Laparoscopic narrow band imaging for detection of occult cancer metastases: a randomized feasibility trial

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.

New diagnostic strategy using narrow-band imaging (NBI) during laparoscopic surgery for patients with colorectal cancer

BACKGROUND

Accurate tumor stage diagnosis during laparoscopic surgery remains difficult. We clarify the impact of new diagnostic strategy using narrow-band imaging (NBI) during laparoscopic surgery for colorectal cancer compared with other strategies.

METHODS

We defined angiogenesis (Ag) and fibrosis (Fib) grades using NBI laparoscopy (lap-NBI), and assessed the clinicopathological features associated with these grades for 67 patients with colorectal cancer who underwent surgery. We assessed vessel density and gray scale with computer software.

RESULTS

NBI-Ag-grade and NBI-Fib-grade of the serosal surface of cancer lesions and peritoneal nodules correlated with vessel density and gray scale of those assessed by Image J computer software. NBI-Fib-grades of liver nodules also correlated with gray scale. NBI-Ag- grade and Fib-grade of the serosal surface of cancer lesions correlated with pathological depth of invasion. These NBI grades of pathological metastatic peritoneal nodules were higher than those of pathologically benign peritoneal nodules. NBI- Fib grades of pathological metastatic liver nodules were higher than those of pathologically benign liver nodules. In multivariate analysis, lap-NBI was associated with different diagnosis for T3, T4 and non-T3, and non-T4. Moreover, lap-NBI was associated with different diagnosis for T4 and non-T4. Predictive value for T4 by lap-NBI showed high sensitivity (85%) specificity (87%), positive predictive value (74%), negative predictive value (93%), and overall accuracy (87%). Sensitivity and overall accuracy of lap-NBI was superior to that of other diagnostic modalities.

CONCLUSION

We clarified the usefulness of the new diagnostic strategy using lap-NBI during laparoscopic surgery for colorectal cancer in comparison with other strategies.

Improving tissue characterization, differentiation and diagnosis in gynecology with the narrow-band imaging technique: A systematic review

Narrow-band imaging (NBI), an on-demand, real-time endoscopic imaging technique, was developed to enhance visualization of the mucosal vascular network and surface texture. The present article provides a systematic review of studies that assessed the use of NBI in gynecological endoscopy. The following electronic databases were searched: PubMed (1950-2020), Google Scholar (2004-2020) and Cochrane Library (2010-2020). In the initial search, 3,836 entries were identified, of which 31 were finally included in the systematic review. Of the selected studies, 10 (32%) were case reports, 19 (61.2%) were prospective studies and 2 (6.4%) were randomized controlled trials with control groups. The selected studies reported on the use of NBI in hysteroscopy, laparoscopy and colposcopy. It was revealed that NBI utilization in hysteroscopy increased the accuracy, sensitivity and specificity in detecting malignant and premalignant lesions. NBI improved the specificity and sensitivity in the detection of endometriotic lesions and cervical lesions. Conventional white light endoscopy in gynecology may be significantly improved by the use of NBI. Further studies with larger cohorts and improved design are required to achieve more reliable results. It is of special interest that utilization of this method requires apparatus which is expensive; concerns are the long training and experience of staff required and the long learning curve.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Use of imaging as staging and surgical planning for pancreatic surgery

Importance

In the past few decades, there has been rapid advancements in imaging technologies that have become irreplaceable in the pre-operative assessment of patients with pancreatic tumors. Modern imaging modalities, including computed tomography (CT) and endoscopic ultrasound (EUS), can provide critical information of the absence or presence of metastatic disease in pancreatic cancer, as well as details on the local extent and resectability, allowing for the selection of stage appropriate treatments and pre-operatively determined surgical approach.

Objective

The aim of this review is to discuss staging, resectability, and imaging for patients with pancreatic tumors.

Evidence Review

A literature review was performed of articles relevant to the topics of staging, resectability, and imaging of pancreatic tumors. Imaging modalities included CT, EUS, magnetic resonance imaging (MRI), positron emission tomography (PET), antibody-based and narrow band imaging.

Findings

CT pancreas protocol combined with EUS serve as the primary modalities in diagnosis, staging, and surgical planning in patients with pancreatic tumors. MRI is an alternative to CT with near equivalent utility in the pre-operative setting. In some circumstances, PET-CT may be a cost-effective initial study to detect distant disease.

Conclusions and Relevance

Current imaging technologies play a critical role in the evaluation of patients with pancreatic tumors. Advances in the past 3 decades in imaging technologies have revolutionized the process of assessment of stage and resectability in patients with pancreatic tumors. Future imaging technologies will address current limitation in the evaluation of occult metastatic disease.

Can We Accurately Identify Peritoneal Metastases Based on Their Appearance? An Assessment of the Current Practice of Intraoperative Gastrointestinal Cancer Staging

BACKGROUND

Peritoneal lesions are common findings during operative abdominal cancer staging. The decision to perform biopsy is made subjectively by the surgeon, a practice the authors hypothesized to be imprecise. This study aimed to describe optical characteristics differentiating benign peritoneal lesions from peritoneal metastases.

METHODS

The study evaluated laparoscopic images of 87 consecutive peritoneal lesions biopsied during staging laparoscopies for gastrointestinal malignancies from 2014 to 2017. A blinded survey assessing these lesions was completed by 10 oncologic surgeons. Three senior investigators categorized optical features of the lesions. Computer-aided digital image processing and machine learning was used to classify the lesions.

RESULTS

Of the 87 lesions, 28 (32%) were metastases. On expert survey, surgeons on the average misidentified 36 ± 19% of metastases. Multivariate analysis identified degree of nodularity, border transition, and degree of transparency as independent predictors of metastases (each p < 0.03), with an area under the receiver operating characteristics curve (AUC) of 0.82 (95% confidence interval [CI], 0.72-0.91). Image processing demonstrated no difference using image color segmentation, but showed a difference in gradient magnitude between benign and metastatic lesions (AUC, 0.66; 95% CI 0.54-0.78; p = 0.02). Machine learning using a neural network with a tenfold cross-validation obtained an AUC of only 0.47.

CONCLUSIONS

To date, neither experienced oncologic surgeons nor computerized image analysis can differentiate peritoneal metastases from benign peritoneal lesions with an accuracy that is clinically acceptable. Although certain features correlate with the presence of metastases, a substantial overlap in optical appearance exists between benign and metastatic peritoneal lesions. Therefore, this study suggested the need to perform biopsy for all peritoneal lesions during operative staging, or at least to lower the threshold significantly.

Narrow-Band Imaging Improves Detection of Colorectal Peritoneal Metastases: A Clinical Study Comparing Advanced Imaging Techniques

Background

Colorectal peritoneal metastases (PM) are often diagnosed in an advanced disease stage. Cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival of patients with colorectal PM, although most benefit is seen in patients with limited peritoneal disease. Advanced imaging techniques might improve the detection of PM, potentially leading to earlier diagnosis and improved cytoreduction. This prospective clinical trial compared three advanced techniques with conventional white-light imaging for the detection of colorectal PM: narrow-band imaging (NBI), near-infrared indocyanine green fluorescent imaging (NIR-ICG), and spray-dye chromoendoscopy (SDCE).

Methods

Patients with colorectal PM were prospectively included. Prior to cytoreduction and HIPEC, all abdominal regions were inspected with white-light imaging, NBI, NIR-ICG, and SDCE during exploratory laparoscopy. Primary endpoints were sensitivity and specificity for the detection of PM, using pathological examination of biopsied lesions as the reference standard. The safety of all techniques was assessed.

Results

Between May 2016 and March 2018, four different techniques were analyzed in 28 patients, resulting in 169 biopsies. Sensitivity for the detection of PM significantly increased from 80.0% with white light to 96.0% with NBI (p = 0.008), without loss of specificity (74.8% vs. 73.1%, respectively, p = 0.804). The use of NIR-ICG and SDCE was discontinued after 10 patients had undergone treatment because the lesions were not fluorescent using NIR-ICG, and because SDCE did not visualize the whole peritoneum. No adverse events relating to the imaging techniques occurred.

Conclusion

NBI substantially increased the detection of PM. This method is safe and could improve the detection of metastatic lesions and help optimize cytoreduction in patients with colorectal PM.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-7005-5) contains supplementary material, which is available to authorized users.

Prospective Comparative Study of Laparoscopic Narrow Band Imaging (NBI) Versus Standard Imaging in Gynecologic Oncology

BACKGROUND

Narrow band imaging (NBI) is an optic filtration enhancement for endoscopy that uses two wavelengths of light (415 and 540 nm) to highlight superficial microvascular patterns. It has been successfully utilized to improve identification of lesions with abnormal vasculature, which is associated with endometriosis and endometrial cancer. Case studies suggest it may also facilitate surgical staging of gynecologic cancer, which is critical in determining appropriate adjuvant therapies. A technology that enhances the ability to identify metastatic disease during minimally invasive surgery (MIS) could make an important difference in patient outcomes.

METHODS

A prospective comparative study was conducted to evaluate patients with clinical indication for diagnostic or operative laparoscopy. All received white light imaging followed by NBI during the same procedure. Suspicious lesions were examined and photographed, using both modalities, before excision. The two techniques were compared. Positive predictive value, negative predictive value, and diagnostic accuracy in identifying histologically confirmed metastatic lesions were assessed, using appropriate statistical methods.

RESULTS

Of 124 patients enrolled in the study, 94 were evaluable; 30 did not undergo MIS and were therefore excluded. A significantly higher number of peritoneal abnormalities were identified with NBI versus white light imaging (P = 0.0239). However, no statistically significant difference (P = 0.18, patient level) was observed in identification of histologically confirmed metastatic disease.

CONCLUSIONS

NBI imaging provides a unique contrast between peritoneal surface and microvascular patterns. However, the results of this study suggest that NBI-enhanced laparoscopy does not provide superior detection of peritoneal surface malignancy compared with standard white light high-definition laparoscopy.

Specific computed virtual chromoendoscopy for detection of peritoneal carcinomatosis: an animal study

BACKGROUND

Detection of an incipient Peritoneal Carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. The aim of this study was to create a murine model of incipient PC and to explore the PC with Fujinon Intelligent Chromo Endoscopy (FICE) in order to determine the wavelengths of the white light (WL) spectre that offer the highest contrast between PC nodules and surrounding peritoneum.

METHODS

Eighteen BALB/c mice had intraperitoneal injection of murine colonic cancer CT26 cells. Peritoneal exploration with FICE was performed at different times. For each PC nodule, 1 WL and 10 FICE images were recorded. Each image was then divided into its elementary red, green and blue band images. Depending on the FICE channel, each elementary image corresponds to a specific wavelength of the WL spectre. Through numerical analysis of these images, the value of the nodule and the background peritoneum were obtained, and the contrast value was calculated. Contrast values obtained with the different wavelengths were then compared.

RESULTS

PC grew in all the mice. The number as well as the size of PC nodules was increasingly high depending on the day of exploration. Mean PCI was 1.6 ± 1.2 at day 5, 7.7 ± 2.6 at day 8 and 15.0 ± 7.3 at day 10. A total number of 1805 elementary images of PC nodules were analysed. The wavelength that offered the best contrast between PC nodules and background peritoneum was 460 nm with a mean contrast value of 0.240 ± 0.151 (p < 0.0001).

CONCLUSION

This murine model of incipient PC is effective, reliable and reproducible. A monochromatic light with a wavelength at 460 nm offers the highest contrast between PC nodules and background peritoneum, allowing a better detection of PC.

A feasibility study of the use of computed virtual chromoendoscopy for laparoscopic evaluation of peritoneal metastases

BACKGROUND

Detection of an incipient peritoneal carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. Fujinon Intelligent Chromo Endoscopy (FICE) is a spectral image processing technology that enhances the contrast of the target tissue. The aim of this study is to investigate the usefulness of FICE system during peritoneal endoscopy and to establish the optimal FICE preset(s) for peritoneal exploration and PC detection.

METHODS

A total of 561 images corresponding to 51 different areas of PC nodules and normal peritoneum were recorded during peritoneal endoscopies (For each area, one white light endoscopy (WLE) image and 10 FICE images). Three groups of 5 evaluators each: senior surgeons, surgical residents and medical students assessed these images. In a first questionnaire, the evaluators gave a score ranging from 1 to 10 to each image, and the three best FICE channels were determined. In a second questionnaire, five criteria were studied specifically: contrast, brightness, vascular architecture, differentiation between organs and detection of PC. The evaluators ranked the WLE and the three best FICE channel images according to these criteria.

RESULTS

The three best FICE channels were channels 6, 2 and 9 with mean scores of 6.21 ± 1.59, 6.17 ± 1.48 and 6.06 ± 1.52, respectively. FICE Channel 2 was superior to WLE and other FICE channels, in terms of contrast (p < 10^-4), visualization of vascular architecture (p < 10^-4), differentiation between organs (p < 10^-4) and detection of PC (p < 10^-4); and ranked first in 38.8, 41.5, 31 and 46.9 % of the cases, respectively.

CONCLUSION

FICE system provides adequate illumination of the abdominal cavity and a unique contrast that enhances the vascular architecture. FICE Channel 2 is the optimal channel for peritoneal exploration and could be a useful tool for the diagnosis of PC during peritoneal explorations.