Image-enhanced laparoscopy: A promising technology for detection of peritoneal micrometastases

Hysteroscopic Photodynamic Diagnosis Using 5-Aminolevulinic Acid: A High-Sensitivity Diagnostic Method for Uterine Endometrial Malignant Diseases

STUDY OBJECTIVE

To examine the diagnostic accuracy of hysteroscopic photodynamic diagnosis (PDD) using 5-aminolevulinic acid (5ALA) in patients with endometrial cancer and premalignant atypical endometrial hyperplasia.

DESIGN

A single-center, open-label, exploratory intervention study.

SETTING

University Hospital in Japan.

PATIENTS

Thirty-four patients who underwent hysteroscopic resection in the Department of Obstetrics and Gynecology at Keio University Hospital.

INTERVENTIONS

Patients were given 5ALA orally approximately 3 hours before surgery and underwent observation of the uterine cavity and endometrial biopsy using 5ALA-PDD during hysteroscopic resection. Specimens were diagnosed histopathologically and the diagnostic sensitivity and specificity of hysteroscopic 5ALA-PDD for malignancy in the uterine cavity was determined. Red (R), blue (B), and green (G) intensity values were determined from PDD images, and the relationships of histopathological diagnosis with these values were used to develop a model for objective diagnosis of uterine malignancy.

MEASUREMENTS AND MAIN RESULTS

Three patients were excluded from the study because of failure of the endoscope system. A total of 113 specimens were collected endoscopically. The sensitivity and specificity of 5ALA-PDD for diagnosis of malignancy in the uterine cavity were 93.8% and 51.9%, respectively. The R/B ratio in imaging analysis was highest in malignant lesions, followed by benign lesions and normal uterine tissue, with significant differences among these groups (p <.05). The R/B and G/B ratios were used in a formula for prediction of malignancy based on logistic regression and the area under the receiver operating characteristic curve for this formula was 0.838. At a formula cutoff value of 0.220, the sensitivity and specificity for diagnosis of malignant disease were 90.6% and 65.4%, respectively.

CONCLUSION

To our knowledge, this is the first study of the diagnostic accuracy of 5ALA-PDD for malignancies in the uterine cavity. Hysteroscopic 5ALA-PDD had higher sensitivity and identifiability of lesions. These findings suggest that hysteroscopic 5ALA-PDD may be useful for diagnosis of minute lesions.

Two-photon images reveal unique texture features for label-free identification of ovarian cancer peritoneal metastases

For cancer patients, treatment selection fundamentally relies on staging, with "under-staging" considered a common problem. Imaging modalities that can complement conventional white-light laparoscopy are needed to detect more accurately small metastatic lesions in patients undergoing operative cancer care. Biopsies from healthy parietal peritoneum and ovarian peritoneal metastases obtained from 8 patients were imaged employing a two-photon laser scanning microscope to generate collagen-second harmonic generation (SHG) and fluorescence images at 755 nm and 900 nm excitation and 460 ± 20 nm and 525 ± 25 nm emission. Forty-one images were analyzed by automated image processing algorithms and statistical textural analysis techniques, namely gray level co-occurrence matrices. Two textural features (contrast and correlation) were employed to describe the spatial intensity variations within the captured images and outcomes were used for discriminant analysis. We found that healthy tissues displayed large variations in contrast and correlation features as a function of distance, corresponding to repetitive, increased local intensity fluctuations. Metastatic tissue images exhibited decreased contrast and correlation related values, representing more uniform intensity patterns and smaller fibers, indicating the destruction of the healthy stroma by the cancerous infiltration. The textural outcomes resulted in high classification accuracy as evaluated quantitatively by discriminant analysis.

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.

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.

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

BACKGROUND

Selection of cancer treatment fundamentally relies on staging of the underlying malignancy. The aim of this study was to evaluate the feasibility and effectiveness of laparoscopic narrow band imaging (NBI) for operative staging and detection of occult peritoneal cancer metastases.

METHODS

A randomized, controlled feasibility trial with crossover design evaluating adult patients with gastrointestinal or gynecologic malignancies who have a clinical indication for diagnostic laparoscopy was conducted. Twenty-three patients were randomized to white-light followed by NBI laparoscopy (n = 11) or NBI followed by white-light laparoscopy (n = 12) using the Olympus Evis Exera II system. Three patients were excluded from analysis.

RESULTS

In all 20 study patients, the abdominal cavity was sufficiently illuminated. An enhanced contrast of microvasculature and organ surface pattern was appreciated. Eight of the 20 patients (40%) were found to have metastases of the peritoneal surface. While NBI did not show any additional peritoneal lesions, 2 of the 63 suspicious-appearing nodules seen on white-light imaging were not visible on NBI (p = 0.50). The median diameter of all the nodules identified was 2 mm (range 1-50 mm) and was identical with each method.

CONCLUSIONS

The information from this feasibility study demonstrated that NBI provides adequate illumination of the abdominal cavity and a unique contrast that enhances microvasculature and architectural surface pattern. The results suggest that NBI laparoscopy is not superior in detecting peritoneal metastases compared to standard white-light laparoscopy, but might provide a technology that could be applied for other abdominal pathologies.

From shadow to light: visualization of extrahepatic bile ducts using image-enhanced laparoscopy

BACKGROUND

Correct recognition of the extrahepatic bile ducts is thought to be crucial to reduce the risk of bile duct injuries during various laparoscopic procedures. Image-enhanced laparoscopy techniques, utilizing various optical modalities other than white light, may help in detecting structures "hidden" underneath connective tissue.

METHODS

A systematic literature search was conducted of studies describing image-enhanced laparoscopy techniques for visualization of the extrahepatic bile ducts.

RESULTS

In all, 29 articles met inclusion criteria. They describe various techniques in the animal or human setting, including autofluorescence imaging, drug-enhanced fluorescence imaging, infrared thermography, and spectral imaging. This review describes these various techniques and their results.

CONCLUSION

Image-enhanced laparoscopy techniques for real-time visualization of extrahepatic bile ducts are still in its infancy. Out of the techniques currently described, indocyanine green-enhanced near-infrared fluorescence laparoscopy has the most mature results, but other techniques also appear promising. It can be expected that in the future, image-enhanced laparoscopy might become a routine adjunct to any white-light laparoscopic operation near the hepatic hilum.

Staging laparoscopy in pancreatic cancer: a potential role for advanced laparoscopic techniques

BACKGROUND

The role of staging laparoscopy in pancreatic cancer in the age of high-resolution CT scans is under debate. This study's aim is to evaluate the efficacy of staging laparoscopy in this disease.

STUDY DESIGN

A retrospective cohort study was conducted evaluating patients who underwent operative treatment for radiographic stage I to III pancreatic cancer between July 2003 and October 2012. Radiographic follow-up was 94% at 6 months.

RESULTS

Of 274 patients who met inclusion criteria, 136 underwent staging laparoscopy, which identified radiographic occult distant metastases in 2% (3 of 136). However, subsequent laparotomy identified an additional 9% (12 of 136) harboring distant metastases in regions not visualized on standard staging laparoscopy; specifically, the posterior liver surface, paraduodenal retroperitoneum, proximal jejunal mesentery, and lesser sac. The remaining 138 patients underwent initial staging laparotomy, which showed similar results identifying radiographic occult distant disease in 11% (15 of 138). Within 6 months after the operation, peritoneal or subcapsular liver metastases developed in an additional 6% (15 of 257)-disease that potentially could have been diagnosed at the time of operation-providing a false-negative rate of 88% for staging laparoscopy compared with 36% for staging laparotomy.

CONCLUSIONS

Despite the availability of high-resolution CT scans, occult distant metastases can still be found in 11% of patients during the operation. In the absence of reliable risk factors to predict distant metastases, staging laparoscopy should be offered to all patients with radiographic localized disease. However, the results favor extended laparoscopic staging with evaluation of the posterior liver surface, mobilization of the duodenum, evaluation of the proximal jejunal mesentery, and visualization of the lesser sac.