Magnetic Resonance Imaging for the Assessment of Long Bone Tumors

Abstract

Background:Wide resection margins of osseous tumors are associated with a low incidence of local recurrence, making accurate measurement of the intraosseous extent of primary malignant long bone tumors is crucial. We compared the intraosseous tumor extent assessed by magnetic resonance imaging (MRI) with the gross specimen to evaluate the accuracy of MRI.Methods:A total of 255 patients with primary malignant tumors in the long bones were included. Using MRI, we defined the length of tumor as the distance from the articular surface to the boundary between abnormal and normal marrow signal. The extent of the abnormal intraosseous signal was measured on unenhanced T1-weighted (T1WI) magnetic resonance images after chemotherapy. All gross surgical specimens were sectioned, and tumor extent was measured. Wilcoxon signed-rank test was used to test the differences between MRI and gross specimen findings. Spearman's correlation analysis was used to test the correlation between groups.Results:Median tumor length by gross specimen (112 mm; range, 45–300 mm) was longer than that by MRI (108 mm; range, 45–304 mm; Z = −6.916, P < 0.001). Of 255 images, tumor length was accurately represented on 27 T1WI magnetic resonance images, overestimated on 79 images, and underestimated on 149 images. The median difference between imaging and gross specimen measurements was 2.0 mm (range: 1.0–15.0 mm) for the 79 cases where tumor length was overestimated, and 5.0 mm (range: 1.0–18.0 mm) for the 149 cases where tumor length was underestimated. The Spearman correlation demonstrated a high correlation of tumor length on gross specimen with the tumor length on MRI (R = 0.99, P < 0.01).Conclusions:We conclude that preoperative MRI could be a useful method in determining intramedullary malignant bone tumor boundaries and may serve as an accepted assessment method of long bone tumors before limb-sparing surgery.

Comparison of MRI and Histopathology with regard to Intramedullary Extent of Disease in Bone Sarcomas

“…In their study, estimation of tumor length was done on gross specimens whereas we had histopathology confirmation confirming the pathologic extent of disease as well. Tao et al showed a median difference of 2 mm (range: 0.1 cm to 1.5 cm) where the radiological disease extent was overestimated and a median difference of 5 mm (range: 0.1 cm to 1.8 cm) when the radiological disease extent was underestimated [25]. In our study when MRI overestimated the extent of disease, the mean was 1.79 cm with a standard deviation of 1.56 cm.…”

“…In Han et al's series, restricted to only osteosarcoma cases, the maximum underestimation was 0.9 cm and the maximum over estimation was 3.4 cm [23]. Tao's study [25] excluded tumors involving thin bones like the radius, ulna and fibula, whereas we have included all tumors in 100 consecutive cases. In their study, estimation of tumor length was done on gross specimens whereas we had histopathology confirmation confirming the pathologic extent of disease as well.…”

Differentiation of microinfiltration and simple-edema areas in VX2 bone tumors by diffusion kurtosis imaging in animal experiments: a preliminary study

“…However, T1W imaging may underestimate the tumor size. A recent study (15) found that the median tumor length on resection specimens was approximately 4 mm greater than that on T1W imaging. Conversely, T2W, STIR, and T1W fat suppression contrast-enhanced sequences have also been reported to overestimate the tumor size (16,17).…”

3D-Printed Modular Endoprosthesis Reconstruction Following Total Calcanectomy in Calcaneal Malignancy

“…18,23 The use of MRI enables surgeons to accurately assess the extent of both intraosseous and extraosseous tumor involvement, which allows for an accurate preoperative evaluation and tumor resection. 15 At our institution, patients routinely had MRI imaging before chemotherapy and surgery to assess the response to neoadjuvant chemotherapy and determine the patient’s eligibility for limb-sparing surgery based on the MRI findings. Several factors are considered as contraindications to the use of the 3D-printed modular endoprosthesis, including tumor infiltration into major neurovascular structures, poor response to chemotherapy, involvement of adjacent bones, preexisting hindfoot and midfoot deformities, posterior tendon insufficiency, and vascular insufficiency preceding Achilles tendon pathology.…”