Diffusion‐weighted echo‐planar magnetic resonance imaging for the assessment of tumor cellularity in patients with soft‐tissue sarcomas

Abstract

Purpose To investigate the eligibility of diffusion‐weighted imaging (DWI) for the evaluation of tumor cellularity in patients with soft‐tissue sarcomas. Materials and Methods Thirty consecutive patients with a total of 31 histologically‐proven soft‐tissue sarcomas prospectively underwent magnetic resonance imaging (MRI) including DWI with echo‐planar imaging (EPI) technique immediately before open biopsy (N = 1) or tumor resection (N = 30). Fourteen patients had no previous anticancer treatment, 16 had received neoadjuvant therapy. Tumor cellularity as determined from histological sections was compared with minimum apparent diffusion coefficient (ADC). Results Tumor cellularity correlated well with minimum ADC in a linear fashion, with a Pearson correlation coefficient of –0.88 (95% confidence interval [CI]: –0.75 to –0.96). This relationship was not influenced by prior anticancer treatment. There was only a tendency toward lower ADC in tumor with higher grading but no significant dependency (P = 0.08). Conclusion DWI has proven useful for the assessment of tumor cellularity in soft‐tissue sarcomas. In result, DWI may be used as a powerful noninvasive tool to monitor responses of cytotoxic treatment as reflected by changes in tumor cellularity. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.

ADC measurements in the evaluation of lymph nodes in patients with non-Hodgkin lymphoma: feasibility study

“…The ADC may provide a reflection of anatomic and functional cellular characteristics. For example, the ADC has shown to be inversely correlated to the tissue cellularity and the integrity of cell membranes [23][24][25]. As such, it may aid in the characterization of lesions [9], including the assessment of lymph nodes in patients with NHL.…”

“…On the other hand, diffuse large B-cell lymphomas (which are the most common of the high-grade lymphomas) consist of larger neoplastic cells [8], which may correspond to a relatively lower cellular density. Since lesions with a higher cellularity are known to have a lower diffusivity than lesions with a lower cellularity [23][24][25], ADC measurements may also be of utility in predicting malignancy grade in patients with lymphoma.…”

Musculoskeletal Tumors: How to Use Anatomic, Functional, and Metabolic MR Techniques

“…DW imaging has also been used for characterizing changes in the surgical bed in patients examined for evaluation of the possibility of recurrent tumor (23). Furthermore, DW imaging is well suited to the study of a sarcoma after neoadjuvant therapy to determine whether treatment-related necrosis has occurred in a tumor (19,22,(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45). Where cytotoxic edema develops (eg, in areas of treatment-related necrosis with changes to the dependent sodium-potassium pumps across the cell membrane), there will be increased water mobility, as compared with areas where tumor cellularity is maintained (eg, nonresponsive tumors) (46).…”

A 12-year-old Girl With an Extraosseous Chondrosarcoma

“…1), their appearance on DWI has not yet been described [2]. Most "soft-tissue" (mesenchymal-origin) sarcomas have consistently demonstrated lower ADC values (represented as bright signal on DWI) with an inverse correlation between tumor cellularity and ADC values [7].…”

“…"high diffusivity," based on measurements of osseous chondrosarcomas [7]. Although the DWI characteristics of extraosseous chondrosarcomas have not yet been described, the appearance of extraosseous and osseous chondrosarcomas is quite similar on other MR sequences, and thus their DWI characteristics of high diffusivity (high ADC values) should be similar [8].…”