This is the current release of the guideline.

This guideline updates a previous version: Morrison WB, Dalinka MK, Daffner RH, DeSmet AA, El-Khoury GY, Kneeland JB WB, Manaster BJ, Pavlov BN, Rubin DA, Schneider R, Steinbach LS, Weissman BN, Haralson RH, Expert Panel on Musculoskeletal Imaging. Bone tumors. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 5 p. [25 references]

The appropriateness criteria are reviewed biennially and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

Bone tumors

To evaluate the appropriateness of initial radiologic examinations for bone tumors

Utility of radiologic examinations in differential diagnosis

Literature Search Procedure

The Medline literature search is based on keywords provided by the topic author. The two general classes of keywords are those related to the condition (e.g., ankle pain, fever) and those that describe the diagnostic or therapeutic intervention of interest (e.g., mammography, MRI).

The search terms and parameters are manipulated to produce the most relevant, current evidence to address the American College of Radiology Appropriateness Criteria (ACR AC) topic being reviewed or developed. Combining the clinical conditions and diagnostic modalities or therapeutic procedures narrows the search to be relevant to the topic. Exploding the term "diagnostic imaging" captures relevant results for diagnostic topics.

The following criteria/limits are used in the searches.

1. Articles that have abstracts available and are concerned with humans.
2. Restrict the search to the year prior to the last topic update or in some cases the author of the topic may specify which year range to use in the search. For new topics, the year range is restricted to the last 5 years unless the topic author provides other instructions.
3. May restrict the search to Adults only or Pediatrics only.
4. Articles consisting of only summaries or case reports are often excluded from final results.

The search strategy may be revised to improve the output as needed.

The total number of source documents identified as the result of the literature search is not known.

Strength of Evidence Key

Category 1 - The conclusions of the study are valid and strongly supported by study design, analysis, and results.

Category 2 - The conclusions of the study are likely valid, but study design does not permit certainty.

Category 3 - The conclusions of the study may be valid, but the evidence supporting the conclusions is inconclusive or equivocal.

Category 4 - The conclusions of the study may not be valid because the evidence may not be reliable given the study design or analysis.

The topic author drafts or revises the narrative text summarizing the evidence found in the literature. American College of Radiology (ACR) staff draft an evidence table based on the analysis of the selected literature. These tables rate the strength of the evidence for all articles included in the narrative text.

The expert panel reviews the narrative text, evidence table, and the supporting literature for each of the topic-variant combinations and assigns an appropriateness rating for each procedure listed in the table. Each individual panel member forms his/her own opinion based on his/her interpretation of the available evidence.

More information about the evidence table development process can be found in the ACR Appropriateness Criteria® Evidence Table Development document (see "Availability of Companion Documents" field).

Modified Delphi Technique

When the data available from existing scientific studies are insufficient, the American College of Radiology Appropriateness Criteria (ACR AC) employs systematic consensus techniques to determine appropriateness. The ACR AC panels use a modified Delphi technique to determine the rating for a specific procedure. A series of surveys are conducted to elicit each individual panelist's expert opinion of the appropriateness of an imaging or therapeutic procedure for a specific clinical scenario based on the available data. ACR staff distributes surveys to the panelists along with the evidence table and narrative. Each panelist interprets the available evidence and rates each procedure. Voting surveys are completed by panelists without consulting other panelists. The ratings are integers on a scale between 1 and 9, where 1 means the panel member feels the procedure is "least appropriate" and 9 means the panel member feels the procedure is "most appropriate." Each panel member has one vote per round to assign a rating. The surveys are collected and de-identified and the results are tabulated and redistributed after each round. A maximum of three rounds are conducted. The modified Delphi technique enables each panelist to express individual interpretations of the evidence and his or her expert opinion without excessive bias from fellow panelists in a simple, standardized, and economical process.

Consensus among the panel members must be achieved to determine the final rating for each procedure. If eighty percent (80%) of the panel members agree on a single rating or one of two consecutive ratings, the final rating is determined by the rating that is closest to the median of all the ratings. Up to three voting rounds are conducted to achieve consensus.

If consensus is not reached through the modified Delphi technique, the panel is convened by conference call. The strengths and weaknesses of each imaging examination or procedure are discussed and a final rating is proposed. If the panelists on the call agree, the rating is accepted as the panel's consensus. The document is circulated to all the panelists to make the final determination. If consensus cannot be reached, "No consensus" appears in the rating column and the reasons for this decision are added to the comment sections.

Not applicable

A formal cost analysis was not performed and published cost analyses were not reviewed.

Criteria developed by the Expert Panels are reviewed by the American College of Radiology (ACR) Committee on Appropriateness Criteria.

Note from the American College of Radiology (ACR) and the National Guideline Clearinghouse (NGC): ACR has updated its Relative Radiation Level categories and Rating Scale. The Rating Scale now includes categories (1,2,3 = Usually not appropriate; 4,5,6 = May be appropriate; 7,8,9 = Usually appropriate). See the original guideline document for details.

ACR Appropriateness Criteria®

Clinical Condition: Primary Bone Tumors

Variant 1: Screening, first study.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 2: Persistent symptoms, but radiograph negative.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 3: Definitively benign on radiographs (excluding osteoid osteoma).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 4: Clinically suspected osteoid osteoma.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 5: Suspicious for malignant characteristics on radiograph.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Summary of Literature Review

There are numerous imaging techniques for evaluating bone tumors. However, the routine radiograph remains the primary screening technique and is the least expensive for detection and histologic characterization of many tumor or tumor-like conditions of bone. When a classically nonaggressive lesion is detected on routine radiographs, additional studies may not be required unless surgical intervention is contemplated and further anatomic information is required. In this setting, either computed tomography (CT) or magnetic resonance imaging (MRI) may be most appropriate for preoperative evaluation.

Magnetic Resonance Imaging and Computed Tomography

When routine radiographic features are indeterminate or the lesion is more aggressive and considered to be potentially malignant, additional imaging studies are frequently required. In the past, radionuclide imaging was used to evaluate bone lesions in this setting. However, today, because of MRI's improved anatomic detail and sensitivity, it is preferred over radionuclide studies. Early evaluation of MRI and CT demonstrated that MRI was superior for staging of bone tumors before treatment. One study described MRI and CT features of bone tumors with regard to cortical bone destruction and marrow, soft-tissue, joint, and neurovascular involvement. Another study reported that MRI was superior to CT for cortical bone destruction in 4.5% of patients studied, for marrow involvement in 25%, for soft-tissue involvement in 31%, for joint involvement in 36.4%, and for invasion of neurovascular structures in 15.3% of patients studied. In the same categories, MRI and CT were felt to be equal in 63% to 82% of patients. CT was superior to MRI for cortical bone destruction in 13.6% of patients and neurovascular involvement in 7.7% of patients.

In most institutions, the choice of imaging technique depends on patient status as well as the location and type of suspected lesion. MRI is most typically used for staging lesions in the extremities. MR spectroscopy has potential to differentiate benign from malignant lesions, but more research is needed. CT is usually preferred when tumors are located within the periosteal or cortical regions, with flat bones with thin cortex and little marrow, and to better demonstrate tumor mineralization, which may be suspected from routine radiographs. For rib lesions, thin-section CT is useful to exclude fracture through a nonaggressive lesion. CT is also preferred over MRI for detecting a characteristic central nidus in patients with suspected osteoid osteoma on radiographs.

Positron Emission Tomography

Positron emission tomography (PET) scanning has been used with success for detecting metabolically active metastatic lesions or recurrences and for preoperative evaluation of known sarcomas. PET has also shown promise in helping differentiate benign from malignant bone lesions. However, although studies have found significant differences in the average SUVmax (maximum standard uptake value) between benign and malignant groups, there is significant overlap in individual tumor types, reflecting variegated metabolic activity in different lesions and complicating myxoid and necrotic components with low metabolic activity. Studies have predominantly been performed on mixed lesion types, with low numbers of individual entities that could provide information regarding evaluation of specific tumor types for malignant potential. A group of authors have found that PET with fluorine-18-2-fluoro-2-deoxy-D-glucose tracer (FDG-PET) can help differentiate benign from malignant spinal compression fractures, with a sensitivity of 86% and specificity of 83%; however, there was overlap in the range of SUV in the benign and malignant groups. Also, there have been reports of nontumor conditions (especially inflammatory entities) that can also result in abnormal uptake.

The role of PET scanning in the workup of bone tumors has yet to be established. A lesion with indeterminate aggressiveness on radiographs with little to no increased uptake on PET scan could potentially undergo more conservative follow-up; however, more research is required in this regard. It seems clear that PET can provide more information, especially in patients who cannot undergo MRI and in situations where biopsy is not feasible due to location or patient condition. It can also be used to help plan biopsy, with PET/CT fusion images used to target areas with more cellular metabolic activity that may give higher diagnostic yield.

Ultrasound

While focused musculoskeletal ultrasound (US) with Doppler flow analysis can be a useful tool with some primary osseous and soft-tissue tumors, it is not considered a first-line modality. It should be considered when the size of the lesion renders imaging with pre–contrast enhanced and post–contrast enhanced MRI incomplete, or when assessment of echotexture and vascularity might decrease the size of the differential after assessment with MRI and CT is complete. However, such a US assessment requires a skilled sonographer, and there is little in the medical literature describing differentiating characteristics of musculoskeletal tumors on US.

Chondroid Lesions

There are special considerations when dealing with suspected chondroid lesions. Intramedullary chondroid lesions appearing in the hands and feet are nearly always benign, and may present incidentally or as a pathological fracture. If the lesion is elsewhere, it may be challenging by any imaging modality to differentiate a benign lesion from a low-grade malignancy. If there is pain related to the lesion, suspicion of malignancy should be high. One study suggests that imaging features including deep endosteal scalloping, cortical destruction, soft-tissue mass (on CT or MRI), periosteal reaction (on radiographs), and marked uptake of radionuclide can be used to distinguish appendicular enchondroma from chondrosarcoma in at least 90% of cases. Another study suggests that radiographic signs cannot discriminate reliably between enchondroma and grade 1 chondrosarcoma, but that axial location and large size (greater than 5 cm) are the most reliable predictors of malignancy in this setting. An additional study suggests that dynamic contrast-enhanced MRI can assist in differentiating benign from malignant chondroid lesions, and other authors suggest that PET may be useful; however, these modalities have not been clearly established for this purpose. Protocol for follow-up of an asymptomatic, incidentally identified lesion has not been scientifically established. Some authors suggest that the risk of malignant transformation is increased for larger lesions, for lesions in the axial skeleton, and in the setting of multiple lesions (e.g., Ollier's disease). They suggest radiographic follow-up for those with higher risk but stop short of making specific recommendations regarding interval and extent of follow-up.

Other Imaging Modalities

Patients with symptoms related to the bone or joint with normal radiographs present a different problem. Though CT may be performed in this setting, a radionuclide bone scan may be more useful to localize the abnormality. MRI can be very useful in this setting not only to identify whether a lesion is present but also to define the nature of a lesion based on the features discussed above; as a result, MRI is generally preferred. If an osteoid osteoma is suspected, one study reported that CT was more accurate than MRI in 63% of cases. However, another study reported that dynamic contrast-enhanced MRI can improve conspicuity of osteoid osteoma compared to CT.

Other invasive imaging techniques, such as angiography, are not commonly required. One study compared MRI, CT, technetium-99m bone scans, and angiography for local staging of 56 patients with primary bone sarcomas. This study demonstrated that MRI was superior to CT and scintigraphy in defining the extent of bone involvement and was equal in accuracy to CT in demonstrating joint and cortical involvement. CT, MRI, and angiography were compared for evaluating neurovascular involvement. CT demonstrated a sensitivity of 33%, MRI 100%, and angiography 83%, with specificities of 93% for CT, 98% for MR, and 71% for angiography. This study concluded that MRI is the technique of choice for evaluating and staging primary bone sarcomas, including neurovascular involvement. MRI is useful for determining tissue characteristics of a bone lesion, such as fat, hemorrhage, fibrous tissue, or fluid levels. With gadolinium contrast, cystic or necrotic areas can be detected.

Summary

• Routine radiographs remain the optimal screening technique for primary bone tumors.
• When lesions are characteristically nonaggressive, additional imaging may not be required unless needed for preoperative planning. The data suggest that MRI is the preferred technique for staging of primary bone neoplasms but in some categories CT is equal or superior to MRI.
• CT is preferred for patients with suspected osteoid osteoma or subtle cortical abnormalities, and for evaluating matrix mineralization.
• Advanced imaging modalities provide complementary information, and often more than one is required for diagnostic or preprocedure evaluation.

Anticipated Exceptions

Nephrogenic systemic fibrosis (NSF) is a disorder with a scleroderma-like presentation and a spectrum of manifestations that can range from limited clinical sequelae to fatality. It appears to be related to both underlying severe renal dysfunction and the administration of gadolinium-based contrast agents. It has occurred primarily in patients on dialysis, rarely in patients with very limited glomerular filtration rate (GFR) (i.e., <30 mL/min/1.73 m²), and almost never in other patients. There is growing literature regarding NSF. Although some controversy and lack of clarity remain, there is a consensus that it is advisable to avoid all gadolinium-based contrast agents in dialysis-dependent patients unless the possible benefits clearly outweigh the risk, and to limit the type and amount in patients with estimated GFR rates <30 mL/min/1.73 m². For more information, please see the American College of Radiology (ACR) Manual on Contrast Media (see the "Availability of Companion Documents" field).

Abbreviations

• CT, computed tomography
• FDG-PET, fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography
• Med, medium
• MRI, magnetic resonance imaging
• NS, not specified
• Tc, technetium
• US, ultrasound

Algorithms were not developed from criteria guidelines.

The recommendations are based on analysis of the current literature and expert panel consensus.

Selection of appropriate radiologic imaging procedures to evaluate patients with bone tumors or suspected of bone tumors

Gadolinium-based Contrast Agents

Nephrogenic systemic fibrosis (NSF) is a disorder with a scleroderma-like presentation and a spectrum of manifestations that can range from limited clinical sequelae to fatality. It appears to be related to both underlying severe renal dysfunction and the administration of gadolinium-based contrast agents. It has occurred primarily in patients on dialysis, rarely in patients with very limited glomerular filtration rate (GFR) (i.e., <30 mL/min/1.73 m²), and almost never in other patients. Although some controversy and lack of clarity remain, there is a consensus that it is advisable to avoid all gadolinium-based contrast agents in dialysis-dependent patients unless the possible benefits clearly outweigh the risk, and to limit the type and amount in patients with estimated GFR rates <30 mL/min/1.73 m². For more information, please see the American College of Radiology (ACR) Manual on Contrast Media (see the "Availability of Companion Documents" field).

Relative Radiation Level (RRL)

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, an RRL indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria® Radiation Dose Assessment Introduction document (see "Availability of Companion Documents" field).

The American College of Radiology (ACR) Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists, and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient's clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those exams generally used for evaluation of the patient's condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the U.S. Food and Drug Administration (FDA) have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

The American College of Radiology (ACR) provided the funding and the resources for these ACR Appropriateness Criteria®.

Committee on Appropriateness Criteria, Expert Panel on Musculoskeletal Imaging

Panel Members: William B. Morrison, MD (Principal Author); Adam C. Zoga, MD (Research Author); Richard H. Daffner, MD (Panel Chair); Barbara N. Weissman, MD (Panel Vice-Chair); Laura Bancroft, MD; D. Lee Bennett, MD; Judy S. Blebea, MD; Ian Blair Fries, MD; Jon A. Jacobson, MD; William K. Payne, MD; Charles S. Resnik, MD; Catherine C. Roberts, MD; Mark E. Schweitzer, MD; Leanne L. Seeger, MD; Mihra Taljanovic, MD; James N. Wise, MD

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Morrison WB, Dalinka MK, Daffner RH, DeSmet AA, El-Khoury GY, Kneeland JB WB, Manaster BJ, Pavlov BN, Rubin DA, Schneider R, Steinbach LS, Weissman BN, Haralson RH, Expert Panel on Musculoskeletal Imaging. Bone tumors. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 5 p. [25 references]

The appropriateness criteria are reviewed biennially and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site.

Print copies: Available from the American College of Radiology, 1891 Preston White Drive, Reston, VA 20191. Telephone: (703) 648-8900.

The following are available:

• ACR Appropriateness Criteria®. Overview. Reston (VA): American College of Radiology; 2 p. Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site.
• ACR Appropriateness Criteria®. Literature search process. Reston (VA): American College of Radiology; 1 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Evidence table development. Reston (VA): American College of Radiology; 4 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Radiation dose assessment introduction. Reston (VA): American College of Radiology; 2 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria® Manual on contrast media. Reston (VA): American College of Radiology; 90 p. Electronic copies: Available in PDF from the ACR Web site.

None available

This summary was completed by ECRI on May 6, 2001. The information was verified by the guideline developer as of June 29, 2001. This summary was updated by ECRI on March 27, 2006. This summary was updated by ECRI Institute on May 17, 2007 following the U.S. Food and Drug Administration (FDA) advisory on Gadolinium-based contrast agents. This summary was updated by ECRI Institute on June 20, 2007 following the U.S. Food and Drug Administration (FDA) advisory on gadolinium-based contrast agents. This summary was updated by ECRI Institute on May 21, 2010. This summary was updated by ECRI Institute on January 13, 2011 following the U.S. Food and Drug Administration (FDA) advisory on gadolinium-based contrast agents.

Instructions for downloading, use, and reproduction of the American College of Radiology (ACR) Appropriateness Criteria® may be found on the ACR Web site .