"Four-Step Procedure" of laparoscopic exploration for gastric cancer in West China Hospital: a retrospective observational analysis from a high-volume institution in China

Multimodal Artificial Intelligence-Based Virtual Biopsy for Diagnosing Abdominal Lavage Cytology-Positive Gastric Cancer

Gastric cancer with peritoneal dissemination remains a significant clinical challenge due to its poor prognosis and difficulty in early detection. This study introduces a multimodal artificial intelligence-based risk stratification assessment (RSA) model, integrating radiomic and clinical data to predict peritoneal lavage cytology-positive (GC-CY1) in gastric cancer patients. The RSA model is trained and validated across retrospective, external, and prospective cohorts. In the training cohort, the RSA model achieved an area under the curve (AUC) of 0.866, outperforming traditional clinical and radiomic feature models. External validation cohorts confirmed its robustness, with AUC values of 0.883 and 0.823 for predicting peritoneal metastasis and recurrence, respectively. In a prospective validation involving 152 patients, the model maintained superior predictive performance (AUC = 0.835). The RSA model also demonstrated significant clinical benefits by effectively identifying high-risk patients likely to benefit from specific treatments, such as paclitaxel-based conversion therapy. These findings suggest that the RSA model offers a reliable, non-invasive diagnostic tool for gastric cancer, capable of improving early detection and treatment outcomes. Further prospective studies are warranted to explore its full clinical potential.

Artificial intelligence assisted real-time recognition of intra-abdominal metastasis during laparoscopic gastric cancer surgery

Laparoscopic exploration (LE) is crucial for diagnosing intra-abdominal metastasis (IAM) in advanced gastric cancer (GC). However, overlooking single, tiny, and occult IAM lesions during LE can severely affect the treatment and prognosis due to surgeons' visual misinterpretations. To address this, we developed the artificial intelligence laparoscopic exploration system (AiLES) to recognize IAM lesions with various metastatic extents and locations. The AiLES was developed based on a dataset consisting of 5111 frames from 100 videos, using 4130 frames for model development and 981 frames for evaluation. The AiLES achieved a Dice score of 0.76 and a recognition speed of 11 frames per second, demonstrating robust performance in different metastatic extents (0.74-0.76) and locations (0.63-0.90). Furthermore, AiLES performed comparably to novice surgeons in IAM recognition and excelled in recognizing tiny and occult lesions. Our results demonstrate that the implementation of AiLES could enhance accurate tumor staging and assist individualized treatment decisions.

68Ga-FAPI-04 positron emission tomography/CT and laparoscopy for the diagnosis of occult peritoneal metastasis in newly diagnosed locally advanced gastric cancer: study protocol of a single-centre prospective cohort study

INTRODUCTION

Accurate baseline clinical staging is critical to inform treatment decision-making for patients with gastric cancers. Peritoneal metastasis (PM) is the most common form of metastasis in gastric cancer and mainly diagnosed by diagnostic laparoscopy and peritoneal lavage evaluation. However, diagnostic laparoscopy is invasive and less cost-effective. It is urgent to develop a safe, fast and non-invasive functional imaging method to verify the peritoneal metastasis of gastric cancer. The aim of our study was to evaluate the proportion of patients in whom 68Ga-FAPI-04 positron emission tomography/CT (PET/CT) led to a change in treatment strategy and to assess the diagnostic accuracy of 68Ga-FAPI-04 PET/CT for the detection of occult peritoneal metastasis compared with laparoscopic exploration.

METHODS AND ANALYSIS

In this single-centre, prospective diagnostic test accuracy study, a total of 48 patients with locally advanced gastric or gastro-oesophageal junction adenocarcinoma (cT4a-b, N0-3, M0, based on CT images) who are considering radical tumour surgery will be recruited. All participants will undergo 68Ga-FAPI-04 PET/CT before the initiation of laparoscopic exploration. The primary outcome is the proportion of patients with occult peritoneal metastatic lesions detected by 68Ga-FAPI-04 PET/CT, leading to a change in therapy strategy. The secondary outcomes include the diagnostic performance of 68Ga-FAPI-04 PET/CT for occult peritoneal metastasis, including sensitivity, specificity, accuracy, positive predictive value and negative predictive value.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of West China Hospital, Sichuan University (2022-1484). Study results will be presented at public and scientific conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2300067591.

Case Report: Laparoscopy-assisted resection for intra-abdominal gossypiboma masquerading as a jejunal tumor (with video)

INTRODUCTION

Intra-abdominal gossypiboma, a cotton-based retained foreign body after an abdominal surgery, is associated with various clinical manifestations and complications. Its infrequent occurrence and unpredictability make its early diagnosis particularly challenging. We herein present an atypical case of intra-abdominal gossypiboma mistaken for a jejunal tumor.

CASE PRESENTATION

A 33-year-old female presented to the emergency room with an acute episode of progressive abdominal pain and distention, nausea, and vomiting for 20 hours. She had undergone an urgent cesarean section due to fetal tachycardia seven years prior. The initial diagnosis of small bowel obstruction (SBO) due to a jejunal tumor was established by computed tomography. Subsequent to successful medical management of the SBO, a laparoscopy-assisted resection of the mass and the adherent jejunal segment was conducted, culminating in a primary side-to-side jejunojejunostomy. Examination of the excised tissue revealed an approximately spherical fibrous mass, 6 × 6 × 5 cm in dimension, embedded in the jejunal wall, housing a 20 × 20-cm gauze. Postoperative recovery and routine follow-up ensued without complications.

CONCLUSION

In light of this case, the need for clinicians to maintain an elevated awareness and suspicion of gossypiboma should be accentuated when evaluating an intra-abdominal mass, especially in patients with a prior history of high-risk laparotomy. Laparoscopic surgery stands out as a technically proficient and minimally invasive strategy for diagnosing and treating intra-abdominal gossypiboma. Besides, it is imperative to emphasize the importance of meticulous surgical procedures and postoperative protocols to prevent such oversights, reaffirming the need for consistent intraoperative counts and checks of surgical items.

Techniques of staging laparoscopy and peritoneal fluid assessment in gastric cancer: a systematic review

BACKGROUND

Staging laparoscopy for gastric cancer is recommended to assess the tumor's locoregional extension and exclude peritoneal disease. As there is no consensus on optimizing the procedure's diagnostic accuracy, we aimed to systematically review the literature on operative techniques, followed by peritoneal lavage fluid assessment in gastric cancer patients. Specifically, we sought to indicate the most common characteristics of the procedure and cytological evaluation.

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol for this systematic review was registered on PROSPERO database (CRD: 42022306746). On September 2022, a search was carried out using Embase, Medline ALL, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection.

RESULTS

The search identified 1632 studies on staging laparoscopy and 2190 studies on peritoneal fluid assessment. Some 212 studies were included. Open Hasson was the method of choice in accessing the peritoneal cavity in 65% of the studies, followed by establishing a pneumoperitoneum at 10-12 mmHg in 52% of reports. Most frequently, the patient was positioned supine (70%), while a 30° scope and three ports were used to assess the peritoneal cavity clockwise (72%, 77%, and 85%, respectively). Right and left upper abdomen quadrants were the predominant area of laparoscopic exploration (both 65%), followed by the primary tumor region (54%), liver and pelvis (both 30%), and small bowel and spleen (19% and 17%, respectively). Regions of peritoneal lavage and aspiration were limited to the pelvis (50%), followed by right and left upper abdomen quadrants (37.5% and 50%, respectively). No studies compared different methods of operative techniques or analysis of ascites/fluid.

CONCLUSIONS

This study indicates a high heterogeneity in the technique of staging laparoscopy and peritoneal fluid assessment in gastric cancer patients. Further research and initiatives to reach a consensus on the standardization of the procedure are warranted.

The Role of Staging Laparoscopy for Gastric Cancer Patients: Current Evidence and Future Perspectives

A significant proportion of patients diagnosed with gastric cancer is discovered with peritoneal metastases at laparotomy. Despite the continuous improvement in the performance of radiological imaging, the preoperative recognition of such an advanced disease is still challenging during the diagnostic work-up, since the sensitivity of CT scans to peritoneal carcinomatosis is not always adequate. Staging laparoscopy offers the chance to significantly increase the rate of promptly diagnosed peritoneal metastases, thus reducing the number of unnecessary laparotomies and modifying the initial treatment strategy of gastric cancer. The aim of this review was to provide a comprehensive summary of the current literature regarding the role of staging laparoscopy in the management of gastric cancer. Indications, techniques, accuracy, advantages, and limitations of staging laparoscopy and peritoneal cytology were discussed. Furthermore, a focus on current evidence regarding the application of artificial intelligence and image-guided surgery in staging laparoscopy was included in order to provide a picture of the future perspectives of this technique and its integration with modern tools in the preoperative management of gastric cancer.

Situación actual de la laparoscopía de estadificación en pacientes con cáncer gástrico en Colombia: ¿Cómo lo estamos haciendo?

Introducción. La laparoscopía de estadificación permite identificar con gran precisión el compromiso locorregional avanzado y metastásico a peritoneo en los pacientes con cáncer gástrico. Las guías internacionales aún difieren en las indicaciones para incluir este procedimiento como parte del proceso de estadificación. Métodos. Se diseñó una encuesta dirigida a cirujanos residentes en Colombia, sobre el uso de la laparoscopía de estadificación en los pacientes con cáncer gástrico. Se analizaron los resultados y con base en la evidencia disponible se proponen algunas pautas en las indicaciones y técnica del procedimiento. Resultados. Respondieron la encuesta 74 cirujanos; el 43,8 % considera que el objetivo de la laparoscopía de estadificación es descartar la carcinomatosis peritoneal. El 54,1 % realiza el procedimiento en estadios tempranos, sin embargo, el 48,6 % considera realizarla solo en pacientes con sospecha de carcinomatosis por imágenes. Las áreas evaluadas con mayor frecuencia por los cirujanos (más del 85 %) son la superficie hepática, las cúpulas diafragmáticas, los recesos parietocólicos y la pelvis. Las zonas evaluadas en menor frecuencia son la válvula ileocecal (40,5 %) y el ligamento de Treitz (39 %). El 33 % de los cirujanos no toma rutinariamente citología peritoneal. Conclusión. Este trabajo muestra la tendencia de los cirujanos en el uso de la laparoscopía de estadificación en pacientes con cáncer gástrico. A pesar de encontrar resultados muy positivos en relación con las indicaciones y técnica del procedimiento, es necesario analizar la evidencia disponible para su uso según cada escenario y mejorar la sistematización del procedimiento.

Molecular Determinants of Peritoneal Dissemination in Gastric Adenocarcinoma

BACKGROUND

Peritoneal dissemination represents a poor prognostic indicator in gastric cancer. Despite a comprehensive molecular characterization of this disease, no peritoneal dissemination-specific signature has been identified, limiting the tailoring of the surgical and oncological treatments. In this review, we outline the available literature focusing on the role of the different molecular pathways involved in the acquisition of peritoneal metastatic dissemination.

SUMMARY

According to our results, several molecular determinants are associated with peritoneal carcinomatosis and are involved in several cellular and molecular carcinogenetic processes. However, a comprehensive understanding of the complex molecular landscape of gastric carcinosis is still lacking.

KEY MESSAGES

More efforts should be made toward the integration of molecular and histologic data to perform a risk prediction assessment of peritoneal dissemination based on molecular profiling and histological evaluation.

The Safety and Feasibility of Laparoscopic Gastrectomy after Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer

Background

Neoadjuvant chemotherapy is incrementally applied to remedy locally advanced gastric cancer. However, NACT also enhances the difficulty of laparoscopic lymph node dissection. The objective of our study was to evaluate the safety and feasibility of laparoscopic gastrectomy for locally advanced gastric cancer after neoadjuvant chemotherapy.

Methods

From July 2017 to December 2019, 153 patients who received neoadjuvant chemotherapy and underwent the subsequent surgical procedure were retrospectively enrolled and analyzed in the Gastrointestinal Surgery Department of West China Hospital. According to surgical methods, all the patients were sectionalized into two groups: laparoscopic assistant gastrectomy (LAG, 77 patients) and traditional open gastrectomy (OG, 76 patients). The demographic parameters, preoperative, surgical, pathological, and neoadjuvant chemotherapy features were compared between the two groups.

Results

A total of 153 patients accepted neoadjuvant chemotherapy and surgical resection in our study. There was no statistically significant difference in demographic parameters and preoperative and neoadjuvant chemotherapy characteristics between the two groups. The LAG group illustrated less intraoperative blood loss (91.1 ± 53.1 ml vs. 125.7 ± 116.9 ml, p=0.010) and shorter postoperative hospital stays (7.9 ± 2.1 days vs. 125.7 ± 116.9 days, p=0.009), when compared to the OG group. Moreover, there was no disparity with respect to operative duration, number of harvested lymph nodes, and postoperative complication rates between the two groups. When considering the Clavien-Dindo classification, no statistically significant difference was indicated in all stratifications with regard to postoperative complications.

Conclusion

Laparoscopic gastrectomy for locally advanced gastric cancer after neoadjuvant chemotherapy is safe and feasible without increasing postoperative adverse events.

Clinical Significance of Peritoneal Fluid Examination for Free Cancer Cells in Patients Qualified for Surgery for Gastric Cancer

Background: Peritoneal lavage cytology in patients with gastric cancer may correlate with an unfavorable prognosis. This study evaluated the presence of free cancer cells in the peritoneal lavage of a population of patients with gastric cancer and its correlation with the outcome of surgical treatment.

Methods: One hundred patients diagnosed with gastric or gastrointestinal junction adenocarcinoma underwent surgery. In all patients, a cytological and immunohistochemical analysis of peritoneal lavage was performed. Based on the presence of free cancer cells (fcc) at the cytological and immunohistochemical examination of peritoneal lavage, patients undergoing surgery for gastric cancer were divided into two groups: fcc (+) and fcc (–).

Results: A total of 100 patients, 37 women, and 63 men with a median age of 65 years were included in the study. In the entire study group, 16 (16%) patients were positive for the presence of free cancer cells (fcc +) at peritoneal lavage examination. However, in the group of patients who underwent gastrectomy, fcc (+) was found in 10 out of 77 (13%) patients. The presence of cancer cells in peritoneal lavage was a strong predictive factor in an unfavorable outcome after surgery, and 1-year and 2-year patient survival was 34 and 0% in fcc (+) patients and 79 and 59% in fcc (–), respectively. Moreover, the presence of free cancer cells was associated with a five-fold increased risk of death within 2 years after surgery. When analyzing the group of patients undergoing R0/R1 surgery, this difference was even more significant (p < 0.0001).

Conclusions: The presence of free cancer cells in peritoneal lavage may significantly affect the outcome of patients with gastric cancer. Radical surgery in patients with free cancer cells in the peritoneal lavage did not result in a survival advantage. Identification of free cancer cells could help for a better stratification of gastric cancer patients, identifying those patients who could better benefit from a radical surgical treatment, finally improving long-term survival.

Deep Convolutional Neural Network Based on Computed Tomography Images for the Preoperative Diagnosis of Occult Peritoneal Metastasis in Advanced Gastric Cancer

We aimed to develop a deep convolutional neural network (DCNN) model based on computed tomography (CT) images for the preoperative diagnosis of occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC). A total of 544 patients with AGC were retrospectively enrolled. Seventy-nine patients were confirmed with OPM during surgery or laparoscopy. CT images collected during the initial visit were randomly split into a training cohort and a testing cohort for DCNN model development and performance evaluation, respectively. A conventional clinical model using multivariable logistic regression was also developed to estimate the pretest probability of OPM in patients with gastric cancer. The DCNN model showed an AUC of 0.900 (95% CI: 0.851-0.953), outperforming the conventional clinical model (AUC = 0.670, 95% CI: 0.615-0.739; p < 0.001). The proposed DCNN model demonstrated the diagnostic detection of occult PM, with a sensitivity of 81.0% and specificity of 87.5% using the cutoff value according to the Youden index. Our study shows that the proposed deep learning algorithm, developed with CT images, may be used as an effective tool to preoperatively diagnose OPM in AGC.