Imaging of malignant skeletal tumors

Osteosarcoma: a review of current and future therapeutic approaches

Osteosarcoma (OS) is the most common primary bone malignancy that affects children and young adults. OS is characterized by a high degree of malignancy, strong invasiveness, rapid disease progression, and extremely high mortality rate; it is considered as a serious threat to the human health globally. The incidence of OS is common in the metaphysis of long tubular bones, but rare in the spine, pelvis, and sacrum areas; moreover, majority of the OS patients present with only a single lesion. OS has a bimodal distribution pattern, that is, its incidence peaks in the second decade of life and in late adulthood. We examine historical and current literature to present a succinct review of OS. In this review, we have discussed the types, clinical diagnosis, and modern and future treatment methods of OS. The purpose of this article is to inspire new ideas to develop more effective therapeutic options.

Diagnostic performance of magnetic resonance imaging in the assessment of periosteal reactions in bone sarcomas using conventional radiography as the reference

Objective:

To evaluate the performance of magnetic resonance imaging (MRI) in detecting periosteal reactions and to compare MRI and conventional radiography (CR) in terms of the classification of periosteal reactions.

Materials and Methods:

Retrospective study of 42 consecutive patients (mean age, 22 years; 20 men) with a confirmed diagnosis of osteosarcoma or Ewing's sarcoma, MRI and CR images having been acquired pretreatment. Three blinded radiologists detected periosteal reactions and evaluated each periosteal reaction subtype in CR and MRI images: Codman's triangle; laminated; and spiculated. The CR was used as a benchmark to calculate the diagnostic performance. We used the kappa coefficient to assess interobserver reproducibility. A two-tailed Fisher's exact test was used in order to assess contingency between CR and MRI classifications.

Results:

In the detection of periosteal reactions, MRI showed high specificity, a high negative predictive value, and low-to-moderate sensitivity. For CR and for MRI, the interobserver agreement for periosteal reaction was almost perfect, whereas, for the classification of different subtypes of periosteal reaction, it was higher for the Codman's triangle subtype and lower for the spiculated subtype. There was no significant difference between MRI and CR in terms of the classifications (p < 0.05).

Conclusion:

We found no difference between MRI and CR in terms of their ability to classify periosteal reactions. MRI showed high specificity and almost perfect interobserver agreement for the detection of periosteal reactions. The interobserver agreement was variable for the different subtypes of periosteal reaction.

Imaging of soft tissue and osseous sarcomas of the extremities

Soft tissue and osseous sarcomas of the extremities are uncommon malignancies that represent very important diagnostic entities because of their aggressive nature. Radiologic investigations, including plain film, computed tomography, contrast-enhanced magnetic resonance imaging; scintigraphy, ultrasound, and positron emission tomography-computed tomography, play critical roles in providing a differential, establishing the diagnosis, demonstrating prognostic characteristics, and tailoring tumor treatment. The purpose of this review is to describe the most common soft tissue and osseous sarcomas of the extremities, with emphasis on their plain film and magnetic resonance imaging characteristics with the aim of aiding the reader to accurately describe the important imaging features and generate an appropriate differential diagnosis to aid the referring clinician with prompt appropriate management and treatment.

Incidence of contrast-induced nephropathy in patients with multiple myeloma undergoing contrast-enhanced CT

OBJECTIVE

The purpose of this article is to evaluate the incidence of contrast-induced nephropathy (CIN) and the effects of associated risk factors in patients with multiple myeloma undergoing contrast-enhanced CT (CECT) with IV administration of nonionic iodinated contrast agent.

MATERIALS AND METHODS

This retrospective review of medical records identified patients with a diagnosis of myeloma who underwent a CECT examination of the chest, abdomen, or pelvis between January 1, 2005, and December 1, 2008. Analysis for CIN, as defined by an increase in creatinine level after the CECT examination of 25% or more, or of 0.5 mg/dL, compared with the level before the CECT examination, both within 48 hours and within 7 days, was performed. Statistical correlations between the development of CIN and creatinine level before CECT examination, patient location, type and amount of contrast agent, blood urea nitrogen-creatinine ratio, history of diabetes, hypercalcemia, Bence Jones proteinuria, β(2)-microglobulin level, albumin level, International Myeloma Staging System stage, and history of myeloma provided at the time the CT examination was ordered were calculated.

RESULTS

Forty-six patients who completed 80 unique examinations were included; their average creatinine level before CECT examination was 0.97 mg/dL. There was no significant difference in the average creatinine levels before CT examination between patients without and those with CIN. Four (5%) and 12 (15%) patients developed CIN within 48 hours and 7 days, respectively. Only serum β(2)-microglobulin level showed a statistically significant (p = 0.03) correlation with the development of CIN.

CONCLUSION

The incidence of CIN in patients with multiple myeloma with a normal creatinine level is low and correlates with β(2)-microglobulin levels. The administration of contrast agent in this patient population is safe but should be based on the potential benefit of the examination and the expected low risk of developing CIN.

Imaging pediatric bone sarcomas

Primary malignant bone tumors are rare and account for about 6% of all new pediatric cancer cases per year in the United States. Identification of the lesion not uncommonly occurs as a result of imaging performed for trauma. Clinical and standard imaging characteristics of the various tumor types are evolving in concert with treatment advancements and clinical trial regimens. This article reviews the 3 most common pediatric bone sarcomas-osteosarcoma, Ewing sarcoma, and chondrosarcoma-and their imaging as applicable to contemporary disease staging and monitoring, and explores the roles of evolving imaging techniques.