Lymphatic Drainage from Renal Cell Carcinoma along the Thoracic Duct Visualized with SPECT/CT

The Current Role of Lymph Node Dissection in Nonmetastatic Localized Renal Cell Carcinoma

PURPOSE

To explore the current role of lymph node dissection (LND) in the management of nonmetastatic localized renal cell carcinoma (RCC).

BACKGROUND

There is currently no proven benefit of LND in the setting of RCC, and its role remains controversial because of conflicting evidence. Patients who may benefit from LND are those at greatest risk of nodal disease, but the tools used to predict nodal involvement are limited due to unpredictable retroperitoneal lymphatics. The indications, templates, and extent of LND are also not standardized, adding to the ambiguity of current guidelines surrounding its use.

EVIDENCE ACQUISITION

A PubMed search of the literature from January 2017 to December 2022 was conducted using the search terms "renal cell carcinoma" or "renal cancer" in combination with "lymph node dissection" or "lymphadenectomy". Case studies and editorials were excluded, whereas studies investigating the therapeutic effect of LND were classified as either demonstrating a benefit or no benefit. References of the studies and review articles were also searched for notable studies and findings that were outside the five-year literature search. The studies in this review were restricted to the English language.

RESULTS

Only a number of studies in recent years have found an association between the extent of LND and increased survival. Most studies do not indicate an associated benefit, and some even suggest a negative effect on survival. Most of these studies are retrospective.

CONCLUSION

The therapeutic value of LND in RCC is still unclear, and although prospective data are needed, its declining rates and emerging new therapies make this unlikely. A better understanding of renal lymphatics and improved detection of nodal disease may help determine the role of LND in nonmetastatic localized RCC.

Integrating Surgery in the Multidisciplinary Care of Advanced Renal Cell Carcinoma

The role of surgery for patients with locally advanced and metastatic renal cell carcinoma (RCC) is not precisely defined in our contemporary era of systemic therapies. Research in this field is focused on the role of regional lymphadenectomy, along with indications and timing of cytoreductive nephrectomy and metastasectomy. As our understanding of the molecular and immunological basis of RCC continues to develop along with the advent of novel systemic therapies, prospective clinical trials will be critical in defining how surgery should be integrated into the treatment paradigm of advanced RCC.

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.

Nanomedicine for renal cell carcinoma: imaging, treatment and beyond

The kidney is a vital organ responsible for maintaining homeostasis in the human body. However, renal cell carcinoma (RCC) is a common malignancy of the urinary system and represents a serious threat to human health. Although the overall survival of RCC has improved substantially with the development of cancer diagnosis and management, there are various reasons for treatment failure. Firstly, without any readily available biomarkers, timely diagnosis has been greatly hampered. Secondly, the imaging appearance also varies greatly, and its early detection often remains difficult. Thirdly, chemotherapy has been validated as unavailable for treating renal cancer in the clinic due to its intrinsic drug resistance. Concomitant with the progress of nanotechnological methods in pharmaceuticals, the management of kidney cancer has undergone a transformation in the recent decade. Nanotechnology has shown many advantages over widely used traditional methods, leading to broad biomedical applications ranging from drug delivery, prevention, diagnosis to treatment. This review focuses on nanotechnologies in RCC management and further discusses their biomedical translation with the aim of identifying the most promising nanomedicines for clinical needs. As our understanding of nanotechnologies continues to grow, more opportunities to improve the management of renal cancer are expected to emerge.

To Be or "Node" to Be: Nodal Disease and the Role of Lymphadenectomy in the Treatment of Renal Cell Carcinoma

Lymph node involvement in renal cell carcinoma (RCC) correlates with poor oncologic outcomes. However, current RCC staging guidelines may not fully reflect the survival impact of lymph node positive disease. Recent data demonstrates that nodal disease has significant impact on survival and modifications to current staging guidelines have been proposed. Lymph node dissection (LND) at the time of surgical intervention for RCC remains controversial. While clinical trial data have demonstrated conflicting evidence for LND, some institutional studies suggests that carefully selected patients at high-risk for recurrence may benefit from LND. Prospectively, clinical trials are examining treating nodal disease and disease at high-risk of recurrence in the neoadjuvant and/or adjuvant setting at the time of nephrectomy. These promising trials are poised, if successful, to influence the treatment paradigm for localized RCC.

An analysis of SPECT/CT non-visualization of sentinel lymph nodes in renal tumors

Background

Sentinel lymph node biopsy (SLNB) after intratumoral injection of ^99mTc labeled nanocolloid and imaging with scintigraphy and SPECT/CT in renal tumors is feasible. However, sentinel lymph node (SN) non-detection rate with scintigraphy and SPECT/CT is high. The aim of the study was to determine factors affecting non-visualization (NV) of SN imaging in renal tumors. Seventy-eight patients with cT1–3 renal tumors received intratumoral injection of 225 MBq ^99mTc-labeled nanocolloid 1 day before (partial) nephrectomy. Radiotracer injection was followed by anterioposterior and lateral scintigraphy in combination with SPECT/CT 20 min and 2–4 h after. Surgical treatment of the tumor with sentinel lymph node biopsy by aid of γ-probe and-camera was performed the next day. Scintigraphy and SPECT/CT images were evaluated and patient, tumor, and procedure characteristics were collected for 73 eligible patients used in uni- and multivariable analysis of a potential association with NV.

Results

A total of 80 (mean 1.1, IQR 0–2, max 6) sentinel lymph nodes in 46 patients were detected with scintigraphy and SPECT/CT. Preoperative visualization rate and intraoperative detection rate was 63% [95% CI 50–73%] and 61% [95% CI 49–72%], respectively. In uni- and multivariable analysis, the only factor associated with non-visualization was age, showing higher odds of non-visualization with higher age.

Conclusion

Our study demonstrated that non-visualization of SNs in renal tumors is relatively high and is associated with patient age. Furthermore, kidneys and also its tumors are highly vascularized which may cause a wash-out effect that could be identified with decreased kidney-liver ratios. However, in our data, the effect was statistically inconclusive. Further studies are needed to improve visualization and standardize the procedure of SLNB in renal tumors. The percentage of NV limits the use of SLNB for research and clinical purposes in renal cancer.

Electronic supplementary material

The online version of this article (10.1186/s13550-018-0460-y) contains supplementary material, which is available to authorized users.

The side and the location of the primary tumor does not affect the probability of lymph node invasion in patients with renal cell carcinoma

PURPOSE

To evaluate the role of side and location of the primary renal cell carcinoma (RCC) on the risk of lymph node invasion (LNI) and/or nodal progression (NP) during follow-up.

MATERIALS AND METHODS

We evaluated 2485 patients with unilateral RCC, surgically treated in a single tertiary care referral center. Outcomes were LNI at surgery and/or NP during follow-up. We studied if RCC side (left vs. right) and location (upper vs. middle vs. hilar vs. lower area vs. more than one area) affected the probability of LNI and/or NP at follow-up.

RESULTS

Overall, 43 and 15% of patients underwent lymph node dissection and had LNI at surgery, respectively. During follow-up, 2.2% of patients had NP. Higher rates of LNI and NP were observed for patients with primary tumor located in more than one anatomical kidney area relative to patients with tumor in a single area (upper 11% vs. middle 10% vs. hilar 0%, vs. lower 12% vs. more than one area 26%, p < 0.01). cM1, cN1, pT2/pT3/pT4 disease and Fuhrman grade 3/4 were independent predictors of the study outcome (all p ≤ 0.01). Neither the RCC side nor the location reached the independent predictor status (all p > 0.1).

CONCLUSIONS

Patients with single-side and more than one anatomical kidney area affected by RCC have higher rate of LNI at surgery and/or NP at follow-up. Neither side nor location of primary RCC tumor is related to the risk of harboring LNI at surgery and/or developing NP at follow-up.

The Effect of Anatomical Location of Lymph Node Metastases on Cancer Specific Survival in Patients with Clear Cell Renal Cell Carcinoma

Background

Positive nodal status (pN1) is an independent predictor of survival in renal cell carcinoma (RCC) patients. However, no study to date has tested whether the location of lymph node (LN) metastases does affect oncologic outcomes in a population submitted to radical nephrectomy (RN) and extended lymph node dissection (eLND).

Objective

To describe nodal disease dissemination in clear cell RCC (ccRCC) patients and to assess the effect of the anatomical sites and the number of nodal areas affected on cancer specific mortality (CSM).

Design, setting and partecipants

The study included 415 patients who underwent RN and eLND, defined as the removal of hilar, side-specific (pre/paraaortic or pre/paracaval) and interaortocaval LNs for ccRCC, at two institutions.

Outcome measurement and statistical analysis

Descriptive statistics were used to depict nodal dissemination in pN1 patients, stratified according to nodal site and number of involved areas. Multivariable Cox regression analyses and Kaplan-Meier curves were used to explore the relationship between pN1 disease features and survival outcomes.

Results and limitations

Median number of removed LN was 14 (IQR 9–19); 23% of patients were pN1. Among patients with one involved nodal site, 54 and 26% of patients were positive only in side-specific and interaortocaval station, respectively. The most frequent nodal site was the interaortocaval and side-specific one, for right and left ccRCC, respectively. Interaortocaval nodal positivity (HR 2.3, CI 95%: 1.3–3.9, p < 0.01) represented an independent predictor of CSM.

Conclusions

When ccRCC patient harbour nodal disease, its spreading can occur at any nodal station without involving the others. The presence of interoartocaval positive nodes does affect oncologic outcomes.

Patient summary

Lymph node invasion in patients with clear cell renal cell carcinoma is not following a fixed anatomical pattern. An extended lymph node dissection, during treatment for primary kidney tumour, would aid patient risk stratification and multimodality upfront treatment.

Lymphatic Drainage from Renal Tumors In Vivo: A Prospective Sentinel Node Study Using SPECT/CT Imaging

PURPOSE

Lymphatic drainage from renal tumors is unpredictable. In vivo drainage studies of primary lymphatic landing sites may reveal the variability and dynamics of lymphatic connections. The purpose of this study was to investigate the lymphatic drainage pattern of renal tumors in vivo with single photon emission/computerized tomography after intratumor radiotracer injection.

MATERIALS AND METHODS

We performed a phase II, prospective, single arm study to investigate the distribution of sentinel nodes from renal tumors on single photon emission/computerized tomography. Patients with cT1-3 (less than 10 cm) cN0M0 renal tumors of any subtype were enrolled in analysis. After intratumor ultrasound guided injection of 0.4 ml ^99mTc-nanocolloid we performed preoperative imaging of sentinel nodes with lymphoscintigraphy and single photon emission/computerized tomography. Sentinel and locoregional nonsentinel nodes were resected with a γ probe combined with a mobile γ camera. The primary study end point was the location of sentinel nodes outside the locoregional retroperitoneal templates on single photon emission/computerized tomography. Using a Simon minimax 2-stage design to detect a 25% extralocoregional retroperitoneal template location of sentinel nodes on imaging at α = 0.05 and 80% power at least 40 patients with sentinel node imaging on single photon emission/computerized tomography were needed.

RESULTS

Of the 68 patients 40 underwent preoperative single photon emission/computerized tomography of sentinel nodes and were included in primary end point analysis. Lymphatic drainage outside the locoregional retroperitoneal templates was observed in 14 patients (35%). Eight patients (20%) had supradiaphragmatic sentinel nodes.

CONCLUSIONS

Sentinel nodes from renal tumors were mainly located in the respective locoregional retroperitoneal templates. Simultaneous sentinel nodes were located outside the suggested lymph node dissection templates, including supradiaphragmatic sentinel nodes in more than a third of the patients.

Lymph node dissection should not be dismissed in case of localized renal cell carcinoma in the presence of larger diseases

OBJECTIVE

To assess whether even in the group of localized renal cell carcinoma (RCC), some patients might harbor a disease with a predilection for lymph node invasion (LNI) and/or lymph node (LN) progression and might deserve lymph node dissection (LND) at the time of surgery.

MATERIALS AND METHODS

Between 1990 and 2014, 2,010 patients with clinically defined T1-T2N0M0 RCC were treated with nephrectomy and standardized LND at a single tertiary care referral center. The endpoint consists of the presence of LNI and/or nodal progression, defined as the onset of a new clinically detected lymphadenopathy (>10mm) in the retroperitoneal lymphatic area with associated systemic progression or histological confirmation or both. We tested the association between clinical characteristics and the endpoint of interest. Predictors consisted of age at surgery, clinical tumor size, preoperative hemoglobin, and platelets levels. Multivariable logistic regression model and smoothed Lowess method were used.

RESULTS

LNI was recorded in 14 cases (2.2%). The median follow-up after surgery was 68 months. During the study period, 23 patients (1.1%) experienced LN progression; 91% of those patients experienced LN progression within 3 years after surgery. Combining the 2 endpoints, 36 patients (1.8%) had LNI and/or LN progression. Clinical tumor size was the only independent predictors of LNI and/or LN progression (OR = 1.25). A significant increase of the risk of LNI and/or LN progression was observed in RCC larger than 7cm (cT2a or higher).

CONCLUSIONS

LNI and/or LN progression is a rare entity in patients with localized RCC. Nonetheless, patients with larger tumors might still benefit from LND because of a non-negligible risk of LNI and/or LN progression.

Beyond penile cancer, is there a role for sentinel node biopsy in urological malignancies?

This review aims to discuss the current state-of-the-art of sentinel node (SN) mapping in urological malignancies. The principles and methodological aspects of lymphatic mapping and SN biopsy in urological malignancies are reviewed. Literature search was restricted to English language. The references of the retrieved articles were examined to identify additional articles. The review also includes meta-analyses published in the past 5 years. SN biopsy for penile cancer is recommended by the European Association of Urology as the preferred staging tool for clinically node-negative patients with at least T1G2 tumours (level of evidence 2a, Grade B). The feasibility of SN biopsy in prostate cancer has been repeatedly demonstrated and its potential value is increasingly being recognised. However, conclusive prospective clinical data as well as consensus on methodology and patient selection are still lacking. For bladder, renal and testicular cancer, only few studies have been published, and concerns around high false-negative rates remain. Throughout the years, the uro-oncological field has portrayed a pivotal role in the development of the SN concept. Recent advances such as hybrid tracers and novel intraoperative detection tools such as fluorescence and portable gamma imaging will hopefully encourage prospectively designed clinical trials which can further substantiate the potential of the SN approach in becoming an integral part of staging in urological malignancies beyond penile cancer.

Lymphatic drainage in renal cell carcinoma: back to the basics

Lymphatic drainage in renal cell carcinoma (RCC) is unpredictable, however, basic patterns can be observed in cadaveric and sentinel lymph node mapping studies in patients with RCC. The existence of peripheral lymphovenous communications at the level of the renal vein has been shown in mammals but remains unknown in humans. The sentinel lymph node biopsy technique can be safely applied to map lymphatic drainage patterns in patients with RCC. Further standardisation of sentinel node biopsy techniques is required to improve the clinical significance of mapping studies. Understanding lymphatic drainage in RCC may lead to an evidence-based consensus on the surgical management of retroperitoneal lymph nodes.