PETCT Imaging as a Diagnostic Tool in Distinguishing Well-Differentiated versus Dedifferentiated Liposarcoma

Abstract EN

Distinguishing well-differentiated liposarcoma (WDLPS) from dedifferentiated liposarcoma (DDLPS) is essential given distinct treatment paradigms and chemosensitivity.

Percutaneous biopsy has a low sensitivity for detecting DDLPS.

We sought to identify the diagnostic utility of positron emission tomography/computed tomography (PET/CT) in identifying WDLPS versus DDLPS.

An independent radiologist reviewed PET/CT images to identify target lesions and determine the maximum standardized uptake value (SUVmax).

An independent pathologist review confirmed WDLPS or DDLPS histology.

A binary cutoff point of SUVmax was identified using a classification and regression trees (CART) algorithm.

We identified 20 patients with WDLPS or DDLPS with 26 PET/CTs performed for separate recurrences that were followed by surgical sampling.

Of the 26 records, 12 were DDLPS (46%) and 14 were WDLPS (54%).

Patients with DDLPS had significantly higher SUVmax than those with WDLPS (p value = 0.0035).

A SUVmax of 4 was identified as the cutoff point.

Using this cutoff, the sensitivity of SUVmax identifying a case as DDLPS was 83.3% (95% CI: 51.6%, 97.9%) and the specificity was 85.7% (95% CI: 57.2%, 98.2%).

PET/CT is a sensitive and specific diagnostic tool to identify the presence of dedifferentiation within the tumor.