Sentinel lymph node mapping in colon cancer using radiocolloid as a single tracer: a feasibility study. Nucl Med Commun. 2012;33:832-837. [PMID: 22743586 DOI: 10.1097/mnm.0b013e328353bc0c]

Lymphatic Mapping in Colon Cancer Depending on Injection Time and Tracing Agent: A Systematic Review and Meta-Analysis of Prospective Designed Studies

An optimized lymph node yield leads to better survival in colon cancer, but extended lymphadenectomy is not associated with survival benefits. Lymphatic mapping shows several colon cancers feature aberrant drainage pathways inducing local recurrence when not resected. Currently, different protocols exist for lymphatic mapping procedures. This meta-analysis assessed which protocol has the best capacity to detect tumor-draining and possibly metastatic lymph nodes. A systematic review was conducted according to PRISMA guidelines, including prospective trials with in vivo tracer application. The risk of bias was evaluated using the QUADAS-2 tool. Traced lymph nodes, total resected lymph nodes, and aberrant drainage detection rate were analyzed. Fifty-eight studies met the inclusion criteria, of which 42 searched for aberrant drainage. While a preoperative tracer injection significantly increased the traced lymph node rates compared to intraoperative tracing (30.1% (15.4, 47.3) vs. 14.1% (11.9, 16.5), p = 0.03), no effect was shown for the tracer used (p = 0.740) or the application sites comparing submucosal and subserosal injection (22.9% (14.1, 33.1) vs. 14.3% (12.1, 16.8), p = 0.07). Preoperative tracer injection resulted in a significantly higher rate of detected aberrant lymph nodes compared to intraoperative injection (26.3% [95% CI 11.5, 44.0] vs. 2.5% [95% CI 0.8, 4.7], p < 0.001). Analyzing 112 individual patient datasets from eight studies revealed a significant impact on aberrant drainage detection for injection timing, favoring preoperative over intraoperative injection (OR 0.050 [95% CI 0.010-0.176], p < 0.001) while indocyanine green presented itself as the superior tracer (OR 0.127 [95% CI 0.018-0.528], p = 0.012). Optimized lymphatic mapping techniques result in significantly higher detection of aberrant lymphatic drainage patterns and thus enable a personalized approach to reducing local recurrence.

The impact of laparoscopic, open, extended right, and left colectomy on clinical outcomes of splenic flexure colon cancer: A meta-analysis

BACKGROUND

Surgical intervention is the recommended line for the management of colon cancer. The aim of this study was to evaluate the impact of different surgical techniques (laparoscopic, open, extended right, and left colectomy) on clinical outcomes such as mortality, postoperative complications, operation and hospitalization time, and oncological factors.

METHODS

A total of 15 studies have been included in the current study. The outcomes of these studies were analyzed using a random-effect model and it was used to calculate the mean difference with 95% confidence intervals to quantify the impact of open, laparoscopic, extended right, and left colectomy. Inclusion criteria included studies in which subjects undergo splenic flexure colon cancer surgery with 2 comparable different surgical techniques.

RESULTS

Laparoscopic splenic flexure colon cancer surgery showed a significant beneficial impact on the length of hospital stay (P < .001), the volume of blood loss during surgery (P < .001), postoperative complications (P < .001), and time to an oral diet (P < .001). On the other hand, there was no significance regarding anastomotic leakage, infection of the surgical site, and operation time. Regarding the comparison between extended right colectomy (ERC) and lift colectomy (LC), analysis findings showed a significant (P = .001) higher efficacy of ERC in harvested number of lymph nodes compared with LC. On the other hand, there was no significant difference for the rest of the parameters. The neoadjuvant therapy as an influencing factor on postoperative outcome showed a beneficial impact regarding the overall survival rate.

CONCLUSION

Laparoscopic splenic flexure colon cancer surgery showed a significant beneficial impact compared with open surgery as proved by clinical outcomes. On the other hand, ERC and LC resulted in similar findings except for harvested lymph nodes, results were in favor of ERC.

Role of near-infrared fluorescence in colorectal surgery

Near-infrared fluorescence (NIRF) is a technique of augmented reality that, when applied in the operating theatre, allows the colorectal surgeon to visualize and assess bowel vascularization, to identify lymph nodes draining a cancer site and to identify ureters. Herein, we review the literature regarding NIRF in colorectal surgery.

Sentinel lymph node mapping for metastasis detection in colorectal cancer: a systematic review and meta-analysis

INTRODUCTION

controversy exists on the diagnostic performance of sentinel lymph node (SLN) mapping in colorectal cancer. This study aimed to provide a more precise estimation of its clinical significance.

MATERIALS AND METHODS

a systematic search of electronic databases was conducted to retrieve all relevant studies up to August 31st, 2019. Detection rate, sensitivity, and upstaging rate were pooled together, and a subgroup analysis was performed to identify factors that affect diagnostic performance. The prognostic value of upstaging was also explored.

RESULTS

sixty-eight studies were eligible and included. The pooled SLN detection rate was 0.93 (95 % CI, 0.91-0.94), with a significant higher rate in colon cancer or in studies including more than 100 patients. The overall sensitivity of the SLN procedure in colorectal cancer was 0.72 (95 % CI, 0.67-0.77). The tracers used were found to influence sensitivity. A mean weighted upstaging of 0.22 (95 % CI, 0.18-0.25) was identified. True upstaging, defined as micro-metastases, was 14 %. Upstaged patients were associated with worse overall survival (OS) when compared with node-negative patients (HR = 2.60, 95 % CI, 0.16-4.63). In addition, upstaged patients had a lower 5-year disease-free survival (DFS) rate than node-negative patients.

CONCLUSION

based on the results of the present meta-analysis, the SLN mapping procedure should focus on early stage patients to refine staging, since upstaging appeared to be a prognostic factor for DFS and OS. The SLN procedure can be recommended for colorectal cancer patients in addition to conventional resection.

Perioperative PET/CT lymphoscintigraphy and fluorescent real-time imaging for sentinel lymph node mapping in early staged colon cancer

Purpose

Using current optical imaging techniques and gamma imaging modalities, perioperative sentinel lymph node (SLN) identification in colon cancer can be difficult when the SLN is located near the primary tumour or beneath a thick layer of (fat) tissue. Sentinel lymph node mapping using PET/CT lymphoscintigraphy combined with real-time visualization of the SLN using near-infrared imaging has shown promising results in several types of cancer and may facilitate the successful identification of the number and location of the SLN in early colon cancer.

Methods

Clinical feasibility of PET/CT lymphoscintigraphy using preoperative endoscopically injected [⁸⁹Zr]Zr-Nanocoll and intraoperative injection of the near-infrared (NIR) tracer Indocyanine Green (ICG) was evaluated in ten early colon cancer patients. Three preoperative PET/CT scans and an additional ex vivo scan of the specimen were performed after submucosal injection of [⁸⁹Zr]Zr-Nanocoll. All SLNs and other lymph nodes underwent extensive pathological examination for metastases. A histopathological proven lymph node visible at preoperative PET/CT and identified at PET/CT of the specimen was defined as SLN.

Results

A total of 27 SLNs were harvested in seven out of eight patients with successful injection of both tracers. In one patient no SLNs were assigned preoperatively. In two patients injection of [⁸⁹Zr]Zr-Nanocoll failed due to incorrect needle positioning. Twenty-one (78%) SLNs were found intraoperatively using NIR-imaging. Eleven of the 27 (41%) SLNs were located near the primary tumour (< 2 cm). Those six SLNs not found intraoperatively with NIR-imaging were all located close to the tumour. In all seven patients at least one SLN could be assigned at preoperative imaging 24 h after tracer administration. One SLN contained metastases detected by immunohistochemistry. No metastases were found in the non-SLNs.

Conclusions

This study shows the potential of preoperative PET/CT lymphoscintigraphy to inform the surgeon about the number and location of SLNs in patients with early colon cancer. The additional use of NIR-imaging allows for intraoperative identification of these SLNs which are invisible with conventional white light imaging. Further research is necessary to improve and simplify the technique. We recommend perioperative SLN identification using a preoperative lymphoscintigraphy scan just before surgery approximately 24 h after injection. Additionally a postoperative scan of the specimen combined with intraoperative real-time NIR-imaging should be performed.

Electronic supplementary material

The online version of this article (10.1007/s00259-019-04284-w) contains supplementary material, which is available to authorized users.

Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis

This review aimed to determine the overall sensitivity and specificity of indocyanine green (ICG) near-infrared (NIR) fluorescence in sentinel lymph node (SLN) detection in Colorectal cancer (CRC). A systematic search in electronic databases was conducted. Twelve studies including 248 patients were reviewed. The median sensitivity, specificity, and accuracy rates were 73.7, 100, and 75.7. The pooled sensitivity and specificity rates were 71% and 84.6%. In conclusion, ICG-NIR fluorescence is a promising technique for detecting SLNs in CRC.

Surgical Treatment of Colon Cancer of the Splenic Flexure: A Systematic Review and Meta-analysis

This is a systematic review and meta-analysis on the surgical treatments of splenic flexure carcinomas (SFCs). Medline, EMBASE, and Scopus were searched from January 1990 to May 2016. Studies of at least 5 patients comparing extended right colectomy (ERC) versus left colectomy (LC) and/or laparoscopy versus open surgery for SFCs were retrieved and analyzed. Overall, 12 retrospective studies were selected, including 569 patients. ERC was performed in 23.2% of patients, whereas LC in 76.8%. Pooled data suggested that ERC and LC had similar oncologic quality of resection and postoperative outcomes. Laparoscopy was used in 50.6% of patients (conversion rate: 2.5%) and it was associated with significantly shorter time to oral diet, fewer postoperative complications, and shorter hospital stay than open surgery. In conclusion, the optimal extent of SFC surgical resection, that is, ERC or LC remains under debate. However, laparoscopy provides better postoperative outcomes and fewer postoperative complications than open surgery.

Sentinel Lymph Node Detection in Colorectal Cancer - First Experience

BACKGROUND:

Colorectal cancer (CRC) is the second commonest cancer in women, the third in men, being the fourth commonest cause of cancer death. The most important factor for prognosis and staging in CRC patients is the status of the regional lymph nodes (LN).

AIM:

To implement the method for sentinel lymph node (SLN) detection in CRC patients using radiocolloid, and test its detection rate, sensitivity, accuracy, negative predictive value and the possibility for upstaging.

MATERIAL AND METHODS:

The study included 40 CRC patients, age 63 ± 14 years, without LNs detected on CT or MRI. SLN detection was performed after endoscopically peri- and intratumoral injection of 99mTc-SENTISCINT. All patients underwent resection with systemic lymphadenectomy, and the SLNs were detected ex vivo. Pathohistology was performed to all resected LNs.

RESULTS:

The identification rate was 95%, the accuracy of the procedure was 92.1%, the negative predictive value was 86.95%, the sensitivity was 83.3%, and the upstage was 22.5%.

CONCLUSION:

Identification of SLNs in CRC patients with this method is possible and the detection rate, negative predictive value, accuracy and sensitivity are reliable. We expect to contribute in the upstaging of stage II CRC patients and the selection of appropriate oncology treatment protocols.

Characteristics of magnetic probes for identifying sentinel lymph nodes

The identification of the sentinel lymph nodes that cause tumor metastasis is important in breast cancer therapy. The detection of magnetic fluid accumulating in the lymph nodes using a magnetic probe allows surgeons to identify the lymph nodes. In this study, we carried out numerical simulations and experiments to investigate the sensitivity and basic characteristics of a magnetic probe consisting of a permanent magnet and a small magnetic sensor. The measured magnetic flux density arising from the magnetic fluid agreed well with the numerical results. In addition, the results helped realize an appropriate probe configuration for achieving high sensitivity to magnetic fluid. A prototype probe detected magnetic fluid located 30 mm from the probe head.

Qualitative and quantitative issues of lymph nodes as prognostic factor in colon cancer

For patients undergoing curative resections for colon cancer, the nodal status represents the strongest prognostic factor, yet at the same time the most disputed issue as well. Consequently, the qualitative and quantitative aspects of lymph node evaluation are thus being scrutinized beyond the blunt distinction between 'node positive' (pN+) and 'node negative' (pN0) disease. Controversy ranges from a minimal or 'least-unit' strategy as exemplified by the 'sentinel node' to a maximally invasive or 'all inclusive' approach by extensive surgery. Ranging between these two extremes of node sampling strategies are factors of quantitative and qualitative value, which may be subject to modification. Qualitative issues may include aspects of lymph node harvest reflected by surgeon, pathologist and even hospital performance, which all may be subject to modification. However, patient's age, gender and genotype may be non-modifiable, yet influence node sample. Quantitative issues may reflect the balance between absolute numbers and models investigating the relationships of positive to negative nodes (lymph node ratio; log odds of positive lymph nodes). This review provides an updated overview of the current controversies and a state-of-the-art perspective on the qualitative and quantitative aspects of using lymph nodes as a prognostic marker in colon cancer.