Gastrointestinal stromal tumors: a comprehensive radiological review

Abstract

Gastrointestinal stromal tumors (GISTs) originating from the interstitial cells of Cajal in the muscularis propria are the most common mesenchymal tumor of the gastrointestinal tract. Multiple modalities, including computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography, ultrasonography, digital subtraction angiography, and endoscopy, have been performed to evaluate GISTs. CT is most frequently used for diagnosis, staging, surveillance, and response monitoring during molecularly targeted therapy in clinical practice. The diagnosis of GISTs is sometimes challenging because of the diverse imaging findings, such as anatomical location (esophagus, stomach, duodenum, small bowel, colorectum, appendix, and peritoneum), growth pattern, and enhancement pattern as well as the presence of necrosis, calcification, ulceration, early venous return, and metastasis. Imaging findings of GISTs treated with antineoplastic agents are quite different from those of other neoplasms (e.g. adenocarcinomas) because only subtle changes in size are seen even in responsive lesions. Furthermore, the recurrence pattern of GISTs is different from that of other neoplasms. This review discusses the advantages and disadvantages of each imaging modality, describes imaging findings obtained before and after treatment, presents a few cases of complicated GISTs, and discusses recent investigations performed using CT and MRI to predict histological risk grade, gene mutations, and patient outcomes.

Predictive Value of a Radiomics Nomogram Model Based on Contrast-Enhanced Computed Tomography for KIT Exon 9 Gene Mutation in Gastrointestinal Stromal Tumors

“…In previous studies, radiomics showed great potential for GISTs, which can effectively predict the malignant potential of GISTs, 28,29 mitotic index, 30 and Ki-67 expression index. 31,32 In addition, a preliminary study has been conducted on the use of radiomics for the classification and prediction of GISTs gene mutations.…”

CT and MRI of Gastrointestinal Stromal Tumours: New Trends and Perspectives

“…12 Several CT or MRI features are suggestive for the diagnosis of GIST; of these, extraluminal growth, marked enhancement on arterial phase images, early venous drainage and submucosal origin of the tumour, which is best depicted using CT-enteroclysis, are highly suggestive features. 2,[43][44][45] One study involving 124 patients (64 with GISTs and 60 with benign gastric polyp) who underwent CT examination, found that extraluminal growth (50%; 32/64), irregular margins (83%; 53/64) and tumour ulceration (28%; 18/64) were more frequently observed in gastric GISTs than in benign gastric polyps (10 [6/60]; 33% [20/ 60]; and 7% [4/60], respectively) (P < .001, <.001 and .002, respectively). 46 Similarly, GISTs showed greater degrees of enhancement during the arterial phase compared to benign gastric polyps.…”

“…Although they can develop anywhere in the gastrointestinal tract, the stomach is the most frequently affected organ (50-60% of GISTs) followed by the small bowel (20-30%) and the duodenum (10%). [1][2][3] GISTs most frequently arise from the muscularis propria of a given gastrointestinal organ but frequently involve the outer muscular layer, resulting in an exophytic growth. 3 However, GISTs can be submucosal, subserosal or intraluminal, thus explaining great variations in imaging presentation.…”

“…In general, CT and MRI supply information such as size, contour patterns, attenuation value or signal intensity, homogeneity and degree of enhancement. 2,4,10 Although these features may help predict high risk GIST, 12 they have limited capabilities to provide crucial data on gene mutation and response to therapy. 13 To overcome these limitations, the capabilities of radiomics have been evaluated in recent studies with encouraging results that have led to the development of radiomics models to predict risk of recurrence, gene mutation, prognosis, and response to targeted therapy.…”

“…8 Since the introduction of helical technology, computed tomography (CT) is the most used imaging technique for the assessment of GISTs. 2,3,9,10 CT provides crucial information that can suggest the diagnosis of GIST and be used for the follow-up of patients with GIST. 3,4,10 Magnetic resonance imaging (MRI) may contribute additional information in selected patients.…”