UMobileNetV2 model for semantic segmentation of gastrointestinal tract in MRI scans.

Gastrointestinal (GI) cancer is leading general tumour in the Gastrointestinal tract, which is fourth significant reason of tumour death in men and women. The common cure for GI cancer is radiation treatment, which contains directing a high-energy X-ray beam onto the tumor while avoiding healthy organs. To provide high dosages of X-rays, a system needs for accurately segmenting the GI tract organs. The study presents a UMobileNetV2 model for semantic segmentation of small and large intestine and stomach in MRI images of the GI tract. The model uses MobileNetV2 as an encoder in the contraction path and UNet layers as a decoder in the expansion path. The UW-Madison database, which contains MRI scans from 85 patients and 38,496 images, is used for evaluation. This automated technology has the capability to enhance the pace of cancer therapy by aiding the radio oncologist in the process of segmenting the organs of the GI tract. The UMobileNetV2 model is compared to three transfer learning models: Xception, ResNet 101, and NASNet mobile, which are used as encoders in UNet architecture. The model is analyzed using three distinct optimizers, i.e., Adam, RMS, and SGD. The UMobileNetV2 model with the combination of Adam optimizer outperforms all other transfer learning models. It obtains a dice coefficient of 0.8984, an IoU of 0.8697, and a validation loss of 0.1310, proving its ability to reliably segment the stomach and intestines in MRI images of gastrointestinal cancer patients.

Response Evaluation Criteria in Gastrointestinal and Abdominal Cancers: Which to Use and How to Measure.

As the management of gastrointestinal malignancy has evolved, tumor response assessment has expanded from size-based assessments to those that include tumor enhancement, in addition to functional data such as those derived from PET and diffusion-weighted imaging. Accurate interpretation of tumor response therefore requires knowledge of imaging modalities used in gastrointestinal malignancy, anticancer therapies, and tumor biology. Targeted therapies such as immunotherapy pose additional considerations due to unique imaging response patterns and drug toxicity; as a consequence, immunotherapy response criteria have been developed. Some gastrointestinal malignancies require assessment with tumor-specific criteria when assessing response, often to guide clinical management (such as watchful waiting in rectal cancer or suitability for surgery in pancreatic cancer). Moreover, anatomic measurements can underestimate therapeutic response when applied to molecular-targeted therapies or locoregional therapies in hypervascular malignancies such as hepatocellular carcinoma. In these cases, responding tumors may exhibit morphologic changes including cystic degeneration, necrosis, and hemorrhage, often without significant reduction in size. Awareness of pitfalls when interpreting gastrointestinal tumor response is required to correctly interpret response assessment imaging and guide appropriate oncologic management. Data-driven image analyses such as radiomics have been investigated in a variety of gastrointestinal tumors, such as identifying those more likely to respond to therapy or recur, with the aim of delivering precision medicine. Multimedia-enhanced radiology reports can facilitate communication of gastrointestinal tumor response by automatically embedding response categories, key data, and representative images. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Clustering-Guided Twin Contrastive Learning for Endomicroscopy Image Classification.

Learning better representations is essential in medical image analysis for computer-aided diagnosis. However, learning discriminative semantic features is a major challenge due to the lack of large-scale well-annotated datasets. Thus, how can we learn a well-structured categorizable embedding space in limited-scale and unlabeled datasets? In this paper, we proposed a novel clustering-guided twin-contrastive learning framework (CTCL) that learns the discriminative representations of probe-based confocal laser endomicroscopy (pCLE) images for gastrointestinal (GI) tumor classification. Compared with traditional contrastive learning, in which only two randomly augmented views of the same instance are considered, the proposed CTCL aligns more semantically related and class-consistent samples by clustering, which improved intra-class tightness and inter-class variability to produce more informative representations. Furthermore, based on the inherent properties of CLE (geometric invariance and intrinsic noise), we proposed to regard CLE images with any angle rotation and CLE images with different noises as the same instance, respectively, for increased variability and diversity of samples. By optimizing CTCL in an end-to-end expectation-maximization framework, comprehensive experimental results demonstrated that CTCL-based visual representations achieved competitive performance on each downstream task as well as more robustness and transferability compared with existing state-of-the-art SSL and supervised methods. Notably, CTCL achieved 75.60%/78.45% and 64.12%/77.37% top-1 accuracy on the linear evaluation protocol and few-shot classification downstream tasks, respectively, which outperformed the previous best results by 1.27%/1.63% and 0.5%/3%, respectively. The proposed method holds great potential to assist pathologists in achieving an automated, fast, and high-precision diagnosis of GI tumors and accurately determining different stages of tumor development based on CLE images.

Recent Progress of Image-Enhanced Endoscopy for Upper Gastrointestinal Neoplasia and Associated Lesions.

BACKGROUND: The main therapeutic modality of early upper gastrointestinal neoplasms has shifted from surgery to endoscopic therapy. The role of endoscopy has also expanded not only for more accurate diagnosis of neoplasms but also for the determination of extent and depth of neoplasms with a combination of multiple electronically modified images acquired with image-enhanced endoscopy (IEE) for assessing the feasibility of endoscopic treatment. SUMMARY: These IEE with or without magnifying endoscopy including narrow-band imaging, blue laser imaging, and linked color imaging (LCI) using narrow-band light have greatly changed the diagnosis for upper gastrointestinal neoplasms. These modalities produce high color contrast between cancer and surrounding mucosa at distant views and clear visualization of surface and vessels at close-up observations. LCI shows purple color of intestinal metaplasia (IM) distinct from other inflammatory gastric mucosae and facilitates the recognition of early gastric cancers often surrounded by IM. Recently, ultrathin endoscopy has provided high-resolution images similar to standard-caliber endoscopy. In addition, these advanced IEEs that integrate computer-assisted artificial intelligence systems are marked and will improve our diagnostic performance for neoplasia in the future. KEY MESSAGE: New IEE with sufficient brightness and color contrast has increasingly been used based on accumulated evidence for early and accurate detection of neoplastic lesions. We provide recent articles relevant to endoscopic diagnosis with IEE on esophageal, gastric, and duodenal neoplasms. Endoscopic equipment that integrates artificial intelligence support system is now being introduced into routine clinical use and is expected to enhance early detection of neoplastic lesions.

Fibroblast Activation Protein-Targeted PET/CT with 18F-Fibroblast Activation Protein Inhibitor-74 for Evaluation of Gastrointestinal Cancer: Comparison with 18F-FDG PET/CT.

Fibroblast activation protein is overexpressed in the stroma of several cancer types. 18F-fibroblast activation protein inhibitor (FAPI)-74 is a PET tracer with high selectivity for fibroblast activation protein and has shown high accumulation in human tumors in clinical studies. However, the use of 18F-FAPI-74 for PET imaging of gastrointestinal cancer has not been systematically investigated. Herein, we investigated the diagnostic accuracy of 18F-FAPI-74 (18F-LNC1005) PET/CT in gastric, liver, and pancreatic cancers and compared the results with those of 18F-FDG PET/CT. Methods: This prospective study analyzed patients with confirmed gastric, liver, or pancreatic malignancies who underwent concurrent 18F-FDG and 18F-FAPI-74 PET/CT between June 2022 and December 2022. PET/CT findings were confirmed by histopathology or radiographic follow-up. 18F-FDG and 18F-FAPI-74 uptake and tumor-to-background ratios were compared using the Wilcoxon signed-rank test. The McNemar test was used to compare the diagnostic accuracy of the 2 scans. Results: Our cohort consisted of 112 patients: 49 with gastric cancer, 39 with liver cancer, and 24 with pancreatic cancer. Among them, 69 patients underwent PET/CT for initial staging and 43 for recurrence detection. Regarding lesion-based diagnostic accuracy, 18F-FAPI-74 PET/CT showed higher sensitivity than did 18F-FDG in the detection of primary tumors (gastric cancer, 88% [22/25] vs. 60% [15/25], P = 0.016; liver cancer, 100% [22/22] vs. 82% [18/22], P = 0.125; pancreatic cancer, 100% [22/22] vs. 86% [19/22], P = 0.250), local recurrence (92% [23/25] vs. 56% [14/25]; P = 0.021), involved lymph nodes (71% [41/58] vs. 40% [23/58]; P < 0.001), and bone and visceral metastases (98% [350/358] vs. 47% [168/358]; P < 0.001). Compared with 18F-FDG, 18F-FAPI-74 PET/CT upstaged 17 patients' TNM staging among all treatment-naïve patients (17/69, 25%) and changed the clinical management of 4 patients (4/43, 9%) in whom recurrence or metastases were detected. Conclusion: 18F-FAPI-74 PET/CT is superior to 18F-FDG PET/CT in detecting primary tumors, local recurrence, lymph node involvement, and bone and visceral metastases in gastric, pancreatic, and liver cancers, with higher uptake in most primary and metastatic lesions.

Gastrointestinal stromal tumour: presenting as an ovarian cystadenoma.

A gastrointestinal stromal tumortumour (GIST) is an uncommon gastrointestinal neoplasm that can arise from any part of the gastrointestinal tract. They can rarely present as a pelvic mass, which might result in a gynaecological condition being misdiagnosed in a female patient. A woman in her early 70s presented with a huge pelvic mass. Abdomen-pelvis CT scan showed a significant cystic mass in the left-sided pelvis with a mass effect on adjacent structures, which suggested a possibility of an ovarian cystadenoma. Her CA-125 was normal. She underwent an exploratory laparotomy with pelvic mass excision. A diagnosis of a gastrointestinal stromal tumour (GIST) arising from the ileum was made on a histopathology study.

Diagnostic value of conventional endoscopic ultrasound for lymph node metastasis in upper gastrointestinal neoplasia: A meta-analysis.

BACKGROUND: Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer, both of which have high morbidity and mortality. Lymph node metastasis (LNM), as the most common metastasis mode of both diseases, is an important factor affecting tumor stage, treatment strategy and clinical prognosis. As a new fusion technology, endoscopic ultrasound (EUS) is becoming increasingly used in the diagnosis and treatment of digestive system diseases, but its use in detecting LNM in clinical practice remains limited. AIM: To evaluate the diagnostic value of conventional EUS for LNM in upper gastrointestinal neoplasia. METHODS: Using the search mode of "MeSH + Entry Terms" and according to the predetermined inclusion and exclusion criteria, we conducted a comprehensive search and screening of the PubMed, EMBASE and Cochrane Library databases from January 1, 2000 to October 1, 2022. Study data were extracted according to the predetermined data extraction form. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool, and the results of the quality assessment were presented using Review Manager 5.3.5 software. Finally, Stata14.0 software was used for a series of statistical analyses. RESULTS: A total of 22 studies were included in our study, including 2986 patients. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic score and diagnostic odds ratio of conventional EUS in the diagnosis of upper gastrointestinal neoplasia LNM were 0.62 [95% confidence interval (CI): 0.50-0.73], 0.80 (95%CI: 0.73-0.86), 3.15 (95%CI: 2.46-4.03), 0.47 (95%CI: 0.36-0.61), 1.90 (95%CI: 1.51-2.29) and 6.67 (95%CI: 4.52-9.84), respectively. The area under the summary receiver operating characteristic curve was 0.80 (95%CI: 0.76-0.83). Sensitivity analysis indicated that the results of the meta-analysis were stable. There was considerable heterogeneity among the included studies, and the threshold effect was an important source of heterogeneity. Univariable meta-regression and subgroup analysis showed that tumor type, sample size and EUS diagnostic criteria were significant sources of heterogeneity in specificity (P < 0.05). No significant publication bias was found. CONCLUSION: Conventional EUS has certain clinical value and can assist in the detection of LNM in upper gastrointestinal neoplasia, but it cannot be used as a confirmatory or exclusionary test.

Application of Nanoparticles in the Diagnosis of Gastrointestinal Diseases: A Complete Future Perspective.

The diagnosis of gastrointestinal (GI) diseases currently relies primarily on invasive procedures like digestive endoscopy. However, these procedures can cause discomfort, respiratory issues, and bacterial infections in patients, both during and after the examination. In recent years, nanomedicine has emerged as a promising field, providing significant advancements in diagnostic techniques. Nanoprobes, in particular, offer distinct advantages, such as high specificity and sensitivity in detecting GI diseases. Integration of nanoprobes with advanced imaging techniques, such as nuclear magnetic resonance, optical fluorescence imaging, tomography, and optical correlation tomography, has significantly enhanced the detection capabilities for GI tumors and inflammatory bowel disease (IBD). This synergy enables early diagnosis and precise staging of GI disorders. Among the nanoparticles investigated for clinical applications, superparamagnetic iron oxide, quantum dots, single carbon nanotubes, and nanocages have emerged as extensively studied and utilized agents. This review aimed to provide insights into the potential applications of nanoparticles in modern imaging techniques, with a specific focus on their role in facilitating early and specific diagnosis of a range of GI disorders, including IBD and colorectal cancer (CRC). Additionally, we discussed the challenges associated with the implementation of nanotechnology-based GI diagnostics and explored future prospects for translation in this promising field.

[18F] AlF­NOTA­FAPI­04 PET/CT as a promising tool for imaging fibroblast activation protein in gastrointestinal system cancers: a prospective investigation of comparative analysis with 18F-FDG.

PURPOSE: The radiopharmaceutical [18F]AlF-NOTA-FAPI-04 presents a promising alternative to 68 Ga-FAPI owing to its relatively longer half-life. This study aimed to evaluate the clinical usefulness of [18F]AlF-NOTA-FAPI-04 PET/CT for the diagnosis of primary and metastatic lesions in various types of gastrointestinal system cancers, compared with 18F-FDG PET/CT. METHODS: Patients diagnosed with gastrointestinal system malignancies were prospectively enrolled. All patients underwent both 18F-FDG and 18F-FAPI-04 PET/CT scans within one week, with 44 (73.3%) for cancer staging and 16 (26.7%) for tumor restaging. Diagnostic efficacy of the primary tumor, as well as the presence and number of lymph nodes and distant metastases, were assessed. Tumor uptake was quantified by the maximum standard uptake value (SUVmax). RESULTS: For detection of primary tumor, the diagnostic sensitivity of 18F-FDG PET/CT was 72.7%, while it was 97.7% for 18F-FAPI-04 PET/CT. Based on per-lymph node analysis, the sensitivity, specificity, and accuracy of 18F-FAPI-04 PET/CT in diagnosing metastatic lymph nodes were 91.89%, 92.00%, and 91.96%, respectively. These values were notably higher than those 18F-FDG PET/CT (79.72%, 81.33% and 80.80%, respectively). The 18F-FAPI-04 PET/CT surpassed 18F-FDG PET/CT in detecting suspected metastases in the brain (7 vs. 3), liver (39 vs. 20), bone (79 vs. 51), lung (11 vs. 4), and peritoneal carcinoma (48 vs. 22). Based on per-patient analysis, differential diagnostic accuracies (18F-FAPI-04 vs. 18F-FDG PET/CT) were observed in all patients (91.7% vs. 76.7%), the initial staging group (90.9% vs. 79.5%), and the re-staging group (93.8% vs. 68.7%). Additionally, 18F-FAPI-04 PET/CT revised final diagnosis in 31.7% of patients, contrasting with 18F-FDG PET/CT, and prompted changes in clinical management for 21.7% of the patients. CONCLUSION: 18F-FAPI-04 PET/CT outperforms 18F-FDG PET/CT in delineating the primary gastrointestinal tumors and detecting suspected metastatic lesions due to a higher target-to-background ratio (TBR). Moreover, 18F-FAPI-04 PET/CT could provide valuable guidance for tumor staging, thereby having a potential impact on patient management.

FAP-targeted PET imaging in gastrointestinal malignancies: a comprehensive review.

F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) plays a crucial role in tumour diagnosis, staging, and therapy response evaluation of various cancer types and has been a standard imaging modality used in clinical oncology practice for many years. However, it has certain limitations in evaluating some particular gastrointestinal cancer types due to low FDG-avidity or interphering physiological background activity. Fibroblast activation protein (FAP), a protein of the tumour microenvironment, is overexpressed in a wide range of cancers which makes it an attractive target for both tumour imaging and therapy. Recently, FAP-targeted radiopharmaceuticals are widely used in clinical research and achieved great results in tumour imaging. Considering the limitations of FDG PET/CT and the lack of physiological FAP-targeted tracer uptake in liver and intestinal loops, gastrointestinal cancers are among the most promising indications of FAP-targeted imaging. Herein, we present a comprehensive review of FAP-targeted imaging in gastrointestinal cancers in order to clarify the current and potential future role of this class of molecules in gastrointestinal oncology.

Radiomic applications in upper gastrointestinal cancer surgery.

INTRODUCTION: Cross-sectional imaging plays an integral role in the management of upper gastrointestinal (UGI) cancer, from initial diagnosis and staging to determining appropriate treatment strategies. Subjective imaging interpretation has known limitations. The field of radiomics has evolved to extract quantitative data from medical imaging and relate these to biological processes. The key concept behind radiomics is that the high-throughput analysis of quantitative imaging features can provide predictive or prognostic information, with the goal of providing individualised care. OBJECTIVE: Radiomic studies have shown promising utility in upper gastrointestinal oncology, highlighting a potential role in determining stage of disease and degree of tumour differentiation and predicting recurrence-free survival. This narrative review aims to provide an insight into the concepts underpinning radiomics, as well as its potential applications for guiding treatment and surgical decision-making in upper gastrointestinal malignancy. CONCLUSION: Outcomes from studies to date have been promising; however, further standardisation and collaboration are required. Large prospective studies with external validation and evaluation of radiomic integration into clinical pathways are needed. Future research should now focus on translating the promising utility of radiomics into meaningful patient outcomes.

Efficacy and Safety of Gastrointestinal Tumour Site Marking with da Vinci-Compatible Near-Infrared Fluorescent Clips: A Case Series.

BACKGROUND: The conventional near-infrared fluorescent clip (NIRFC) ZEOCLIP FS® has been used successfully in marking tumour sites during laparoscopic surgeries. However, this clip is difficult to observe with the Firefly imaging system equipped with the da Vinci® surgical system. We have been involved in the modification of ZEOCLIP FS® and development of da Vinci-compatible NIRFC. This is the first prospective single-centre case series study verifying the usefulness and safety of the da Vinci-compatible NIRFC. METHODS: Twenty-eight consecutive patients undergoing da Vinci®-assisted surgery for gastrointestinal cancer (16 gastric, 4 oesophageal, and 8 rectal cases) between May 2021 and May 2022 were enrolled. RESULTS: Tumour location was identified by the da Vinci-compatible NIRFCs in 21 of 28 (75%) patients, which involved 12 gastric (75%), 4 oesophageal (100%), and 5 rectal (62%) cancer cases. No adverse events were observed. CONCLUSION: Tumour site marking with da Vinci-compatible NIRFC was feasible in 28 patients enrolled in this study. Further studies are warranted to substantiate the safety and improve the recognition rate.

Integrating Functional Imaging and Molecular Profiling for Optimal Treatment Selection in Neuroendocrine Neoplasms (NEN).

PURPOSE OF REVIEW: Gastroenteropancreatic NEN (GEP-NEN) are group of malignancies with significant clinical, anatomical and molecular heterogeneity. High-grade GEP-NEN in particular present unique management challenges. RECENT FINDINGS: In the current era, multidisciplinary management with access to a combination of functional imaging and targeted molecular profiling can provide important disease characterisation, guide individualised management and improve patient outcome. Multiple treatment options are now available, and combination and novel therapies are being explored in clinical trials. Precision medicine is highly relevant for a heterogenous disease like NEN. The integration of dual-tracer functional PET/CT imaging, molecular histopathology and genomic data has the potential to be used to gain a more comprehensive understanding of an individual patient's disease biology for precision diagnosis, prognostication and optimal treatment allocation.

Gastrointestinal malignancies in pregnancy.

Gastrointestinal malignancies, though uncommon in pregnancy, present several unique challenges with regards to diagnosis, staging, and treatment. Imaging the pregnant patient with a suspected or confirmed GI malignancy requires modifications to the radiologic modality of choice and protocol in order to minimize harm to the fetus, ensure accuracy in diagnosis and staging and guide treatment decisions. In this review article, we discuss the imaging approach to the pregnant patient with GI cancer, including safe radiologic modalities and modifications to imaging protocols. We also review the most common GI cancers encountered in pregnancy, including colorectal, pancreatic, gastric, and small bowel tumors, with emphasis to imaging findings, staging, and treatment considerations.

CT features of gastrointestinal spindle cell, epithelial, and round cell tumors in 41 dogs.

There is sparse published information on computed tomographic (CT) characteristics of canine gastrointestinal tumors. The purposes of this multi-center, retrospective, descriptive study were to describe the CT features of histologically-confirmed canine gastrointestinal spindle cell, epithelial, and round cell tumors and, when available, describe the corresponding ultrasound findings. The inclusion criteria were as follows: availability of pre-and post-contrast CT study, and a histopathological diagnosis of the lesions. Recorded parameters were tumor size, location, gastrointestinal wall layers involvement, lesion's growth and enhancement patterns, tumor margination, presence of stenosis, mineralization, ulcerations, lymphadenopathy, or other lesions in the abdomen/thorax. When available, ultrasound images were evaluated. Forty-one dogs met the inclusion criteria and had the following histological diagnoses: 21/41 (51%) spindle cells (7 leiomyomas, 14 leiomyosarcomas/gastrointestinal stromal tumors (GISTs)), 13/41 (32%) epithelial (adenocarcinoma), and 7/41 (17%) round cell (lymphoma) tumors. The growth pattern was concentric, eccentric, and mixed in epithelial, spindle cell, and round cell tumors, respectively. Spindle cell tumors had the largest main volume and involved the outer gastrointestinal layer with an unaffected inner layer. Leiomyosarcomas/GISTs showed irregular margins compared to leiomyomas. Only lymphomas showed multifocal gastrointestinal involvement. Nine carcinomas and six spindle cell tumors caused partial stenosis with secondary sub-obstruction. Mineralizations were more frequent in spindle cell tumors (10/21) and absent in lymphomas. Lymphadenomegaly was widespread in lymphomas, regional in leiomyosarcomas-GISTs and adenocarcinomas, and absent in leiomyomas. The reported CT features may be useful in prioritizing the differential diagnosis between spindle cell, epithelial, and round cell tumors, similar to those reported on ultrasound.

Usefulness of [68Ga]FAPI-04 and [18F]FDG PET/CT for the detection of primary tumour and metastatic lesions in gastrointestinal carcinoma: a comparative study.

OBJECTIVE: To assess and compare the diagnostic performance of gallium-68-labelled fibroblast activation protein inhibitor ([68Ga]FAPI-04) and fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) in gastrointestinal cancer. METHODS: Fifty-one patients who underwent both [18F]FDG and [68Ga]FAPI-04 PET/CT for initial staging or restaging were enrolled. Histopathological findings, typical radiological appearances, and clinical imaging follow-up were used as the reference standard. The diagnostic performance of the two tracers was calculated and compared. The maximum standardised uptake value (SUVmax), mean SUV (SUVmean), tumour-to-mediastinal blood pool ratio (TBR), and tumour-to-liver ratio (TLR) of primary and metastatic lesions were measured and compared between two imaging modalities. RESULTS: In patient-based analysis, [68Ga]FAPI-04 showed much better diagnostic sensitivity than [18F]FDG in detecting primary tumour (94.44% [17/18] vs. 61.11% [11/18]), postoperative recurrence and metastases (95.65% [22/23] vs. 69.57% [16/23]), and peritoneal carcinomatosis (100% [28/28] vs. 60.71% [17/28]) (all p < 0.05). In lesion-based analysis, [68Ga]FAPI-04 showed higher sensitivity than [18F]FDG for detecting lymph node metastases. In peritoneal carcinomatosis, the median SUVmax (12.12 vs. 7.18) and SUVmean (6.84 vs. 4.11) with [68Ga]FAPI-04 were significantly higher than those with [18F]FDG (all p < 0.005). The TBR and TLR of [68Ga]FAPI-04 were significantly higher than those of [18F]FDG for detecting primary tumour, lymph node, liver, and peritoneal metastases (all p < 0.005). Therapeutic management changed in 13 patients according to [68Ga]FAPI-04 PET/CT compared with conventional imaging. CONCLUSIONS: [68Ga]FAPI-04 is superior to [18F]FDG PET/CT for detecting primary tumour, postoperative recurrence and metastasis, and peritoneal carcinomatosis in gastrointestinal cancer. KEY POINTS: • [68Ga]FAPI-04 PET/CT showed significantly higher sensitivity than [18F]FDG PET/CT in the detection of primary tumour and postoperative recurrence and metastasis in patients with gastrointestinal carcinoma. • [68Ga]FAPI-04 PET/CT had obvious advantages over [18F]FDG PET/CT in the detection of peritoneal carcinomatosis from gastrointestinal carcinoma with a much higher FAPI uptake value, TBR, and TLR. • Although the median SUVmax and SUVmean of [68Ga]FAPI-04 were similar to those of [18F]FDG for the primary tumour, lymph node metastases, and liver metastases in gastrointestinal carcinoma, the TBR and TLR of the SUVmax and SUVmean were significantly higher on [68Ga]FAPI-04 PET/CT, causing the lesions to be displayed more clearly.

Gastric gastrointestinal stromal tumor abscess.

A 70-year-old male with a large abscessed GIST is reported. Symptoms, laboratory results, diagnostic imaging and surgical field information are provided. It is a rare initial presentation of a GIST which we believe to be academically interesting.

The factors influencing the accuracy of pre-operative endoscopic ultrasonography assessment in endoscopic treatments for gastrointestinal tumors.

BACKGROUND: This retrospective study aimed to evaluate the factors influencing the accuracy of Endoscopic Ultrasonography (EUS) as a preoperative assessment for gastrointestinal tumors. METHODS: A total of 261 patients with 264 gastrointestinal tumors were enrolled in the study. The parameters of the gastrointestinal lesions examined under EUS and their pathology were recorded and analyzed. RESULTS: The accuracy of EUS for detecting intramucosal lesions and subepithelial lesions (SELs) were 83.6% and 91.4%, respectively. One hundred and ninety-four (73.5%) lesions originated from the mucous layer, as determined by pre-operation EUS examinations. The accuracy of EUS in predicting the correct T stage for intramucosal lesions in the gastric region, esophagus, and colorectum was 77%, 71.8%, and 84.6%, respectively. According to the Paris endoscopic classification, the distribution of macroscopic patterns was different between the EUS-pathology conformity and nonconformity groups (p = 0.018). In the nonconformity group, 48.6% of erosive lesions were classified as 0-IIc, 0-IIa + IIc, 0-IIc + IIa or 0-III macroscopic patterns compared with 26% patients in the conformity group (p = 0.025). Univariate analyses demonstrated that ulcerative lesions (OR = 7.516, 95% Confidence Interval [CI] 2.574-21.952, p < 0.001), location at the cardia of the stomach (OR = 3.619, 95%CI 1.076-12.168, p = 0.038), malignant tumor (OR = 2.920, 95%CI 1.339-6.368, p = 0.007) were significantly associated with EUS inaccuracy. Multivariate logistic regression analyses showed that ulcer was an independent risk factor associated with EUS inaccuracy, with odds ratios of 5.094 (95% CI: 1.641-15.807, p = 0.005). CONCLUSIONS: Our findings suggested that EUS is a reliable and easy-to-use diagnostic tool in decision-making regarding appropriate endoscopic treatment for gastrointestinal tumors. However, the diagnostic accuracy of EUS appeared questionable in the presence of ulceration.