Page 49 - TD-2-3

Tumor Discovery CE-SWI in desmoid fibromatosis assessment

improve the prediction of response/progression in desmoid tumors, enhancing the ability in discriminating between T2*-
hypointense-collagenized-mature and T1-shortened-enhancing immature components, respectively, in predominant
mature responsive and immature progressive tumors, respectively. RRR is relatively insensitive to volumetric tumor
changes before RECIST progression and tends to be better tuned with T2* signal and enhancement changes.

Keywords: Susceptibility weighted imaging; Desmoid fibromatosis; First order radiomics; Modified-Choi

1. Introduction CE-SWI can allow for the characterization of fibrous and
cellular components in desmoid fibromatosis.
Desmoid tumors are rare mesenchymal neoplasms
composed of a clonal proliferation of fibroblasts and This study aimed to determine the utility of the novel use
myofibroblasts with intracellular collagen and poorly of CE-SWI as a single sequence capable of simultaneously
defined margins [1-4] . These tumors are locally invasive soft- characterizing the Immature T2-hyperintense and
tissue lesions originating in connective tissue and express T1-shortening enhancing and the mature T2-hypointense
the intermediate filament vimentin but lack the expression collagenized components, using volumetric measurements
of epithelial markers such as E-cadherin . and first-order radiomic features compared against
[3]
conventional T2-based Response Evaluation Criteria in
Spontaneous regressions or prolonged stabilizations [20-22]
[2]
occur in about 66% of desmoid cases . Current guidelines Solid Tumors (RECIST) version 1.1 assessments for an
improved response assessment in desmoid fibromatosis.
recommend intervention on desmoid tumors only in
cases of progression, morbidity, or symptoms. There is This study provides initial evidence outlining the
no consensus on the best therapeutic management of novel use of CE-SWI as a single MRI sequence capable
[5]
these tumors . Surgery should be avoided because of the of providing insight regarding the underlying biological
difficulties of obtaining negative margins and the high risk changes of responsive and progressive desmoid tumors
of local recurrence . using 3D volumetric assessment, allowing improved
[2]
separation of T2-hypointense mature collagenized
In concordance with published evidence [2,6-8] , tumor from T2-hyperintense, T1-shortened-enhancing,
subjective clinical imaging evaluations often consider immature, and progressive tumor components.
progressive desmoid tumors to have a higher
proportion of T2-hyperintense and T1-shortened- 2. Methods
enhancing components, while responsive or mature
collagenized tumors demonstrate a higher proportion of An Institutional Review Board (IRB)-approved waiver of
T2-hypointense-non-enhancing components. The increase consent was obtained for this retrospective study, including
of T2-hypointense elements is typically considered a an initial pilot analysis of 10 single-lesion extremity desmoid
sign of positive response irrespective of tumor size [9-13] fibromatosis patients undergoing standard-of-care MRI
(Figure 1). In contrast, an increase in the T2-hyperintense examinations in our institution. Diagnostic biopsy and
and T1-shortened-enhancing components is often seen as pathologic confirmation of tumor histology were obtained
a sign of progression that can precede enlargement [10,12-14] . in all cases at diagnosis. The MRI scans included advanced
imaging sequences, including diffusion-weighted imaging/
Contrast-enhanced susceptibility-weighted imaging apparent diffusion coefficient [23,24] , perfusion-weighted imaging
(CE-SWI) is a 3D, high spatial resolution, velocity- with dynamic contrast enhancement (PWI/DCE) [25,26] , and
corrected gradient echo magnetic resonance imaging CE-SWI, performed between March 2021 and May 2023.
(MRI) technique that uses magnitude and filtered-phase
information, separately and in combination, to generate CE-SWI and T2-STIR data were collected from each
images [15-18] . The susceptibility effect from molecules patient across multiple time points in their treatment. A 3D
that have paramagnetic (deoxyhemoglobin, ferritin, and manual tumor segmentation was performed in 48 volumes
hemosiderin), diamagnetic (bone minerals, dystrophic of interest (VOIs) by an imaging-specialized research
calcifications, and oxyhemoglobin), or ferromagnetic assistant (M.A.C.) and an experienced skeletal radiologist
(iron, nickel, and cobalt) properties are demonstrated as (R.V.) using MIM commercial software (version 7.1.4,
areas of signal loss [15,17,18] . While the most common use MIM Software Inc., Cleveland, USA).
of CE-SWI is for identifying small amounts of calcium Data obtained from each VOI included maximum
and hemorrhage [18,19] , the soft tissue contrast offered by diameter, volume, and modified Choi (mChoi) measurements

Volume 2 Issue 3 (2023) 2 https://doi.org/10.36922/td.1414