Investigating the role of SPECT/CT in dynamic sentinel lymph node biopsy for penile cancers

New EAU/ASCO guideline recommendations on sentinel node biopsy for penile cancer and remaining challenges from a nuclear medicine perspective

INTRODUCTION

The European Association of Urology (EAU) and the American Society of Clinical Oncology (ASCO) recently issued updated guidelines on penile cancer, emphasising dynamic sentinel node biopsy (DSNB) as the preferred method for surgical staging among patients with invasive penile tumours and no palpable inguinal lymphadenopathy. This paper outlines the rationale behind this new recommendation and describes remaining challenges, as well as strategies for promoting DSNB worldwide.

MAIN TEXT

DSNB offers high diagnostic accuracy with the lowest postoperative complications compared to open or minimally invasive inguinal lymph node dissection (ILND), prompting its preference in the new guidelines. Nevertheless, despite its advantages, there are challenges hampering the widespread adoption of DSNB. This includes the false-negative rate associated with DSNB and the potential negative impact on patient outcome. To address this issue, improvements should be made in several areas, including refining the timing and interpretation of the lymphoscintigraphy and the single photon emission computed tomography/computed tomography images. In addition, the quantity of tracer employed and choice of the injection site for the radiopharmaceutical should be optimised. Finally, limiting the removal of nodes without tracer activity during surgery may help minimise complication rates.

CONCLUSION

Over the years, DSNB has evolved significantly, related to the dedicated efforts and innovations in nuclear medicine and subsequent clinical studies validating its efficacy. It is now strongly recommended for surgical staging among selected penile cancer patients. To optimise DSNB further, multidisciplinary collaborative research is required to improve SN identification for better diagnostic accuracy and fewer complications.

Combined Doxorubicin Mesoporous Carbon Nanospheres for Effective Tumor Lymphatic Metastasis by Multi-Modal Chemo-Photothermal Treatment in vivo

Introduction

Sentinel lymph node (SLN) is the first regional lymph node where tumor cells metastasize, and its identification and treatment are of great significance for the prevention of tumor metastasis. However, the current clinical modalities for identification and treatment of SLN are still far from satisfactory owing to their high cost, invasiveness and low accuracy. We aim to design a novel nanomedicine system for SLN imaging and treatment with high efficacy.

Methods

We designed and prepared hollow mesoporous carbon spheres (HMCS) and loaded with the chemotherapeutic drug doxorubicin (DOX), which is then modified with polyvinyl pyrrolidone (PVP) to obtain nanomedicine: HMCS-PVP-DOX.

Results

HMCS-PVP with a size of about 150 nm could retain in the lymph nodes for a long time and stain the lymph nodes, which could be easily observed by the naked eye. At the same time, HMCS-PVP exhibited excellent photoacoustic and photothermal imaging capabilities, realizing multimodal imaging to locate lymph nodes precisely. Due to its high specific surface area, HMCS could be largely loaded with the chemotherapeutic drug doxorubicin (DOX). HMCS-PVP-DOX displayed highly efficient synergistic chemotherapy-photothermal therapy for lymphatic metastases in both cellular and animal experiments due to its significant photothermal effect under 1064 nm laser irradiation. HMCS-PVP-DOX also displayed great stability and biosafety.

Discussion

Multifunctional nanomedicine HMCS-PVP-DOX is expected to provide a novel paradigm for designing nanomedicine to the diagnosis and treatment of lymphatic metastases because of its good stability and safety.

Accuracy of dynamic sentinel lymph node biopsy for inguinal lymph node staging in cN0 penile cancer

BACKGROUND

Penile cancer is characterized by an early lymphatic dissemination. In intermediate and high-risk primary tumors without palpable inguinal lymph nodes, there is a 6-30% risk of micro-metastatic disease. Invasive lymph node staging in these patients is performed using dynamic sentinel lymph node biopsy (DSNB). In this study, the role of DSNB in cN0 penile cancer was studied, evaluating features of sentinel lymph node (SN) visualization and outcome parameters. Patients with penile cancer without inguinal lymph node metastases who were referred for DSNB at our center between January 2015 and May 2021 and had a follow-up period of at least 18 months, were retrospectively included. After injection of 85 ± 20 MBq [^99mTc]Tc-nanocolloid peritumorally, dynamic, static planar and SPECT/CT imaging was performed. Primary endpoints were sensitivity of the diagnostic procedure, disease-free survival and DSNB-related adverse events. Secondary endpoints were SN detection rate, number of SNs and the number of counts of the most active SN.

RESULTS

Seventy-seven penile DSNB procedures in 75 patients (67 ± 11 years) were included. The detection rate of DSNB was 91% and 96% per procedure and groin, respectively. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 79%, 100%, 97% and 100%, respectively. More SNs were seen on SPECT/CT than on static planar imaging (1.33 vs. 1.17, p = 0.001). The mean counts per SN on static planar imaging was lower compared to SPECT/CT (1343 vs. 5008; p < 0.0001). There was a positive correlation between the total counts of the SN on the static planar image and the SPECT/CT (r = 0.79, p < 0.0001). Only one out of seventy-five patients (1%) experienced DSNB-related adverse events. After 18 months, 58 patients remained disease free (77%), 13 developed local recurrence (17%), and 4 developed lymphatic or distant metastases (5%).

CONCLUSION

DNSB is a safe diagnostic procedure with a good detection rate and in particular high negative predictive value. It can therefore prevent overtreatment of patients with negative inguinal groins on clinical examination and DSNB examination. Finally, DSNB enables an early detection of occult metastases which would not be visualized with standardized imaging modalities.

The Sentinel Lymph Node in Treatment Planning: A Narrative Review of Lymph-Flow-Guided Radiotherapy

The sentinel lymph node technique is minimally invasive and used routinely by surgeons, reducing the need for morbid extensive lymph node dissections, which is a significant advantage for cancer staging and treatment decisions. The sentinel lymph node could also help radiation oncologists to identify tumor drainage for each of their patients, leading to a more personalized radiotherapy, instead of a probabilistic irradiation based on delineation atlases. The aim is both to avoid recurrence in unexpected areas and to limit the volume of irradiated healthy tissues. The aim of our study is to evaluate the impact of sentinel lymph node mapping for radiation oncologists. This concept, relying on sentinel lymph node mapping for treatment planning, is known as lymph-flow-guided radiotherapy. We present an up-to-date narrative literature review showing the potential applications of the sentinel lymph node technique for radiotherapy, as well as the limits that need to be addressed before its routine usage.

Sentinel Node Identification with Hybrid Tracer-guided and Conventional Dynamic Sentinel Node Biopsy in Penile Cancer: A Prospective Study in 130 Patients from the Two National Referral Centres in Sweden

BACKGROUND

Studies suggest that a hybrid indocyanine green (ICG)-^99mTc-nanocolloid tracer improves sentinel node (SN) identification compared to conventional dynamic sentinel node biopsy (DSNB).

OBJECTIVE

To investigate hybrid tracer-guided SN identification in a multicentre setting and determine false-negative (FN) and complication rates.

DESIGN, SETTING, AND PARTICIPANTS

A total of 130 patients with penile cancer scheduled for DSNB were prospectively included between February 2016 and December 2017 at two national Swedish referral centres. ICG-^99mTc-nanocolloid hybrid tracer was used in the standard DSNB protocol.

INTERVENTION

SNs were identified intraoperatively using radioguidance, fluorescence imaging, and blue dye.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The number of SNs identified by each tracer and the rates of complications and nodal recurrence during median follow-up of 34 mo were recorded. Differences in proportions between groups were compared using χ² and McNemar's tests.

RESULTS AND LIMITATIONS

Overall, 453 SNs were identified preoperatively via single-photon emission computed tomography/computed tomography. Among the 425 SNs excised, radioguidance, fluorescence, and blue dye identified 414 (97%), 363 (85%), and 349 (82%), respectively. Fluorescence imaging helped to detect six SNs that were negative using the other tracers, two of which were from the same patient and contained metastases. Histopathological examination detected 33 metastatic SNs in 20/130 patients (15%). The FN rate was 12% per groin (95% confidence interval 8-16%).

CONCLUSIONS

Identification of SNs in patients with penile cancer relies mainly on radioguidance, while fluorescence (ICG) and blue dye methods for optical SN identification are comparable. However, the value of fluorescence imaging should be further evaluated in studies with long-term follow-up.

PATIENT SUMMARY

In this study, we investigated addition of a dye called indocyanine green (ICG) for assessment of lymph nodes in patients with cancer of the penis. ICG did not improve the rate of detection of nodes most likely to harbour cancer because of their location in the drainage pathway for lymphatic fluid, but did help in identifying additional metastases.

Minimally invasive evaluation of the clinically negative inguinal node in penile cancer: Dynamic sentinel node biopsy

The presence of lymph node metastasis is the most important prognostic factor in penile cancer (PeCa). Due to limited sensitivity of currently available imaging modalities, invasive staging approaches remain indispensable for adequate nodal staging. As an alternative to radical inguinal lymphadenectomy and with the aim to reduce morbidity, staging strategies such as modified lymphadenectomy and dynamic sentinel node biopsy (DSNB) have been introduced. Over the years, DSNB evolved into a safe and reliable staging technique when performed in high volume centers. Recent enhancements of the procedure such as Single-photon emission computed tomography/computed tomography (SPECT/CT) and the introduction of hybrid tracers have improved pre- and intraoperative sentinel node (SN) visualization. Other technologies such as superparamagnetic iron oxide nanoparticles could have a potential future role to further refine DSNB. Future efforts should be aimed at optimizing diagnostic accuracy whilst minimizing perioperative morbidity.

Interrogating the Impassable: A Case Series and Literature Review of Unilateral SPECT-CT Groin Visualization in Men With Penile Cancer

Penile squamous cell carcinoma (SCC) is a rare malignancy, which is known to invade local inguinal lymph nodes prior to progressing to the pelvis. Dynamic sentinel lymph node biopsy (DSLNB) is a standard for the minimally invasive assessment of lymphadenopathy in patients with subclinical groin metastasis. Hybrid ^99mTc Single-Photon Emission Computed Tomography (SPECT-CT) has been shown to increase the accuracy of identifying first draining “sentinel” nodes (SN). Unilateral inguinal visualization on SPECT-CT is a rare presentation, which may increase the likelihood of a false negative SN biopsy. Retrospective analysis from three-penile cancer uro-oncologists in Melbourne, Australia identified 78 groins undergoing DSLNB for intermediate/high risk primary disease. Unilateral SPECT-CT results were observed in four patients suggesting a functional pattern of lymph diversion. Analysis confirmed malignancy (n = 2), sarcoidosis (n = 1), and evidence of local inflammation in SPECT-CT negative groins. Findings re-iterate the role of SPECT-CT a pre-operative adjunct. Experienced multimodal groin assessment using palpation, SPECT-CT, lymphoscintigraphy, and blue dye tracking remains paramount. Unilateral SN on pre-operative SPECT-CT in men with intermediate/high-risk penile SCC should elicit a higher degree of clinical suspicion. We recommend a low threshold for recommending radical inguinal lymph node dissection (ILND) for groins refractory to minimally invasive assessment.

Methods of Sentinel Lymph Node Identification in Auricular Melanoma

Sentinel lymph node biopsy is used to evaluate for micrometastasis in auricular melanoma. However, lymphatic drainage patterns of the ear are not well defined and predicting the location of sentinel nodes can be difficult. The goal of this study was to define the lymphatic drainage patterns of the ear and to compare multiple modalities of sentinel node identification.

METHODS

A retrospective review of a prospectively maintained database evaluated 80 patients with auricular melanoma who underwent sentinel lymph node biopsy by comparing preoperative imaging with intraoperative identification of sentinel nodes. Patients were placed into two cohorts, based on the modality of preoperative imaging: (1) planar lymphoscintigraphy only (n = 63) and (2) single-photon emission computerized tomography combined with computerized tomography (SPECT-CT) only (n = 17). Sites of preoperative mapping and sites of intraoperative identification were recorded as parotid/preauricular, mastoid/postauricular, and/or cervical.

RESULTS

In patients that underwent planar lymphoscintigraphy preoperatively (n = 63), significantly more sentinel nodes were identified intraoperatively than were mapped preoperatively in both the parotid/preauricular (P = 0.0017) and mastoid/postauricular (P = 0.0047) regions. Thirty-two nodes were identified intraoperatively that were not mapped preoperatively in the planar lymphoscintigraphy group (n = 63), two of which were positive for micrometastatic disease. In contrast, there were no discrepancies between preoperative mapping and intraoperative identification of sentinel nodes in the SPECT-CT group (n = 17).

CONCLUSIONS

SPECT-CT is more accurate than planar lymphoscintigraphy for the preoperative identification of draining sentinel lymph nodes in auricular melanoma. If SPECT-CT is not available, planar lymphoscintigraphy can also be used safely, but careful intraoperative evaluation, even in basins not mapped by lymphoscintigraphy, must be performed to avoid missed sentinel nodes.

Repeat injection following sentinel node nonvisualization on lymphoscintigraphy images can decrease axillary dissection rate in breast cancer patients

AIM

Sentinel node biopsy is considered the standard of care in early-stage breast cancer patients. In the current study, we evaluated the effect of radiotracer reinjection in the case of sentinel node nonvisualization on preoperative lymphoscintigraphy.

MATERIALS AND METHODS

Between March 2017 and March 2020, 1850 early-stage breast cancer patients were referred for sentinel node mapping. All patients received a single injected activity of Tc-99m Phytate intradermally in the periareolar area of the index lesion using an insulin syringe. Lymphoscintigraphy images of the patients were done 1-2 h postinjection. Between March 2017 and September 2017, sentinel node nonvisualization was reported to the surgeon, and for the rest of the study period, the patients received another injected activity of the radiotracer, and immediately, other lymphoscintigraphy images were taken (with the same parameters).

RESULTS

A total of 255 patients entered our study. Fifty-five patients were in group I without any reinjection. The remainder of the patients were in group II. In 155 out of 200 patients of group II, a sentinel node could be visualized following reinjection of the radiotracer. The detection rate was 15 out of 45 and 15 out of 55 in group I and patients without sentinel node visualization even after reinjection, respectively. Axilla was involved in 5 out of 40 (12.5%) patients in group I with intraoperative sentinel node mapping failure. On the other hand, axilla was involved in 27 out of 30 (90%) group II patients with sentinel node nonvisualization.

CONCLUSION

Reinjection of the tracer in cases of no sentinel node visualization in lymphoscintigraphy for breast cancer increases the detection rate of sentinel nodes, and therefore a high number of unnecessary axillary lymph node dissections can be avoided.

Imaging technology of the lymphatic system

The lymphatic system plays critical roles in tissue fluid homeostasis and immunity and has been implicated in the development of many different pathologies, ranging from lymphedema, the spread of cancer to chronic inflammation. In this review, we first summarize the state-of-the-art of lymphatic imaging in the clinic and the advantages and disadvantages of these existing techniques. We then detail recent progress on imaging technology, including advancements in tracer design and injection methods, that have allowed visualization of lymphatic vessels with excellent spatial and temporal resolution in preclinical models. Finally, we describe the different approaches to quantifying lymphatic function that are being developed and discuss some emerging topics for lymphatic imaging in the clinic. Continued advancements in lymphatic imaging technology will be critical for the optimization of diagnostic methods for lymphatic disorders and the evaluation of novel therapies targeting the lymphatic system.

Progress on Management of Penile Cancer in 2020

OPINION STATEMENT

Management of penile cancer represents a challenge to urologic oncologists due to the disease's rarity and sparse data in the literature. Squamous cell carcinoma represents the most common histologic subtype of penile cancer. Penile cancer has a disastrous effect on patients' psychological and physical health. Penile cancer accounts for approximately 1% of cancer deaths in the USA annually. However, in recent years, the management of penile cancer has achieved marked progress in both diagnostic and therapeutic approaches with the intent to avoid radical surgeries. The traditional total penile amputation has been replaced by penile preserving procedures in many patients. Nowadays, total penile amputation (total penectomy) is preserved only for patients with proximal lesions. The introduction of minimally invasive surgical techniques in the management of penile cancer-infiltrated lymph nodes has been reported. Given the dismal prognosis with conventional cytotoxic therapies, new systemic therapies have been investigated in patients with locally advanced or metastatic penile cancer. Multiple studies have shown promising outcomes. All these efforts have resulted in a remarkable improvement in patient quality of life. The objectives of our review are to update clinicians on the advances in the management of penile cancer and to summarize the recent guidelines and recommendations.

Hybrid Indocyanine Green-99mTc-nanocolloid for Single-photon Emission Computed Tomography and Combined Radio- and Fluorescence-guided Sentinel Node Biopsy in Penile Cancer: Results of 740 Inguinal Basins Assessed at a Single Institution

BACKGROUND

Sentinel node (SN) biopsy in penile cancer (PeCa) is typically performed using ^99mTc-nanocolloid and blue dye. Recent reports suggested that the hybrid (radioactive and fluorescent) tracer indocyanine green (ICG)-^99mTc-nanocolloid may improve intraoperative optical SN identification.

OBJECTIVE

The current study aimed to confirm the reliability of ICG-^99mTc-nanocolloid and to assess whether blue dye is still of added value.

DESIGN, SETTING, AND PARTICIPANTS

A total of 400 ≥T1G2N0 PeCa patients were staged with SN biopsy at a single European centre. SNs were preoperatively identified with lymphoscintigraphy and single-photon emission computed tomography. Intraoperatively, SNs were detected via gamma tracing, blue staining, and fluorescence imaging.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

All patients (n=400, 740 groins) received ICG-^99mTc-nanocolloid. Intraoperative SN identification rates were retrospectively evaluated. In those patients who received ICG-^99mTc-nanocolloid and blue dye (n=266, 492 groins), SN visualisation rates were compared using the McNemar test.

RESULTS AND LIMITATIONS

In total, 740 groins were assessed. No tracer-related (allergic) reactions were reported. All preoperatively defined SNs (n=1163) were localised intraoperatively. Of all excised SNs, 98% were detectable with gamma probe and 96% were visible with fluorescence imaging. In the analysis of the patients who received ICG-^99mTc-nanocolloid and blue dye, fluorescence imaging yielded a 39% higher SN detection rate than blue dye (95% confidence interval 36-43%, p<0.001). Of the SNs that were tumour positive, 100% were intraoperatively visualised by fluorescence imaging, whereas merely 84% of the positive nodes stained blue.

CONCLUSIONS

This study confirms that ICG-^99mTc-nanocolloid is a reliable SN tracer for PeCa that significantly improves optical SN detection over blue dye.

PATIENT SUMMARY

Hybrid indocyanine green (ICG)-^99mTc-nanocolloid is a safe and reliable sentinel node (SN) tracer, as established in this large series of 400 penile cancer patients (740 groins). It enables accurate pre- and intraoperative SN identification and significantly improves SN detection rate compared with blue dye, without staining the surgical field or the need for an additional injection.

Application of Nanomaterials in Biomedical Imaging and Cancer Therapy

Nanomaterials, such as nanoparticles, nanorods, nanosphere, nanoshells, and nanostars, are very commonly used in biomedical imaging and cancer therapy. They make excellent drug carriers, imaging contrast agents, photothermal agents, photoacoustic agents, and radiation dose enhancers, among other applications. Recent advances in nanotechnology have led to the use of nanomaterials in many areas of functional imaging, cancer therapy, and synergistic combinational platforms. This review will systematically explore various applications of nanomaterials in biomedical imaging and cancer therapy. The medical imaging modalities include magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computerized tomography, optical imaging, ultrasound, and photoacoustic imaging. Various cancer therapeutic methods will also be included, including photothermal therapy, photodynamic therapy, chemotherapy, and immunotherapy. This review also covers theranostics, which use the same agent in diagnosis and therapy. This includes recent advances in multimodality imaging, image-guided therapy, and combination therapy. We found that the continuous advances of synthesis and design of novel nanomaterials will enhance the future development of medical imaging and cancer therapy. However, more resources should be available to examine side effects and cell toxicity when using nanomaterials in humans.

Recent advances in the management of penile cancer

Penile cancer is a rare condition and can be very complex to manage. Advances in surgical techniques, imaging, pathological classification and patient pathways have led to improved patient care. The diagnosis of pre-malignant change, penile cancer and metastatic disease along with advances in their treatment are detailed in this review which aims to update clinicians from multiple specialties and countries on penile cancer.

Current controversies and developments on the role of lymphadenectomy for penile cancer

Penile squamous cell carcinoma is a rare cancer in men. The main prognosticators of survival for penile cancer patients remain the presence and the extent of lymph node metastasis. While radical inguinal lymphadenectomy has been the cornerstone of regional lymph node management for many years, it is still associated with significant morbidity and psychological distress. Recent developments in penile squamous cell carcinoma management have been met with some controversy in the urologic oncology community. Herein, we review the current controversies and developments on the role of inguinal lymphadenectomy for penile cancer.

Sentinel lymph node imaging in urologic oncology

Lymph node (LN) metastases in urological malignancies correlate with poor oncological outcomes. Accurate LN staging is of great importance since patients can benefit from an optimal staging, accordingly aligned therapy and more radical treatments. Current conventional cross-sectional imaging modalities [e.g., computed tomography (CT) and magnetic resonance imaging (MRI)] are not accurate enough to reliably detect early LN metastases as they rely on size criteria. Radical lymphadenectomy, the surgical removal of regional LNs, is the gold standard of invasive LN staging. The LN dissection is guided by anatomic considerations of lymphatic drainage pathways of the primary tumor. Selection of patients for lymphadenectomy heavily relies on preoperative risk stratification and nomograms and, as a result a considerable number of patients unnecessarily undergo invasive staging with associated morbidity. On the other hand, due to individual variability in lymphatic drainage, LN metastases can occur outside of standard lymphadenectomy templates leading to potential understaging and undertreatment. In theory, metastases from the primary tumor need to pass through the chain of LNs, where the initial node is defined as the sentinel LN. In theory, identifying and removing this LN could lead to accurate assessment of metastatic status. Radiotracers and more recently fluorescent dyes and superparamagnetic iron oxide nanoparticles (SPION) are injected into the primary tumor or peritumoral and the sentinel LNs are identified intraoperatively by a gamma probe, fluorescent camera or a handheld magnetometer. Preoperative imaging [e.g., single-photon emission computed tomography (SPECT)/CT or MRI] after tracer injection can further improve preoperative planning of LN dissection. While sentinel LN biopsy is an accepted and widely used approach in melanoma and breast cancer staging, its use in urological malignancies is still limited. Most data published so far is in penile cancer staging since this cancer has a typical echelon-based lymphatic metastasizing pattern. More recent data is encouraging with low false-negative rates, but its use is limited to centers with high expertise. Current guidelines recommend sentinel LN biopsy as an accepted alternative to modified inguinal lymphadenectomy in patients with pT1G2 disease and non-palpable inguinal LNs. In prostate cancer, a high diagnostic accuracy could be demonstrated for the sentinel approach. Nevertheless, due to lack of data or high false-negative rates in other urological malignancies, sentinel LN biopsy is still considered experimental in other urological malignancies. More high-level evidence and longitudinal data is needed to determine its final value in those malignancies. In this manuscript, we will review sentinel node imaging for urologic malignancies.

European research trends in nuclear medicine

Written by associate editors of the Annals of Nuclear Medicine, this invited review article is intended to offer our readers a condensed global view on the high-quality research work that has been published in Europe last year. We have divided this article into five sections. The first three sections from the oncology category include "[¹⁸F]fluorodeoxyglucose (FDG) positron-emission tomography (PET) for therapy monitoring in malignant lymphoma", "[¹⁸F]fluoromisonidazole (FMISO) PET for hypoxia", and "lymphoscintigraphy update". It is followed by a section on "amyloid PET for Alzheimer's disease" using [¹¹C]Pittsburgh Compound B (PiB) and [¹⁸F]florbetapir from the neurology category. The final section reviews three original articles in the field of "basic and translational molecular imaging" regardless of the category, which investigated new PET tracers such as L-4-borono-2-[¹⁸F]fluoro-phenylalanine (FBPA), O-(2-[¹⁸F]fluoroethyl)-L-tyrosine (FET) and ⁶⁴Cu-NOTA-pertuzumab in small animals. We hope that this review article will arouse greater interest in our readers in recent European research trends in the field of nuclear medicine.

[Lymph node management of cN0 penile cancer]

In penile cancer, lymph node metastasis is the main known prognostic factor affecting patients' survival. Early inguinal lymph node dissection or the resection of clinically occult lymph node metastases improves survival compared with removal when the metastases become clinically apparent. Micrometastatic lymph node involvement is undetectable by current imaging modalities. Nomograms based on clinical and histopathological tumor characteristics are unreliable in predicting lymph node involvement. Consequently, in penile cancer patients with clinically normal inguinal lymph nodes (cN0) and a tumor stage ≥pT1, G2 surgical lymph node exploration is recommended. Radical inguinal lymphadenectomy is no longer recommended because of its invasiveness and high complication rate. Modified lymphadenectomy and dynamic sentinel lymph node surgery allow the detection of lymph node-positive patients with sufficient certainty. Thereby, the sentinel lymph node approach offers the least invasiveness and high sensitivity. Extended inguinal lymphadenectomy is still recommended in the case of positive nodes.