Indocyanine Green Guided Pelvic Lymph Node Dissection: An Efficient Technique to Classify the Lymph Node Status of Patients with Prostate Cancer Who Underwent Radical Prostatectomy

Efficacy of indocyanine green fluorescence-guided inguinal lymph node dissection for penile cancer: a randomised trial

OBJECTIVES

To investigate the safety and efficacy of indocyanine green (ICG) fluorescence-guided inguinal lymph node dissection (ILND) in patients with penile cancer.

PATIENTS AND METHODS

A prospective, single-blind, randomised controlled clinical trial (ChiCTR2100044584) was performed among patients with penile caner who underwent bilateral modified ILND at four centres in China between 1 April 2021 and 30 June 2022. Patients aged 18-80 years and diagnosed with squamous cell carcinomas were included. Each enrolled patient was randomly assigned to either ICG fluorescence-guided ILND by a laparoscopic or robot-assisted approach in one groin, with non-ICG fluorescence-guided ILND in the other groin acting as a control. The primary outcome was the number of retrieved ILNs. Secondary outcomes included complications according to the Clavien-Dindo classification and the ILN non-compliance (inadequate removal of ILNs) rate.

RESULTS

A total of 45 patients were included in the intention-to-treat (ITT) analysis, and the 42 who completed the entire study were included in the per protocol (PP) analysis. There were no ICG-related complications in any of the patients. The results of the ITT and PP analyses indicated that the total number of unilateral ILNs retrieved was higher on the ICG side than on the non-ICG side (mean 13 vs 9 ILNs, difference 4 ILNs [95% CI 2.7-4.4], P = 0.007), and the number of unilateral deep and superficial ILNs was higher on the ICG side. Furthermore, the LN non-compliance rate was lower on the ICG side than on the non-ICG side. Additionally, there was no significant difference in local complications in the groins between the two sides (P > 0.05).

CONCLUSION

An ICG fluorescence-guided ILND was safe for patients with penile cancer. This procedure can improve the number of ILNs retrieved and reduce the LN non-compliance rate without increased complications. ICG fluorescence-guided ILND is beneficial and recommended for selected patients with penile cancer.

Personalised indocyanine-guided lymphadenectomy for prostate cancer: a randomised clinical trial

OBJECTIVES

To study the safety and efficacy of a personalised indocyanine-guided pelvic lymph node dissection (PLND) against extended PLND (ePLND) during radical prostatectomy (RP).

PATIENTS AND METHODS

Patients who were candidates for RP and lymphadenectomy, with intermediate- or high-risk prostate cancer (PCa) according to the National Comprehensive Cancer Network guidelines, were enrolled in this randomised clinical trial. Randomisation was made 1:1 to indocyanine green (ICG)-PLND (only ICG-stained LNs) or ePLND (obturator fossa, external, internal, and common iliac and presacral LNs). The primary endpoint was the complication rate within 3 months after RP. Secondary endpoints included: rate of major complications (Clavien-Dindo Grade III-IV), time to drainage removal, length of stay, percentage of patients classified as pN1, number of LNs removed, number of metastatic LNs, rate of patients with undetectable prostate-specific antigen (PSA), biochemical recurrence (BCR)-free survival, and rate of patients with androgen-deprivation therapy at 24 months.

RESULTS

A total of 108 patients were included with a median follow-up of 16 months. In all, 54 were randomised to ICG-PLND and 54 to ePLND. The postoperative complication rate was higher in the ePLND (70%) vs the ICG-PLND group (32%) (P < 0.001). Differences between major complications in both groups were not statically significant (P = 0.7). The pN1 detection rate was higher in the ICG-PLND group (28%) vs the ePLND group (22%); however, this difference was not statistically significant (P = 0.7). The rate of undetectable PSA at 12 months was 83% in the ICG-PLND vs 76% in the ePLND group, which was not statistically significant. Additionally, there were no statistically significant differences in BCR-free survival between groups at the end of the analysis.

CONCLUSIONS

Personalised ICG-guided PLND is a promising technique to stage patients with intermediate- and high-risk PCa properly. It has shown a lower complication rate than ePLND with similar oncological outcomes at short-term follow-up.

Development and validation of novel nomogram to identify the candidates for extended pelvic lymph node dissection for prostate cancer patients in the robotic era

OBJECTIVES

To determine candidates for extended pelvic lymph node dissection using a novel nomogram to assess the risk of lymph node invasion in Japanese prostate cancer patients in the robotic era.

METHODS

A total of 538 patients who underwent robot-assisted radical prostatectomy with extended pelvic lymph node dissection in three hospitals were retrospectively analyzed. Medical records were reviewed uniformly and the following data collected: prostate-specific antigen, age, clinical T stage, primary and secondary Gleason score at prostate biopsy, and percentage of positive core numbers. Finally, data from 434 patients were used for developing the nomogram and data from 104 patients were used for external validation.

RESULTS

Lymph node invasion was detected in 47 (11%) and 16 (15%) patients in the development and validation set, respectively. Based on multivariate analysis, prostate-specific antigen, clinical T stage ≥3, primary Gleason score, grade group 5, and percentage of positive cores were selected as variables to incorporate into the nomogram. The area under the curve values were 0.781 for the internal and 0.908 for the external validation, respectively.

CONCLUSIONS

The present nomogram can help urologists identify candidates for extended pelvic lymph node dissection concomitant with robot-assisted radical prostatectomy among patients with prostate cancer.

Sentinel Lymph Node Techniques in Urologic Oncology: Current Knowledge and Application

Lymph node (LN) metastases have a significant negative impact on the prognosis of urological malignancies. Unfortunately, current imaging modalities are insufficient when it comes to detecting micrometastases; thus, surgical LN removal is commonly used. However, there is still no established ideal lymph node dissection (LND) template, leading to unnecessary invasive staging and the possibility of missing LN metastases located outside the standard template. To address this issue, the sentinel lymph node (SLN) concept has been proposed. This technique involves identifying and removing the first group of draining LNs, which can accurately stage cancer. While successful in breast cancer and melanoma, the SLN technique in urologic oncology is still considered experimental due to high false-negative rates and lack of data in prostate, bladder, and kidney cancer. Nevertheless, the development of new tracers, imaging modalities, and surgical techniques may improve the potential of the SLN procedures in urological oncology. In this review, we aim to discuss the current knowledge and future contributions of the SLN procedure in the management of urological malignancies.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

The application of indocyanine green in guiding prostate cancer treatment

Objective

Indocyanine green (ICG) with near-infrared fluorescence absorption is approved by the United States Food and Drug Administration for clinical applications in angiography, blood flow evaluation, and liver function assessment. It has strong optical absorption in the near-infrared region, where light can penetrate deepest into biological tissue. We sought to review its value in guiding prostate cancer treatment.

Methods

All related literature at PubMed from January 2000 to December 2020 were reviewed.

Results

Multiple preclinical studies have demonstrated the usefulness of ICG in identifying prostate cancer by using different engineering techniques. Clinical studies have demonstrated the usefulness of ICG in guiding sentinel node dissection during radical prostatectomy, and possible better preservation of neurovascular bundle by identifying landmark prostatic arteries. New techniques such as adding fluorescein in additional to ICG were tested in a limited number of patients with encouraging result. In addition, the use of the ICG was shown to be safe. Even though there are encouraging results, it does not carry sufficient sensitivity and specificity in replacing extended pelvic lymph node dissection during radical prostatectomy.

Conclusion

Multiple preclinical and clinical studies have shown the usefulness of ICG in identifying and guiding treatment for prostate cancer. Larger randomized prospective studies are warranted to further test its usefulness and find new modified approaches.

Diagnostic Value of Radio-Guided Sentinel Node Detection in Patients with Prostate Cancer Undergoing Radical Prostatectomy with Modified-Extended Lymphadenectomy

Background. In many malignancies, sentinel lymph node dissection (SLND) is being used as a nodal staging tool. We prospectively evaluated the diagnostic value of radio-guided sentinel lymph node (SLN) detection in patients with prostate cancer (PCa). This study aimed to investigate the reliability of the radio-guided SLN detection technique for perioperative localization of LNs metastases as well as to map lymphatic drainage patterns of the prostate. Methods. Forty-three patients with intermediate- or high-risk cN0cM0 PCa at conventional imaging underwent radical prostatectomy with modified-extended pelvic lymph node dissection (mePLND). A day before the planned surgery, a Tc-99m nanocolloid was injected into the prostate under the control of transrectal ultrasonography (TRUS). Preoperative single-photon emission computed tomography (SPECT-CT) imaging and intraoperative gamma-probe were used to identify SLNs. All positive lesions were excised, followed by mePLND. The excised lymph nodes (LNs) were then submitted for histopathological examination, which was used as a reference for the calculation of diagnostic parameters of the SLN technique for SPECT-CT and the intraoperative gamma-probe. Results. In total, 119 SLNs were detected preoperatively (SPECT-CT) and 118 intraoperatively (gamma-probe). The study revealed that both SLN detection techniques showed a sensitivity of 90% and a specificity of 6.06%. The negative predictive value (NPV) was 66.67%. SLN technique would have correctly staged nine of 10 patients, which is the same result as in the case of limited LND. However, it allowed the removal of all metastatic nodes only in four of them. SLND would have comprised 69.7% of preoperatively detected LNs, and removed 13 out of 19 positive LNs (68.42%), respectively. Conclusions. Radio-guided SLND has a low diagnostic rate and is a poor staging tool. ePLND remains the gold standard in nodal metastases assessment in PCa. Our study indicates that lymphatic drainage of the prostate and actual metastasis routes may vary significantly.

Sentinel Lymph Node Biopsy in Prostate Cancer Patients: Results From an Injection Technique Targeting the Index Lesion in the Prostate Gland

Objectives

To determine the accuracy of nodal staging in patients with prostate cancer (PCa) when ^99mTc-nanocolloid radiotracer is injected into an index lesion (IL).

Methods

This prospective study was conducted at our institution between June 2016 and October 2020. It included 64 patients with localized PCa with at least a 5% possibility for lymph node involvement in the Memorial Sloan Kettering Cancer Center nomogram, suitable for surgical treatment. All patients underwent magnetic resonance imaging (MRI) with IL and were pathologically confirmed. The day before surgery, transrectal ultrasound-guided injection (TRUS) of ^99mTc-nanocolloid into the IL was performed. Surgical procedures included radical prostatectomy (RP), sentinel lymph node biopsy (SLNB), and extended pelvic lymphadenectomy (ePLND). Analysis was performed, including histopathological findings of RP, ePLND, and SLNB. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), false negative (FN), false positive (FP), diagnostic yield, and non-diagnostic rate were calculated.

Results

A total of 1,316 lymph nodes were excised, including 1,102 from the ePLND (83.7%) and 214 (16.3%) sentinel lymph nodes (SLN). 26 SLN were dissected outside the ePLND template. The final pathology demonstrated 46 (3.5%) lymph node metastasis, 31 (67.4%) in the SLNB and 15 (32.6%) in the non-SLN ePLND. At the patient level, 18 (28.1%) patients had pN1. With a mean follow-up of 33.1 months, 4/19 (21.1%) pN1 patients had undetectable PSA, and 3/19 (15.8%) had a PSA < 0.1 ng/mL. Lymph node dissection included 20.6 lymph nodes per patient (IQR 15–24.2), with 3.3 SLNB nodes per patient (IQR 2–4.2). PPV and NPV were 100 and 97.8%, respectively. Sensitivity and specificity were 94.4 and 100%, respectively. FN was 5.5% and FP was 4.3%. Diagnostic yields were 95.3% and the non-diagnostic rate was 4.7%.

Conclusion

Radiotracer injection into the prostate IL offers promising results for staging purposes in cases in which ePLND is considered. Negative SLNB is a predictor of negative ePLND. Patients with a limited burden of nodal metastasis have a significant chance of remaining free of biochemical recurrence at mid-term follow-up.

Diagnostic Performance of Preoperative Choline-PET/CT in Patients Undergoing Salvage Lymph Node Dissection for Recurrent Prostate Cancer: A Multicenter Experience

We aimed to retrospectively analyze consecutive prostate cancer patients diagnosed with biochemical or clinical recurrence after local treatment with curative intent, with no evidence of distant metastases, who underwent positron emission tomography/computed tomography (PET/CT) with choline followed by salvage lymph node dissection (SLND) in three academic centers between 2013 and 2020. A total of 27 men were included in the analyses. Sensitivity, specificity, positive and negative predictive values, and accuracy of choline-PET/CT in predicting pathology-proven lymph node involvement were 75%, 43%, 79%, 38% and 67% on per-patient and 70%, 86%, 80%, 78%, and 79% on per-site analyses, respectively, with the differences in specificity and NPV between per-patient and per-site analyses being statistically significant (p = 0.03 and 0.04, respectively). The study provides further insight into the role of preoperative choline-PET/CT in patients undergoing SLND for recurrent PC.

Performance of Indocyanine Green Fluorescence for Detecting Lymph Node Metastasis in Prostate Cancer: A Systematic Review and Meta-analysis

PURPOSE

The use of sentinel lymph node dissection in several cancers has been gaining attention with the emergence of indocyanine green fluorescence. We performed a meta-analysis to assess the diagnostic performance of indocyanine green fluorescence in detecting lymph node metastasis in prostate cancer patients.

METHODS

A literature search was conducted using PubMed, Cochrane Library, and SCOPUS on November 30, 2020, to identify eligible studies. Studies were eligible if they investigated the diagnostic performance of indocyanine green fluorescence before pelvic lymph node dissection in prostate cancer patients and reported the number of true positives, false positives, false negatives, and true negatives on lymph node-based analysis in comparison to histopathologic findings in the dissected specimen.

RESULTS

Our systematic review covered 11 studies published between 2011 and 2020, with 519 patients, and our meta-analysis included 9 studies with 479 patients. Based on lymph node analysis of indocyanine green fluorescence, the results showed pooled sensitivity and specificity at 0.75 (95% confidence interval [CI] 0.49 to 0.90) and 0.66 (95% CI 0.61 to 0.70), respectively. The diagnostic odds ratio was 6.0 (95%CI 2 to 21). Several lymphatic drainage routes also showed sentinel lymph nodes localized outside the ordinal pelvic lymph node template.

CONCLUSIONS

We noted relatively low diagnostic performance for lymph node metastasis, suggesting that indocyanine fluorescence may not currently be a viable alternative to pelvic lymph node dissection in prostate cancer patients. However, this technique shows novel lymphatic drainage routes and underscores the importance of lymph nodes not removed in ordinary dissection.

Indocyanine green guidance improves the efficiency of extended pelvic lymph node dissection during laparoscopic radical prostatectomy

OBJECTIVES

To evaluate whether indocyanine green guidance can improve the quality of extended pelvic lymph node dissection in patients undergoing radical prostatectomy.

METHODS

A total of 214 patients underwent laparoscopic radical prostatectomy with indocyanine green-guided lymph node dissection plus extended pelvic lymph node dissection. These patients (group A) were matched 1:1 for clinical risk groups according to the National Comprehensive Cancer Network classification with patients who underwent the same procedure without fluorescence guidance (group B). Biochemical recurrence was defined as two consecutive prostate-specific antigen rises of at least 0.2 ng/mL. The Kaplan-Meier method and Cox regression models were used to identify predictors of biochemical recurrence.

RESULTS

The median number of retrieved nodes was significantly higher in group A (22 vs 14, P < 0.001). The rate of lymph node metastases was higher in group A (65.9% vs 34.1%, P = 0.01). Increasing the yield of lymph node dissection was independently and negatively correlated with the biochemical recurrence risk in both overall and pN-positive patients (hazard ratio 0.97, P = 0.03; and hazard ratio 0.95, P = 0.02). The 5-year biochemical recurrence-free survival rates were (75.8% vs 65.9, P = 0.09) and (54.1% vs 24.9%, P = 0.023) for group A and group B in the overall cohort and pN-positive cohort, respectively.

CONCLUSION

Indocyanine green-guided lymph node dissection plus extended pelvic lymph node dissection improves identification of lymphatic drainage, resulting in a higher number of lymph nodes and retrieved lymph node metastases, and allowing a more accurate local staging and a prolonged biochemical recurrence-free survival.

Salvage Pelvic Lymph Node Dissection and Current State of Imaging for Recurrent Prostate Cancer: Does a Standard Exist?

PURPOSE OF REVIEW

We aim to evaluate the efficacy of salvage lymph node dissection (SLND) for nodal recurrent prostate cancer after primary treatment. We also provide a review of the diagnostic performance of next-generation sequencing (next-generation imaging (NGI)) radiotracers in the salvage setting.

RECENT FINDINGS

Most studies evaluating SLND include a heterogeneous population with a small sample size and are retrospective in design. The 5-year clinical recurrence-free and cancer-specific survival following SLND are 26-52% and 57-89%, respectively, among prospective studies. NGI improves accuracy in detecting nodal recurrence compared to conventional CT, with PMSA PET-CT showing the most promise. However, limited studies exist comparing imaging modalities and performance is variable at low PSA values. SLND is a promising treatment option, but more prospective data are needed to determine the ideal surgical candidate and long-term oncologic outcomes. More studies comparing different NGI are needed to determine the best imaging modality in patients who may be candidates for salvage treatment.

Techniques of robotic radical prostatectomy for the management of prostate cancer: which one, when and why

The advent of robotic assistance in surgery has completely revolutionized the surgical management of prostate cancer. It enables precise dissection and reconstruction in order to maximize oncological and functional outcomes. In many parts of the world, robot-assisted laparoscopic radical prostatectomy has evolved to become the surgical standard of care for localized disease, including in appropriately selected patients with high risk prostate cancer. Its role has also been expanded to encompass cytoreductive prostatectomy and salvage radical prostatectomy. As surgical expertise grows with robotic assistance, several novel and non-radical approaches have been developed to further mitigate treatment side effects. Patient characteristics, disease factors and surgeon expertise are important metrics for consideration when selecting the most appropriate technique for any given patient.

Undetectable PSA after radical prostatectomy is more likely in low burden N+ prostate cancer patients when an extended lymph node dissection is performed

OBJECTIVES

To analyze the likelihood of undetectable PSA (< 0.01 ng/mL) after extended (ePLND) versus standard pelvic lymph-nodes dissection (sPLND) in pN+ patients.

MATERIALS AND METHODS

The institutional prospectively maintained Prostate Cancer Database was queried for patients who underwent radical prostatectomy with PLND and were found with 3or less lymph-nodal metastases between 2007 and 2017. The extension of the PLND was defined according to the number of lymph-nodes (LN) removed. Patients in the 75th or higher percentile of lymph-nodes removed were considered as the ePLND group; patients in the 25th or lower percentile in the sPLND group. Groups were compared in clinical and pathological variables. Student T-test was used for comparing continuous variables; chi-square test was used for categorical variables. Multivariable logistic regression assessed the probability of undetectable PSA at 3^rd month postoperatively. Kaplan-Meier method estimated the probability of biochemical recurrence. Differences between the groups were compared by Log-rank test.

RESULTS

1478 patients were treated within the time span considered. 95 with 1 to 3 lymph-nodal metastases were extracted. After accounting for inclusion criteria, 23 patients with a median of 11 LN removed were included in the sPLND group (25th percentile); 23 patients with > 27 LN were included in ePLND group (75th percentile). Surgical time was longer for ePLND. Sixteen patients (69.6%) who underwent ePLND had undetectable PSA postoperatively. At multivariable analysis, the probability of undetectable PSA at 3^rd month was higher in patients who received an ePLND (HR=5.18; IC 95%=1.16-23.11; P=.03).

CONCLUSIONS

ePLND is more likely to predict undetectable PSA at third month after radical prostatectomy, irrespective of disease characteristics.

Long-term oncological results of treatment for high-risk prostate cancer using radical prostatectomy in a cancer hospital

OBJECTIVES

To analyse the most relevant oncologic results of treatment using radical prostatectomy (RP) for high-risk prostate cancer (HRPC) in a specialist cancer hospital.

MATERIAL AND METHODS

A descriptive retrospective study of RP was conducted at our centre from 1986 to 2017 on HRPC whose primary objective was to determine overall survival (OS) and cancer-specific survival (CSS). The study's secondary objectives were to determine biochemical progression-free survival (BPFS), metastasis-free survival (MFS), rescue therapy-free survival (RTFS), hormone therapy-free survival (HTFS) and the development of castration-resistant prostate cancer. We performed a Cox regression analysis to establish predictive models and to better understand the weight of each variable that defines high risk.

RESULTS

A total of 2093 RPs were performed, 480 (22.9%) of which were for HRPC. The median follow-up for the overall series was 79.57 months (P_25-75 37.92-135.16). Lymphadenectomy was not performed in 6.5% of the cases. The lymphadenectomy was of the obturator type in 51.2% of the cases and extended in 42.3%. Overall survival at 5, 10 and 15 years was 89.8% (95% CI 86.7-92.9%), 73.3% (95% CI 68-78.6%) and 51.4% (95% CI 43.8-59%), respectively. CSS at 5, 10 and 15 years was 94.8% (95% CI 92.4-97.2%), 84.0% (95% CI 79.3-88.7%) and 75.5% (95% CI 68.8-82.2%), respectively. MFS at 5, 10 and 15 years was 87.4% (95% CI 84.1-90.7%), 72.2% (95% CI 66.7-77.7%) and 61.7% (95% CI 54.3-69.1%), respectively. A total of 120 patients of 477 analysed (25.1%) required rescue radiation therapy, and 293/477 never required hormone therapy (61.4%). Of the 93 pN1 patients, 33 (35.5%) did not require hormone therapy. The time from RP to biochemical progression was the variable with the greatest prognostic weight for MFS, CSS and overall survival.

CONCLUSIONS

RP plus extended lymphadenectomy should be the first therapeutic manoeuvre when feasible within a multimodal strategy. A longer follow-up of the series is needed to validate the hypothesis of better oncologic results based on the earlier implementation of rescue radiation therapy, extended lymphadenectomy and drugs that prolong survival in the CRPC phase.

Sentinel node evaluation in prostate cancer

Sentinel lymph node (SLN) based pelvic lymph node dissection (PLND) in prostate cancer (PCa) is appealing over the time, cost and morbidity classically attributed to conventional PLND during radical prostatectomy. The initial report of feasibility of the SLN concept in prostate cancer was nearly 20 years ago. However, PLND based on the SLN concept, either SLN biopsy of a single node or targeted SLN dissection of multiple nodes, is still considered investigational in PCa. To better appreciate the challenges, and potential solutions, associated with SLN-based PLND in PCa, this review will discuss the rationale behind PLND in PCa and evaluate current SLN efforts in the most commonly diagnosed malignancy in men in the US.

A practical guide for the use of indocyanine green and methylene blue in fluorescence-guided abdominal surgery

Near-infrared (NIR) fluorescence imaging is gaining clinical acceptance over the last years and has been used for detection of lymph nodes, several tumor types, vital structures and tissue perfusion. This review focuses on NIR fluorescence imaging with indocyanine green and methylene blue for different clinical applications in abdominal surgery with an emphasis on oncology, based on a systematic literature search. Furthermore, practical information on doses, injection times, and intraoperative use are provided.

Fluorescence-supported lymphography and extended pelvic lymph node dissection in robot-assisted radical prostatectomy: a prospective, randomized trial

PURPOSE

To demonstrate the benefits of fluorescence-supported extended pelvic lymph node dissection (ePLND) compared to regular ePLND in robot-assisted radical prostatectomy.

METHODS

120 patients with intermediate- or high-risk prostate cancer were prospectively randomized (1:1): in the intervention group, indocyanine green (ICG) was injected transrectally into the prostate before docking of the robot. In both groups, ePLND was performed including additional dissection of fluorescent lymph nodes (LN) in the ICG group.

RESULTS

After drop-out of two patients, 59 patients were allocated to the control (A) and intervention group (B) with a median PSA of 8,6 ng/ml. Median console time was 159 (A) vs. 168 (B) min (p = 0.20) with a longer time for ICG-ePLND: 43 (A) vs. 55 min (B) (p = 0.001). 2609 LN were found with significantly more LN after ICG-supported ePLND with a median of 25 vs. 17 LN in A (p < 0.001). Nodal metastases were detected in 6 patients in A (25 cancerous LN) vs. 9 patients in B (62 positive LN) (p = 0.40). In seven of nine patients, ICG-ePLND identified at least one cancer-positive LN (sensitivity 78%), 27 of 62 cancerous LN were fluorescent. Symptomatic lymphocele occurred in one patient in a and in three patients in b (p = 0.62). After a median follow-up of 22.9 months, PSA levels were similar.

CONCLUSIONS

While ICG-ePLND seems to be beneficial for a better understanding of the lymphatic drainage and a more meticulous diagnostic approach, the sensitivity is not sufficient to recommend stand-alone ICG lymph node dissection.

Anatomical localization and clinical impact of sentinel lymph nodes based on patterns of pelvic lymphatic drainage in clinically localized prostate cancer

BACKGROUND

Although sentinel lymph node in prostate has been generating renewed interest, its significance remains controversial due to inadequate evidence.

METHODS

We reviewed a prospective cohort of 50 consecutive patients with intermediate- to high-risk localized prostate cancer who had undergone laparoscopic radical prostatectomy. Sentinel lymph node biopsy by fluorescence detection using intraoperative imaging with indocyanine green and backup extended pelvic lymph node dissection were conducted prior to prostatectomy. Intraoperative and pathological findings were elaborated and compared for confirmation.

RESULTS

Sentinel lymph nodes were successfully identified in 47 patients (94%). A median of four sentinel lymph nodes was detected per patient. Lymph node metastasis was confirmed in six patients (12%), all of whom had positive sentinel lymph nodes. Three typical pathways of lymphatic drainage related to sentinel lymph nodes from the prostate were recognized. Ninety-one percent of the positive sentinel lymph nodes (10/11) were located at two predominant sites along these characteristic lymphatic pathways. One site was the junctional nodes, located at the junction between internal and external iliac vessels. The other was the distal internal iliac nodes, located along the inferior vesical artery.

CONCLUSIONS

Over 90% of positive sentinel lymph nodes were identified at two predominant sites. Priority should be given to the removal of these sentinel lymph nodes, which are located closer to the prostate, in pelvic lymph node dissection. Particular attention should be paid to identifying these nodes to reduce the possibility of overlooking lymph node metastasis.

Near-infrared Intraoperative Molecular Imaging Can Identify Metastatic Lymph Nodes in Prostate Cancer

OBJECTIVE

To propose a novel method to perform indocyanine green (ICG) based near-infrared (NIR) fluorescence imaging during pelvic lymph node dissection (PLND) for prostate cancer patients with lymph node metastasis (LNM).

MATERIALS AND METHODS

A prostate cancer cell line PC3 was used to establish xenograft model in NOD/SCID mice. After tumor growth, the mice were injected with ICG through the tail vein. Xenografts and surrounding tissues were imaged with NIR camera 24 hours after intravenous ICG, and tumor-to-background ratios were calculated. We then performed a pilot human study to evaluate the role of NIR imaging in robotic PLND after systemic ICG in 4 patients with prostate cancer and preoperative lymphadenopathy.

RESULTS

ICG localized to PC3 xenografts in the mice and all xenografts were highly fluorescent compared with surrounding tissues, with a median tumor-to-background ratio of 2.85 (interquartile range = 2.64-3.90). In the human study, intraoperative in vivo NIR imaging identified 3 of the 4 preoperative lymphadenopathies as fluorescence-positive, and back table ex vivo NIR imaging identified all 4 lymphadenopathies as fluorescence-positive. All the lymphadenopathies were found to be LNMs by pathologic examination. Two of the four cases had additional LNMs, all of which were fluorescence-positive with intraoperative in vivo NIR imaging.

CONCLUSION

Intravenously administered ICG accumulates in prostate cancers in both a murine model and human patients. NIR fluorescence based on intravenous ICG may serve as a useful tool to facilitate the identification of positive nodes during PLND in patients with higher risk of LNMs.