Gastrointestinal stromal tumors: a comprehensive radiological review

Cinematic Rendering of Gastrointestinal Stromal Tumours: A Review of Current Possibilities and Future Developments

Gastrointestinal stromal tumours (GISTs) are defined as CD117-positive primary, spindled or epithelioid, mesenchymal tumours of the gastrointestinal tract, omentum, or mesentery. While computed tomography (CT) is the recommended imaging modality for GISTs, overlap in imaging features between GISTs and other gastrointestinal tumours often make radiological diagnosis and subsequent selection of the optimal therapeutic approach challenging. Cinematic rendering is a novel CT post-processing technique that generates highly photorealistic anatomic images based on a unique lighting model. The global lighting model produces high degrees of surface detail and shadowing effects that generate depth in the final three-dimensional display. Early studies have shown that cinematic rendering produces high-quality images with enhanced detail by comparison with other three-dimensional visualization techniques. Cinematic rendering shows promise in improving the visualization of enhancement patterns and internal architecture of abdominal lesions, local tumour extension, and global disease burden, which may be helpful for lesion characterization and pretreatment planning. This article discusses and illustrates the application of cinematic rendering in the evaluation of GISTs and the unique benefit of using cinematic rendering in the workup of GIST with a specific emphasis on tumour characterization and preoperative planning.

Duodenal gastrointestinal stromal tumor presenting with life-threatening upper GI bleeding in a young patient: A case report and literature review

Key Clinical Message

Duodenal GISTs are rare and challenging tumors. Acute life-threatening upper GI bleeding is a possible presentation of duodenal GISTs. Surgery is the standard treatment for localized duodenal GISTs. Imatinib is an effective adjuvant therapy for duodenal GISTs.

Abstract

GIST is the most common mesenchymal neoplasm of the gastrointestinal tract, accounting for 1%-2% of gastrointestinal tumors. They originate from the interstitial cells of Cajal and are rare in patients younger than 30 years. The stomach is the most common site, followed by the small intestine and colon. GISTs are caused by a gain-of-function mutation in the proto-oncogene receptor tyrosine kinase, with activating mutations in KIT being the most common. Most GISTs are asymptomatic. Even if gastrointestinal bleeding is the most common complication life-threatening hemorrhage is extremely uncommon. We present a case of a 31-year-old male patient presented with massive active hematemesis and melena with hemorrhagic shock. The patient presented with massive hematemesis and melena of 1 h duration. Endoscopy showed pulsating active bleeding from the third part of the duodenum which was difficult to manage via endoscopy. Histopathologic evaluation showed spindle cell type GIST. Intraoperatively, there was a nodular mass with active bleeding on the third part of the duodenum. Duodenectomy with end-to-end anastomosis was done. Discharged with no postoperative complication and was put on imatinib. There are considerable challenges that arise in the diagnosis and treatment of duodenal gastrointestinal stromal tumors (GISTs) when they present with life-threatening upper gastrointestinal hemorrhage. In order to achieve the best possible outcomes for patients, it is crucial to have a comprehensive understanding of the clinical presentation, diagnostic methods, and treatment approaches.

Case report: detection of multiple sporadic gastrointestinal stromal tumors by dual-time 18 F-FDG PET/CT

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors affecting the gastrointestinal tract. Typically, GISTs are solitary; however, in rare cases, they may be multiple and appear in one or more organs. Multiple GISTs can appear in familial GISTs, children, or certain tumor syndromes such as neurofibromatosis type 1, Carney syndrome, and Carney-Stratakis syndrome. However, the diagnosis of primary multiple sporadic GISTs is often more difficult than that of these diseases. Herein, we report a case of multiple primary sporadic GISTs in a 64-year-old man, affecting the abdominal cavity and retroperitoneum, as identified through dual-time point positron emission tomography (PET) with 18F-labeled fluoro-2-deoxyglucose (18F-FDG) and computed tomography (18F-FDG PET/CT). Notably, the dual-time-point PET/CT revealed the migration of masses near the lower abdomen into the abdominal cavity. Furthermore, a significant increase in radioactive uptake of the mass 3 h after 18F-FDG injection compared with that 1 h after injection may be an important cue for its diagnosis.

Premalignant Lesions in the Kidney Transplant Candidate

End-stage kidney disease patients who are referred for transplant undergo an extensive evaluation process to ensure their health prior to transplant due in part to the shortage of available organs. Although management and surveillance guidelines exist for malignancies identified in the transplant and waitlist populations, less is written about the management of premalignant lesions in this population. This review covers the less common premalignant lesions (intraductal papillary mucinous neoplasm, gastrointestinal stromal tumor, thymoma, and pancreatic neuroendocrine tumor) that can be found in the transplant candidate population. High-level evidence for the management of these rarer premalignant lesions in the transplant population is lacking, and this review extrapolates evidence from the general population and should not be a substitute for a multidisciplinary discussion with medical and surgical oncologists.

Digestive bleeding due to jejunal stromal tumor: A train can hide another-A case report

Gastrointestinal mesenchymal tumors (GIST) are the most prevalent sarcoma tumors affecting the digestive tract. GIST originates from Cajal cells located within the digestive tract's wall. These cells play a crucial role in regulating digestive peristaltism as they are considered pacemaker cells. These tumors are especially located in the stomach (60%) but can also be seen in the small bowel (30%), in which jejunal stromal tumors are estimated to reach (40%). In this case report, we describe a jejunal GIST, which was initially discovered due to active bleeding, serving as the primary symptom, along with an underlying small loop intussusception. In our knowledge, GIST causing an intussusception is a rare entity in literature as well as GIST causing active bleeding. For that aim, we present a 36-year-old male patient, presented to our department with melena. An abdominal computed tomography scan was performed, revealing a small bowel intussusception associated with a 2 cm tumor. Despite the imprecise cause of the bleeding, due to the ongoing active hemorrhage, we decided to proceed with an emergency laparotomy, suspecting a tumorous origin of the bleeding. During the surgery, the tumor was located in the jejunum. The affected jejunal segment containing the tumor was resected, and an anastomosis was performed. Pathology examination confirmed a stromal tumor. The postoperative follow-up was uneventful.

Chronic abdominal pain revealing a gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GIST) are mesenchymal neoplasms most frequently seen in the stomach and small intestine, arising in the muscularis propria of the intestinal wall. Given its nonspecific clinical presentation, it can represent a diagnostic challenge, especially in abdominopelvic locations. Lesion evaluation of abdominopelvic tumors can be difficult and lead to misinterpretation in assessing their origin. We report the case of an 84-year-old woman with a voluminous small bowel GIST mimicking a uterine neoplasm.

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

Gastrointestinal stromal tumors (GISTs) are defined as mesenchymal tumors of the gastrointestinal tract that express positivity for CD117, which is a c-KIT proto-oncogene antigen. Expression of the c-KIT protein, a tyrosine kinase growth factor receptor, allows the distinction between GISTs and other mesenchymal tumors such as leiomyoma, leiomyosarcoma, schwannoma and neurofibroma. GISTs can develop anywhere in the gastrointestinal tract, as well as in the mesentery and omentum. Over the years, the management of GISTs has improved due to a better knowledge of their behaviors and risk or recurrence, the identification of specific mutations and the use of targeted therapies. This has resulted in a better prognosis for patients with GISTs. In parallel, imaging of GISTs has been revolutionized by tremendous progress in the field of detection, characterization, survival prediction and monitoring during therapy. Recently, a particular attention has been given to radiomics for the characterization of GISTs using analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence with the aim of better characterizing GISTs and providing a more precise assessment of tumor burden. This article sums up recent advances in computed tomography and magnetic resonance imaging of GISTs in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning.

Uncommon Association Between Gastrointestinal Stromal Tumors (GIST) and Pheochromocytoma With Abdominal Wall Relapse: Case Report and Literature Review

Gastrointestinal stromal tumors (GISTs) represent a rare form of gastrointestinal neoplasm. This report details a medical case involving a 44-year-old woman who underwent bilateral pheochromocytoma resection, GIST gastrectomy, and laparoscopic adrenalectomy with intestinal resection. Despite an initially positive response to oral imatinib, treatment was delayed due to economic constraints. This delay resulted in a critical event marked by abdominal GIST metastasis to the abdominal wall, subsequent rupture leading to hemoperitoneum, and emergency surgery. Following an adequate postsurgical recovery, she was successfully discharged prior to medication adjustments.

A mutation-based radiomics signature predicts response to imatinib in Gastrointestinal Stromal Tumors (GIST)

Objectives

To develop a mutation-based radiomics signature to predict response to imatinib in Gastrointestinal Stromal Tumors (GISTs).

Methods

Eighty-two patients with GIST were enrolled in this retrospective study, including 52 patients from one center that were used to develop the model, and 30 patients from a second center to validate it. Reference standard was the mutational status of tyrosine-protein kinase (KIT) and platelet-derived growth factor α (PDGFRA). Patients were dichotomized in imatinib sensitive (group 0 - mutation in KIT or PDGFRA, different from exon 18-D842V), and imatinib non-responsive (group 1 - PDGFRA exon 18-D842V mutation or absence of mutation in KIT/PDGFRA). Initially, 107 texture features were extracted from the tumor masks of baseline computed tomography scans. Different machine learning methods were then implemented to select the best combination of features for the development of the radiomics signature.

Results

The best performance was obtained with the 5 features selected by the ANOVA model and the Bayes classifier, using a threshold of 0.36. With this setting the radiomics signature had an accuracy and precision for sensitive patients of 82 % (95 % CI:60-95) and 90 % (95 % CI:73-97), respectively. Conversely, a precision of 80 % (95 % CI:34-97) was obtained in non-responsive patients using a threshold of 0.9. Indeed, with the latter setting 4 patients out of 5 were correctly predicted as non-responders.

Conclusions

The results are a first step towards using radiomics to improve the management of patients with GIST, especially when tumor tissue is unavailable for molecular analysis or when molecular profiling is inconclusive.

From FDG and beyond: the evolving potential of nuclear medicine

The radiopharmaceutical 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) has been dominantly used in positron emission tomography (PET) scans for over 20 years, and due to its vast utility its applications have expanded and are continuing to expand into oncology, neurology, cardiology, and infectious/inflammatory diseases. More recently, the addition of artificial intelligence (AI) has enhanced nuclear medicine diagnosis and imaging with FDG-PET, and new radiopharmaceuticals such as prostate-specific membrane antigen (PSMA) and fibroblast activation protein inhibitor (FAPI) have emerged. Nuclear medicine therapy using agents such as [177Lu]-dotatate surpasses conventional treatments in terms of efficacy and side effects. This article reviews recently established evidence of FDG and non-FDG drugs and anticipates the future trajectory of nuclear medicine.

Radiomics in gastrointestinal stromal tumours: an up-to-date review

Gastrointestinal stromal tumours are rare mesenchymal neoplasms originating from the Cajal cells and represent the most common sarcomas in the gastroenteric tract. Symptoms may be absent or non-specific, ranging from fatigue and weight loss to acute abdomen. Nowadays endoscopy, echoendoscopy, contrast-enhanced computed tomography, magnetic resonance imaging and positron emission tomography are the main methods for diagnosis. Because of their rarity, these neoplasms may not be included immediately in the differential diagnosis of a solitary abdominal mass. Radiomics is an emerging technique that can extract medical imaging information, not visible to the human eye, transforming it into quantitative data. The purpose of this review is to demonstrate how radiomics can improve the already known imaging techniques by providing useful tools for the diagnosis, treatment, and prognosis of these tumours.

N6-methyladenosine-modified microRNA-675 advances the development of gastrointestinal stromal tumors via inhibiting myosin phosphatase targeting protein 1

RNA N6-methyladenosine (m6A) modifications influence gastrointestinal stromal tumors (GISTs) development, but the detailed molecular mechanisms have not been fully studied. Here, microRNA-675 was found to be aberrantly elevated in cancerous tissues and cells of GISTs, compared to the corresponding normal counterparts, and GISTs patients with high-expressed microRNA-675 have worse outcomes. Additional experiments confirmed that silencing of microRNA-675 hindered cell division, mobility and tumorigenesis in vitro and in vivo, whereas triggered apoptotic cell death in GISTs cells. Furthermore, microRNA-675-ablation increased the expression levels of myosin phosphatase targeting protein 1 (MYPT1) to inactivate the tumor-initiating RhoA/NF2/YAP1 signal pathway, and downregulation of MYPT1 recovered the malignant phenotypes in microRNA-675-silenced GISTs cells. In addition, we evidenced that METTL3-mediated m6A modifications were essential for sustaining the stability of microRNA-675, and silencing of METTL3 restrained tumorigenesis of GISTs cells by regulating the microRNA-675/MYPT1 axis. To summarize, theMETTL3/m6A/microRNA-675/MYPT1 axis could be used as novel biomarkers for the diagnosis and treatment of GISTs.

Delayed Metastatic Cholangiocarcinoma to the Stomach With Imaging Characteristics Resembling Gastrointestinal Stromal Tumor: A Case Report and Review of the Literature

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare subtype of cholangiocarcinoma, and there has been an increasing incidence of ICC in Western countries in recent years. Surgical resection is the most effective treatment for ICC. However, overall outcomes are extremely poor given that most patients are diagnosed at an advanced stage, and postoperative ICC recurrence is still very high despite hepatic resection. We report a case of metastatic ICC to the stomach presenting after resection of the original tumor, with imaging characteristics highly resembling gastrointestinal stromal tumor (GIST) on imaging. Reported cases of metastatic ICC to the liver are sparse. Given that there is a significant difference in the survival rate between metastatic cholangiocarcinoma and other tumors arising from the gastrointestinal tract, including GISTs, it is important to delineate the differences via imaging features. We further discuss the imaging characteristics of intrahepatic ICC, comparing and contrasting it to other gastric tumors.

Imaging of Gastrointestinal Tract Ailments

Gastrointestinal (GI) disorders comprise a diverse range of conditions that can significantly reduce the quality of life and can even be life-threatening in serious cases. The development of accurate and rapid detection approaches is of essential importance for early diagnosis and timely management of GI diseases. This review mainly focuses on the imaging of several representative gastrointestinal ailments, such as inflammatory bowel disease, tumors, appendicitis, Meckel's diverticulum, and others. Various imaging modalities commonly used for the gastrointestinal tract, including magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT), and photoacoustic tomography (PAT) and multimodal imaging with mode overlap are summarized. These achievements in single and multimodal imaging provide useful guidance for improved diagnosis, staging, and treatment of the corresponding gastrointestinal diseases. The review evaluates the strengths and weaknesses of different imaging techniques and summarizes the development of imaging techniques used for diagnosing gastrointestinal ailments.

Radiomics signatures based on contrast-enhanced CT for preoperative prediction of the Ki-67 proliferation state in gastrointestinal stromal tumors

PURPOSE

This study aimed to evaluate the Ki-67 proliferation state in patients with gastrointestinal stromal tumors (GISTs) using radiomics prediction signatures based on contrast-enhanced computed tomography (CE-CT).

MATERIALS AND METHODS

This single-center, retrospective study involved 103 patients (48 men and 55 women, mean age 61.1 ± 10.6 years) who had pathologically confirmed GISTs after curative resection, including 63 with low Ki-67 proliferation level (Ki-67 labeling index ≤ 6%) and 40 with high Ki-67 proliferation level (Ki-67 labeling index > 6%). Radiomics features of the delineated lesions were preoperatively extracted from three-phase CE-CT images, including the arterial, venous, and delayed phases. The most relevant features were selected to construct the radiomics signatures using a logistic regression algorithm. Significant demographic characteristics and semantic features on CT were selected to develop a nomogram along with the optimal radiomics feature. We calculated the sensitivity, specificity, accuracy, F1 score, and area under the receiver operating characteristic (ROC) curve to evaluate the predictive performance of radiomics signatures.

RESULTS

Ten quantitative radiomics features (two first-order and eight texture features) were selected to construct radiomics signatures. The radiomics signature based on the three-phase CE-CT images showed better predictive performance than that based on the single-phase CE-CT images, with an area under the curve (AUC) of 0.83 (95% CI 0.73-0.92) and F1 score of 82% in the training dataset and an AUC of 0.80 (95% CI 0.63-0.95) and F1 score of 75% in the testing dataset. The nomogram showed good calibration.

CONCLUSION

Radiomics signatures using CE-CT images are generalizable and could be used in clinical practice to determine the proliferation state of Ki-67 in GISTs.

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

OBJECTIVES

To establish and validate a radiomics nomogram model for preoperative prediction of KIT exon 9 mutation status in patients with gastrointestinal stromal tumors (GISTs).

MATERIALS AND METHODS

Eighty-seven patients with pathologically confirmed GISTs were retrospectively enrolled in this study. Imaging and clinicopathological data were collected and randomly assigned to the training set (n = 60) and test set (n = 27) at a ratio of 7:3. Based on contrast-enhanced CT (CE-CT) arterial and venous phase images, the region of interest (ROI) of the tumors were manually drawn layer by layer, and the radiomics features were extracted. The intra-class correlation coefficient (ICC) was used to test the consistency between observers. Least absolute shrinkage and selection operator regression (LASSO) were used to further screen the features. The nomogram of integrated radiomics score (Rad-Score) and clinical risk factors (extra-gastric location and distant metastasis) was drawn on the basis of multivariate logistic regression. The area under the receiver operating characteristic (AUC) curve and decision curve analysis were used to evaluate the predictive efficiency of the nomogram, and the clinical benefits that the decision curve evaluation model may bring to patients.

RESULTS

The selected radiomics features (arterial phase and venous phase features) were significantly correlated with the KIT exon 9 mutation status of GISTs. The AUC, sensitivity, specificity, and accuracy in the radiomics model were 0.863, 85.7%, 80.4%, and 85.0% for the training group (95% confidence interval [CI]: 0.750-0.938), and 0.883, 88.9%, 83.3%, and 81.5% for the test group (95% CI: 0.701-0.974), respectively. The AUC, sensitivity, specificity, and accuracy in the nomogram model were 0.902 (95% confidence interval [CI]: 0.798-0.964), 85.7%, 86.9%, and 91.7% for the training group, and 0.907 (95% CI: 0.732-0.984), 77.8%, 94.4%, and 88.9% for the test group, respectively. The decision curve showed the clinical application value of the radiomic nomogram.

CONCLUSION

The radiomics nomogram model based on CE-CT can effectively predict the KIT exon 9 mutation status of GISTs and may be used for selective gene analysis in the future, which is of great significance for the accurate treatment of GISTs.