musculoskeletal oncology.

Contribution of positron emission tomography/magnetic resonance imaging in musculoskeletal malignancies

Positron emission tomography/computed tomography (PET/CT) is a promising hybrid imaging technique for evaluating musculoskeletal malignancies. Both technologies, independently are useful for evaluating this type of tumors. PET/MR has great potential combining metabolic and functional imaging PET with soft tissue contrast and multiparametric sequences of MR. In this paper we review the existing literature and discuss the different protocols, new available radiotracers to conclude with the scarce evidence available the most useful/probable indications of the PET MR for the for musculoskeletal malignancies.

Primary spindle cell sarcoma of gallbladder: An unusual case report and a literature review

INTRODUCTION

Primary spindle cell sarcoma of the gallbladder is a rare condition.

PATIENT CONCERNS

A 67-year-old woman was admitted to a local hospital with a chief complaint of abdominal pain in the right upper quadrant for the past 2 months.

DIAGNOSIS AND INTERVENTION

Surgical resection was performed following the diagnosis of primary gallbladder sarcoma with local hepatic metastasis. Histological examination confirmed a diagnosis of primary spindle cell sarcoma and hepatic metastasis with simultaneous cholecystolithiasis.

OUTCOMES

Adjuvant chemoradiation therapy was not performed because the patient refused treatment. Three months after the surgery, a relapsed lesion was diagnosed. The patient underwent transcatheter arterial chemoembolization.

CONCLUSIONS

The disease should be differentially diagnosed from gallbladder carcinoma or carcinosarcoma with hepatic metastasis. An aggressive surgical approach should be based on a balance between the risk of surgery and the outcome.

Diagnostic performance of PET/CT in primary malignant bone tumors

Background

Nowadays, PET/CT plays a substantial role in the diagnosis of different types of tumor by its ability to provide combined functional and anatomic imaging in the same session. The purpose of this study is to evaluate the added value of PET/CT in staging and re-staging of primary malignant bone tumors.

Results

Out of the studied 40 patients, 7 patients were referred for primary staging of different types of histologically proven primary malignant bone tumors, their FDG-PET/CT studies yielded additional diagnostic information in 28.6% of them. Thirty three patients were referred either for assessment of treatment response or for follow-up to detect any viable lesions; FDG-PET/CT was more sensitive and specific than CT in follow-up and assessment of treatment response with PET/CT sensitivity 94.4%, specificity 86.7%, and total accuracy 90.9% and CT sensitivity 88.2%, specificity 81.2%, and total accuracy 84.8%.

Conclusions

PET/CT was an accurate imaging modality in evaluation of primary malignant bone tumors regarding tumor staging, assessment of therapeutic response and detection of metastatic disease as compared to CT.

Diagnosis and staging of malignant bone tumours in children: what is due and what is new?

PURPOSE

Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment.

METHODS

We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed.

RESULTS

History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings.

CONCLUSION

When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes.

LEVEL OF EVIDENCE

Level V Expert opinion.

Theranostic Agents in Musculoskeletal Disorders

Theranostic-based strategies, combining therapeutic and diagnostic properties of a single agent, have gained enormous attention in the past few years. Today, various multifunctional theranostic modalities have been examined, using different bioactive targeting, for the detection, quantifying, and monitoring of therapy response in different pathologies. Herein we review the newly emerging approaches in theranostic nanomedicine for the detection and therapy for musculoskeletal disorders to provide valuable insights for developing more efficient agents for clinical use. Some potential preclinical applications of radionuclide nanotheranostic agents are described in rheumatoid arthritis, osteoarthrosis, multiple myeloma, and neoplastic diseases.

An Approach to Undiagnosed Bone Tumors

The radiographic appearance of primary bone tumors is important for initial diagnosis and often augments histopathological analysis. The original grading system relied on the radiographic analysis of the margin of the lesions to determine tumor aggression, which often corresponds with malignant potential. The recently developed, modified Lodwick-Madewell grading system also incorporates the appearance of lesion margins on radiographs but also considers the change in margins on serial radiographs and includes a category for clinically suspected, radiographically occult, aggressive lesions. This article reviews the prior and modified grading systems, and the concepts necessary for proper interpretation of the initial appearance of bone tumors which often determines the radiologist's recommendation for biopsy or follow-up imaging.

Imaging of Soft Tissue Tumors

Differentiation of malignant from benign soft tissue tumors is challenging with imaging alone, including that by magnetic resonance imaging and computed tomography. However, the accuracy of this differentiation has increased owing to the development of novel imaging technology. Detailed patient history and physical examination remain essential for differentiation between benign and malignant soft tissue tumors. Moreover, measurement only of tumor size based on Response Evaluation Criteria In Solid Tumors criteria is insufficient for the evaluation of response to chemotherapy or radiotherapy. Change in metabolic activity measured by ¹⁸F-fluorodeoxyglucose positron emission tomography or dynamic contrast enhanced-derived quantitative endpoints can more accurately evaluate treatment response compared to change in tumor size. Magnetic resonance imaging can accurately evaluate essential factors in surgical planning such as vascular or bone invasion and "tail sign". Thus, imaging plays a critical role in the diagnosis and treatment of soft tissue tumors.

Role of bone marrow biopsy for staging new patients with Ewing sarcoma: A systematic review

The incidence of bone marrow metastasis (BMM) in newly diagnosed Ewing sarcoma (ES) is variable across studies. An optimal staging strategy for detecting BMM is not defined. While bone marrow (BM) biopsy and/or aspirate (BMBA) have been the gold standard, [F-18]fluorodeoxyglucose positron emission tomography (FDG-PET) to detect BMM may decrease reliance on BMBA. We conducted a systematic review to assess incidence of BMM and the role of FDG-PET. We observed a pooled incidence of BMM by BMBA of 4.8% in all newly diagnosed ES patients and 17.5% among patients with metastatic disease. Only 1.2% of patients had BMM as their sole metastatic site. FDG-PET detection of BMM compared to BMBA demonstrated pooled 100% sensitivity and 96% specificity, positive predictive value of 75%, and negative predictive value of 100%. In the era of FDG-PET imaging, omission of BMBA may be considered in patients with otherwise localized disease after initial staging studies.

Total-Body PET Imaging of Musculoskeletal Disorders

Imaging of musculoskeletal disorders, including arthritis, infection, osteoporosis, sarcopenia, and malignancies, is often limited when using conventional modalities such as radiography, computed tomography (CT), and MR imaging. As a result of recent advances in Positron Emission Tomography (PET) instrumentation, total-body PET/CT offers a longer axial field-of-view, higher geometric sensitivity, and higher spatial resolution compared with standard PET systems. This article discusses the potential applications of total-body PET/CT imaging in the assessment of musculoskeletal disorders.

Nuclear Medicine in the diagnosis of pathologies of the spine: role of hybrid imaging

Clinical problems in the human spine are still common in our society, often causing pain and can also limit movement. Back pain is a very common clinical entity, although difficult to diagnose due to its multifactorial nature. There are multiple processes that can alter the structure of the spine, injure vertebrae and/or the surrounding tissue. For the study of the spine, image diagnosis is essential, and within this, molecular hybrid techniques play an important role by providing us with an image of functional and morphological fusion. Among these, SPECT/CT is key in the diagnosis of traumatic and stress pathology, allowing us to locate hidden vertebral fractures, and is also very useful in degenerative and post-surgical pathology. On the other hand, PET/CT with 18F-FDG also plays an important role in the management and monitoring of infectious and oncological processes. This review describes the application of these hybrid techniques in the different pathologies of the spine and the findings of their images, being very useful for the diagnostic assessment and therapeutic management of the patient.

Belated Diagnosis of a Primary Bone Lymphoma of the Elbow: A Rare Case and Review of the Literature

Primary non-Hodgkin bone lymphoma (PBL) is a rare disease that accounts for &#x3c;2% of all lymphomas in adults. PBL can be monostotic or polyostotic, mainly causing destructive and lytic bone lesions frequently located in the femur, humerus, and pelvis. PBL is rarely considered a differential diagnosis of the osteolytic tumor. In addition, PBL is not uncommonly diagnosed with delay because patients do not experience symptoms nor show objective abnormalities in the early stage of disease. Here, we reported a 60-year-old woman with a PBL of the elbow.

The Spectrum of Rib Neoplasms in Adults: A Practical Approach and Multimodal Imaging Review

OBJECTIVE. Adult neoplasms of the ribs are a heterogeneous group consisting of both benign and aggressive entities. Rib neoplasms have a variety of overlapping imaging features, with much of the imaging data disjointed across the musculoskeletal, thoracic, and oncologic imaging literature. Arrival at accurate diagnosis can therefore be quite challenging. This article consolidates this information and introduces the reader to an algorithmic approach to rib lesion evaluation based on imaging. CONCLUSION. Rib neoplasms are a diverse group of benign and malignant entities, which often makes determining an accurate diagnosis challenging. Evaluation requires a multipronged approach that incorporates radiographic imaging features, nonradiographic imaging findings, lesion location, and clinical data.

Imaging Analyses of Bone Tumors

Despite the evolution in imaging, especially the introduction of advanced imaging technologies, radiographs still are the key for the initial assessment of a bone tumor. Important aspects to be considered in radiographs are the location, shape and size or volume, margins, periosteal reaction, and internal mineralization of the tumor's matrix; careful evaluation of these may provide for accurate diagnosis in >80% of cases. Computed tomography and magnetic resonance imaging are often diagnostic for lesions with typical findings such as the nidus of osteoid osteoma and bone destruction such as in Ewing sarcoma and lymphoma that may be difficult to detect with radiographs; they may also be used for surgical planning. Magnetic resonance imaging accurately determines the intraosseous extent and articular and vascular involvement by the tumor. This article summarizes the diagnostic accuracy of imaging analyses in bone tumors and emphasizes the specific radiographic findings for optimal radiographic diagnosis of the patients with these tumors.

The role of Thallium-201 scintigraphy and Tc-99m pentavalent dimercaptosuccinic acid in diagnosis and grading of chondrosarcoma

PURPOSE

Distinguishing between enchondromas and low-grade (grade 1) chondrosarcomas can be challenging. The aim of this study was to investigate the role of Thallium-201 scintigraphy and Technetium-99 m pentavalent dimercaptosuccinic acid (Tc-99 m DMSA (V)) in the diagnosis and grading of chondrosarcomas.

METHODS

232 consecutive patients with pathologically proven cartilaginous tumours between the years 2000 and 2018 were evaluated. We included 197 patients (101 males and 96 females; median age 50 years; range 15-86 years) who underwent Thallium-201(n = 193) and/or Tc-99 m DMSA (V) scanning (n = 67). Increased uptake was defined as uptake greater than background. The reference standard was the histopathological assessment based on a grading system (grade 1-3). Data was analysed using multivariate modelling.

RESULTS

There were 46 patients with enchondromas and 151 with chondrosarcomas. Of those, 64 (enchondroma n = 21, chondrosarcoma n = 43) underwent both Thallium-201 and Tc-99 m DMSA (V). Thallium-201 uptake had 7.92 times greater odds of grade 1 chondrosarcomas than enchondromas. Thallium-201 uptake was significantly associated with the odds of a higher grade chondrosarcoma (grade 2-3). DMSA (V) positivity was associated with 4.75 times the odds of a chondrosarcoma diagnosis over enchondroma (p = 0.024). DMSA (V) uptake revealed no association with chondrosarcoma grading.

CONCLUSION

Low-grade chondrosarcomas continue to pose a diagnostic dilemma. Thallium-201 scans may identify malignancy in benign appearing tumours as well as differentiate between low-grade and high-grade chondrosarcomas in said malignancies. DMSA (V) may be useful in distinguishing between benign and malignant entities as a whole.

New challenges in integrated diagnosis by imaging and osteo-immunology in bone lesions

INTRODUCTION

High-resolution imaging is the gold standard to measure the functional and biological features of bone lesions. Imaging markers have allowed the characterization both of tumour heterogeneity and metabolic data. Besides, ongoing studies are evaluating a combined use of 'imaging markers', such as SUVs, MATV, TLG, ADC from PET and MRI techniques respectively, and several 'biomarkers' spanning from chemokine immune-modulators, such as PD-1, RANK/RANKL, CXCR4/CXCL12 to transcription factors, such as TP53, RB1, MDM2, RUNX family, EZH2, YY1, MAD2. Osteoimmunology may improve diagnosis and prognosis leading to precision medicine in bone lesion treatment. Areas covered: We investigated modalities (molecular and imaging approach) useful to identify bone lesions deriving both from primary bone tumours and from osteotropic tumours, which have a higher incidence, prevalence and prognosis. Here, we summarized the recent advances in imaging techniques and osteoimmunology biomarkers which could play a pivotal role in personalized treatment. Expert commentary: Although imaging and molecular integration could allow both early diagnosis and stratification of cancer prognosis, large scale clinical trials will be necessary to translate pilot studies in the current clinical setting.

ABBREVIATIONS

ADC: apparent diffusion coefficient; ALCAM: Activated Leukocyte Cell Adhesion Molecule; ALP: Alkaline phosphatases; BC: Breast cancer; BSAP: B-Cell Lineage Specific Activator; BSAP: bone-specific alkaline phosphatase; BSP: bone sialoprotein; CRIP1: cysteine-rich intestinal protein 1; CD44: cluster of differentiation 44; CT: computed tomography; CXCL12: C-X-C motif ligand 12; CXCR4: C-X-C C-X-C chemokine receptor type 4; CTLA-4: Cytotoxic T-lymphocyte antigen 4; CTX-1: C-terminal end of the telopeptide of type I collagen; DC: dendritic cell; DWI: Diffusion-weighted MR image; EMT: mesenchymal transition; ET-1: endothelin-1; FDA: Food and Drug Administration; FDG: ¹⁸F-2-fluoro-2-deoxy-D-glucose; FGF: fibroblast growth factor; FOXC2: forkhead box protein C2: HK-2: hexokinase-2; ICTP: carboxyterminal cross-linked telopeptide of type I collagen; IGF-1R: Insulin Like Growth Factor 1 Receptor; ILC: innate lymphocytes cells; LC: lung cancer; IL-1: interleukin-1; LYVE1: lymphatic vessel endothelial hyaluronic acid receptor 1; MAD2: mitotic arrest deficient 2; MATV: metabolically active tumour volume; M-CSF: macrophage colony stimulating factor; MM: multiple myeloma; MIP1a: macrophage inflammatory protein 1a; MSC: mesenchymal stem cell; MRI: magnetic resonance imaging; PC: prostate cancer; NRP2: neuropilin 2; OPG: osteoprotogerin; PDGF: platelet-derived growth factor; PD-1: Programmed Cell Death 1; PET: positron emission tomography; PINP: procollagen type I N propeptide; PROX1: prospero homeobox protein 1; PSA: Prostate-specific antigen; PTH: parathyroid hormone; RANK: Receptor activator of NF-kB ligand; RECK: Reversion-inducing-cysteine-rich protein; SEMAs: semaphorins; SPECT: single photon computed tomography; SUV: standard uptake value; TLG: total lesion glycolysis; TP53: tumour protein 53; VCAM-1: vascular endothelial molecule-1; VOI: volume of interest; YY1: Yin Yang 1.