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

Lessons learned in application driven imaging agent design for image-guided surgery

To meet the growing demand for intraoperative molecular imaging, the development of compatible imaging agents plays a crucial role. Given the unique requirements of surgical applications compared to diagnostics and therapy, maximizing translational potential necessitates distinctive imaging agent designs. For effective surgical guidance, exogenous signatures are essential and are achievable through a diverse range of imaging labels such as (radio)isotopes, fluorescent dyes, or combinations thereof. To achieve optimal in vivo utility a balanced molecular design of the tracer as a whole is required, which ensures a harmonious effect of the imaging label with the affinity and specificity (e.g., pharmacokinetics) of a pharmacophore/targeting moiety. This review outlines common design strategies and the effects of refinements in the molecular imaging agent design on the agent's pharmacological profile. This includes the optimization of affinity, pharmacokinetics (including serum binding and target mediated background), biological clearance route, the achievable signal intensity, and the effect of dosing hereon.

Contemporary Role of Lymph Node Dissection in Genitourinary Cancers: Where Are We in 2023?

CONTEXT

Lymphadenectomy during surgery for genitourinary malignancies has varying benefits.

OBJECTIVE

To review contemporary evidence on lymph node dissection in genitourinary cancers.

EVIDENCE ACQUISITION

We performed a collaborative review to summarize current evidence supporting lymph node dissection in urothelial, prostate, kidney, penile, and testis cancers. We present the evidence on patient selection and recommended dissection templates, and highlight knowledge gaps and ongoing areas of investigation.

EVIDENCE SYNTHESIS

Lymph node dissection remains the reference standard for lymph node staging. Pathologic nodal stage informs prognosis and guides adjuvant treatment. Appropriate template and patient selection are paramount to optimize outcomes and capitalize on the selective therapeutic benefits.

CONCLUSIONS

Accurate staging with lymphadenectomy is contingent on appropriate template selection. The cumulative benefit will depend on judicious patient selection.

PATIENT SUMMARY

We performed a collaborative review by a diverse group of experts in urology. We reviewed current evidence on lymph node dissection.

Intraoperative image-guidance during robotic surgery: is there clinical evidence of enhanced patient outcomes?

BACKGROUND

To date, the benefit of image guidance during robot-assisted surgery (IGS) is an object of debate. The current study aims to address the quality of the contemporary body of literature concerning IGS in robotic surgery throughout different surgical specialties.

METHODS

A systematic review of all English-language articles on IGS, from January 2013 to March 2023, was conducted using PubMed, Cochrane library's Central, EMBASE, MEDLINE, and Scopus databases. Comparative studies that tested performance of IGS vs control were included for the quantitative synthesis, which addressed outcomes analyzed in at least three studies: operative time, length of stay, blood loss, surgical margins, complications, number of nodal retrievals, metastatic nodes, ischemia time, and renal function loss. Bias-corrected ratio of means (ROM) and bias-corrected odds ratio (OR) compared continuous and dichotomous variables, respectively. Subgroup analyses according to guidance type (i.e., 3D virtual reality vs ultrasound vs near-infrared fluoresce) were performed.

RESULTS

Twenty-nine studies, based on 11 surgical procedures of three specialties (general surgery, gynecology, urology), were included in the quantitative synthesis. IGS was associated with 12% reduction in length of stay (ROM 0.88; p = 0.03) and 13% reduction in blood loss (ROM 0.87; p = 0.03) but did not affect operative time (ROM 1.00; p = 0.9), or complications (OR 0.93; p = 0.4). IGS was associated with an estimated 44% increase in mean number of removed nodes (ROM 1.44; p < 0.001), and a significantly higher rate of metastatic nodal disease (OR 1.82; p < 0.001), as well as a significantly lower rate of positive surgical margins (OR 0.62; p < 0.001). In nephron sparing surgery, IGS significantly decreased renal function loss (ROM 0.37; p = 0.002).

CONCLUSIONS

Robot-assisted surgery benefits from image guidance, especially in terms of pathologic outcomes, namely higher detection of metastatic nodes and lower surgical margins. Moreover, IGS enhances renal function preservation and lowers surgical blood loss.

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.

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.

Engineered live bacteria as disease detection and diagnosis tools

Sensitive and minimally invasive medical diagnostics are essential to the early detection of diseases, monitoring their progression and response to treatment. Engineered bacteria as live sensors are being developed as a new class of biosensors for sensitive, robust, noninvasive, and in situ detection of disease onset at low cost. Akin to microrobotic systems, a combination of simple genetic rules, basic logic gates, and complex synthetic bioengineering principles are used to program bacterial vectors as living machines for detecting biomarkers of diseases, some of which cannot be detected with other sensing technologies. Bacterial whole-cell biosensors (BWCBs) can have wide-ranging functions from detection only, to detection and recording, to closed-loop detection-regulated treatment. In this review article, we first summarize the unique benefits of bacteria as living sensors. We then describe the different bacteria-based diagnosis approaches and provide examples of diagnosing various diseases and disorders. We also discuss the use of bacteria as imaging vectors for disease detection and image-guided surgery. We conclude by highlighting current challenges and opportunities for further exploration toward clinical translation of these bacteria-based systems.

Surgical templates for inguinal lymph node dissection in cN0 penile cancer: A comparative study

PURPOSE

Modified and superficial inguinal lymph node dissection (MILD and SILD) are the 2 widely used templates for surgical staging of clinically node negative (cN0) penile cancer (PeCa); however, no previous reports have compared their outcomes. We compared these 2 surgical templates for oncological outcomes and complications.

MATERIALS AND METHODS

We retrospectively reviewed records of cN0 PeCa patients who underwent MILD/SILD at our cancer care center from January 2013 to December 2019. Patients who developed a penile recurrence during follow up were excluded from analysis of oncological outcomes. The 2 groups (MILD and SILD) were compared for baseline clinico-pathological characteristics. The primary outcome was the groin recurrence free survival (gRFS). Secondary outcomes included the false negative rate (FNR) and disease free survival (DFS) for both templates and also the post-operative wound related complication.

RESULTS

Of the 146 patients with intermediate and high risk N0 PeCa, 74 (50.7%) and 72 (49.3%) underwent MILD and SILD respectively. The 2 groups were comparable with regards to the distribution of T stage, tumor grade and the proportion of intermediate and high-risk patients. At a median follow up of 34 months (47 for SILD and 23 for MILD), a total of 5 groin recurrences were encountered; all of them occurred in the MILD group. The gRFS and DFS for the MILD group was 93.2% and 91.8% respectively; while that for the SILD group was 100% and 94.4% respectively. Too few events had occurred to determine any statistically significant difference. The FNR for MILD and SILD was 26.3% and 0% respectively. The overall complication rate was significantly higher in the SILD group (46% vs 20.3%, p=0.001), especially for Clavien Dindo 3A complications.

CONCLUSION

MILD can fail to pick up micro-metastatic disease in a small proportion of cN0 PeCa patients, while SILD provides better oncological clearance with no groin recurrences. This oncological superiority comes at the cost of a higher incidence of wound-related complications.

Performance of indocyanine green in sentinel lymph node mapping and lymph node metastasis in penile cancer: systematic review, meta-analysis, and single-center experience

PURPOSE

The aim of this study was to investigate the overall sensitivity and specificity of indocyanine green (ICG)-near-infrared (NIR) fluorescence imaging in the detection of sentinel lymph node metastasis (SLNM) in penile cancer.

METHODS

We searched PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases to identify manuscripts where ICG was intravenously administered prior to or during penile cancer surgery, with no restriction on language or publication status. The results extracted are presented as forest plots.

RESULTS

Seven studies were included in the analysis. The median sensitivity and specificity of ICG-NIR imaging for SLNM detection were 100 and 4%, respectively; the pooled sensitivity was 100.0% (95% confidence interval [CI] 97.0-100.0) and specificity was 2.0% (95% CI 1.0-3.0). There was no significant difference in the diagnostic results between different injection sites and doses in each experimental group.

CONCLUSION

To our knowledge, this meta-analysis is the first to summarize the diagnostic performance of ICG-NIR imaging for SLNM detection in penile cancer. ICG is sensitive in the imaging of SLN tissue, which can consequently improve the accuracy of lymph node detection. However, the specificity is very low.

Improved outcome in penile cancer with radiologically enhanced stratification protocol for lymph node staging procedures: a study in 316 inguinal basins with a mean follow-up of 5 years

BACKGROUND

Lymph node metastasis is the main determinant of survival in penile cancer patients. Conventionally clinical palpability is used to stratify patients to Inguinal Lymph node dissection (ILND) if clinically node positive (cN +) or Dynamic sentinel node biopsy (DSNB) if clinically node negative (cN0). Studies suggest a false negative rate (FNR) of around 10% (5-13%) for DSNB. To our knowledge there are no studies reporting harder end point of survival and outcomes of all clinically node positive (cN +) patients. We present our outcome data of all patients with penile cancer including false negative rates and survival in both DSNB and ILND groups.

METHODS

One hundred fifty-eight consecutive patients (316 inguinal basins), who had lymph node surgery for penile cancer in a tertiary referral centre from Jan 2008 to 2018, were included in the study. All patients underwent ultrasound (US) ± fine needle aspiration cytology (FNAC) and then MRI/ CT, if needed, to stage their disease. We used combined clinical and radiological criteria (node size, architecture loss, irregular margins) to stratify patients to DSNB vs ILND as opposed to clinical palpability alone.

RESULTS

11.2% i.e., 27/241 inguinal basins had lymph node positive disease by DSNB. 54.9% i.e., 39/71 inguinal basins (IBs) had lymph node-positive disease by ILND. 4 inguinal basins with no tracer uptake in sentinel node scans are being monitored at patient's request and have not had any recurrences to date. With a mean follow-up of 65 months (range 24-150), the false-negative rate (FNR) for DSNB is 0%. Judicious uses of cross-sectional imaging necessitated ILND in 2 inguinal basins with non-palpable nodes and negative US with false positive rate of 6.3% (2/32) for ILND. The same cohort of DSNB patients might have had 11.1% (3/27) FNR if only palpability criteria was used. 43 (28%) patients who did require cross sectional imaging as per our criteria had a low node positive rate of 4.7% (p = 0.03). Mean cancer specific survival of all node-positive patients was 105 months.

CONCLUSION

The performance of DSNB improved with enhanced radiological stratification of patients to either DSNB or ILND. We for the first time report the comprehensive outcome of all lymph node staging procedures in penile cancer.

Role of Nuclear Sentinel Lymph Node Mapping Compared to New Alternative Imaging Methods

With the emergence of sentinel node technology, many patients can be staged histopathologically using lymphatic mapping and selective lymphadenectomy. Structural imaging by using US, CT and MR permits precise measurement of lymph node volume, which is strongly associated with neoplastic involvement. Sentinel lymph node detection has been an ideal field of application for nuclear medicine because anatomical data fails to represent the close connections between the lymphatic system and regional lymph nodes, or, more specifically, to identify the first draining lymph node. Hybrid imaging has demonstrated higher accuracy than standard imaging in SLN visualization on images, but it did not change in terms of surgical detection. New alternatives without ionizing radiations are emerging now from "non-radiological" fields, such as ophthalmology and dermatology, where fluorescence or opto-acoustic imaging, for example, are widely used. In this paper, we will analyze the advantages and limits of the main innovative methods in sentinel lymph node detection, including innovations in lymphoscintigraphy techniques that persist as the gold standard to date.

Comparison of two hybrid sentinel node tracers: indocyanine green (ICG)-99mTc-nanocolloid vs. ICG-99mTc-nanoscan from a nuclear medicine and surgical perspective

BACKGROUND

Lymph node (LN) metastasis is a relevant predictor for survival in patients with a.o. penile cancer (PeCa), malignant melanoma. The sentinel node (SN) procedure comprises targeted resection of the first tumour-draining SNs. Here, the hybrid tracer indocyanine green (ICG)-99mTc-nanocolloid has been used for several years to combine optical and nuclear detection. Recently, the resource of the nanocolloid precursor stopped production and the precursor was replaced by a different but chemically comparable colloid, nanoscan. Our aim was to study the performance of ICG-99mTc-nanoscan compared to ICG-99mTc-nanocolloid from a nuclear and surgical perspective.

METHODS

Twenty-four patients with either PeCa or head-and-neck (H&N) melanoma and scheduled for a SN procedure were included. The initial group (n = 11) received ICG-99mTc-nanocolloid until no longer available; the second group (n = 13) received ICG-99mTc-nanoscan. Tracer uptake was assessed on lymphoscintigraphy and single-photon emission (SPECT). Intraoperatively, SNs were identified using gamma tracing and fluorescence imaging. Ex vivo (back-table) measurements were conducted to quantify the fluorescence emissions. Chemical analysis was performed to compare the ICG assembly on both precursors.

RESULTS

The mean tracer uptake in the SNs was similar for ICG-99mTc-nanocolloid (2.2 ± 4.3%ID) and ICG-99mTc-nanoscan (1.8 ± 2.6%ID; p = 0.68). 3 SNs (interquartile range (IQR) 3-4) were detected on lymphoscintigraphy in PeCa patients receiving ICG-99mTc-nanoscan compared to 2 SNs (IQR 2-3) in PeCa patients receiving ICG-99mTc-nanocolloid (p = 0.045), no differences were observed in H&N patients. Back-table measurements of resected SNs revealed a lower total fluorescence intensity in the ICG-99mTc-nanoscan group (24*109 arbitrary units (A.U) IQR 1.6*109-14*109 in the ICG-99mTc-nanocolloid group versus 4.6*109 A.U. IQR 2.4*109-42*109 in the ICG-99mTc-nanoscan group, p = 0.0054). This was consistent with a larger degree of "stacked" ICG observed in the nanoscan formulation. No tracer-related adverse events were reported.

CONCLUSIONS

Based on this retrospective analysis, we can conclude that ICG-99mTc-nanoscan has similar capacity for SN identification as ICG-99mTc-nanocolloid and can safely be implemented in SN procedures.

The Use of Indocyanine Green and Near-Infrared Fluorescence Imaging Versus Blue Dye in Sentinel Lymph Node Biopsy in Cutaneous Melanoma: A Retrospective, Cohort Study

BACKGROUND

The use of indocyanine green (ICG) and near-infrared fluorescence imaging is a promising option for sentinel lymph node (SLN) mapping in cutaneous melanoma. The study objective was to compare the performance of ICG and blue dye at detecting SLNs with radioisotope nanocolloid (technetium-99).

METHODS

Between April 2018 and June 2022, 293 consecutive patients with cutaneous melanoma (Breslow thickness ≥ 0.8 mm) underwent wide local excision and SLN biopsy. Patients were divided into group A (ICG; n = 122) and group B (blue dye; n = 163). All patients underwent SPECT/CT imaging preoperatively. SLN detection parameters and complications were compared between the groups.

RESULTS

A total of 285 patients had complete data and were included in the analysis. The median age was 62.0 (range 10-91) years, and 139 (48.8%) were female patients. The mean Breslow thickness was 2.6 mm, 89 (31.2%) patients had ulceration, and 179 (62.8%) patients had mitosis ≥ 1 mm2. The mean number of SLNs detected per patient in group A was 1.58 and group B was 1.48. In groups A and B, the SLN detection rate was 96.7% versus 89.6% (p = 0.022) and the pathological SLN detection rate was 92.3% versus 97.1% (p = 0.481), respectively.

CONCLUSIONS

ICG had a higher SLN detection rate and equal pathological SLN detection rate to blue dye. ICG may not be inferior to blue dye and is a useful adjunct to radioisotope in SLN biopsy in cutaneous melanoma.

Exploring the Applications of Indocyanine Green in Robot-Assisted Urological Surgery: A Comprehensive Review of Fluorescence-Guided Techniques

This comprehensive review aims to explore the applications of indocyanine green (ICG) in robot-assisted urological surgery through a detailed examination of fluorescence-guided techniques. An extensive literature search was conducted in PubMed/MEDLINE, EMBASE and Scopus, using keywords such as "indocyanine green," "ICG", "NIRF", "Near Infrared Fluorescence", "robot-assisted", and "urology". Additional suitable articles were collected by manually cross-referencing the bibliography of previously selected papers. The integration of the Firefly^® technology in the Da Vinci^® robotic system has opened new avenues for the advancement and exploration of different urological procedures. ICG is a fluorophore widely used in near-infrared fluorescence-guided techniques. The synergistic combination of intraoperative support, safety profiles and widespread availability comprises an additional asset that empowers ICG-guided robotic surgery. This overview of the current state of the art illustrates the potential advantages and broad applications of combining ICG-fluorescence guidance with robotic-assisted urological surgery.

Indocyanine green combined with methylene blue versus methylene blue alone for sentinel lymph node biopsy in breast cancer: a retrospective study

BACKGROUND

Recent studies have shown that near-infrared (NIR) fluorescence imaging using Indocyanine green (ICG) may improve the efficiency of sentinel lymph node biopsy (SLNB). This study aimed to assess the effectiveness of the combination of ICG and methylene blue (MB) in breast cancer patients undergoing SLNB.

PATIENTS AND METHOD

We evaluated ICG plus MB (ICG + MB) identification effectiveness with MB alone using retrospective analysis. From 2016 to 2020, we collected data on 300 eligible breast cancer patients who got SLNB treatment in our institution by ICG + MB or MB alone. By comparing the distribution of clinicopathological characteristics, the detection rate of sentinel lymph nodes (SLNs) and metastatic SLNs, as well as the total number of SLNs in the two groups, we were able to assess the imaging efficiency.

RESULTS

Fluorescence imaging allowed 131 out of 136 patients in the ICG + MB group to find SLNs. ICG + MB group and MB group had detection rates of 98.5% and 91.5% (P = 0.007, χ² = 7.352), respectively. Besides, the ICG + MB approach was able to produce improved recognition outcomes. What's more, compared with the MB group, the ICG + MB group can identify more lymph nodes (LNs) (3.1 to 2.6, P = 0.000, t = 4.447). Additionally, in the ICG + MB group, ICG could identify more LNs than MB (3.1 vs 2.6, P = 0.004, t = 2.884).

CONCLUSION

ICG has high detection effectiveness for SLNs, and when paired with MB, the detection efficiency can be increased even further. Furthermore, the ICG + MB tracing mode does not involve radioisotopes, which has a lot of promise for clinical use and can take the place of conventional standard detection methods.

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.

Long-term oncological results in penile cancer treated by inguinal lymphadenectomy

PURPOSE

In 95% of cases, penile cancer is a squamous cell carcinoma whose specificity is lymphatic spread with the inguinal lymph nodes as the first relay route. Inguinal lymph node dissection is a primordial part of the treatment. The objective was to assess the oncological results of inguinal lymph node dissection in penile cancer at our centre.

METHODS

We retrospectively included all patients having undergone inguinal lymph node dissection at our centre between 1 January 2004 and 1 January 2020 for the treatment of penile cancer. Patients for whom lymphadenopathy was palliative were excluded. Depending on indications, the procedures consisted in either dynamic sentinel node biopsy, modified lymphadenectomy or radical lymphadenectomy. All cancers were reclassified using the 2016 TNM classification system. Survival was analysed according to the Kaplan-Meier method.

RESULTS

242 inguinal lymph node dissections were performed in 122 patients. There were 71 pN0 (58%), 9 pN1 (7%), 4 pN2 (3%) and 38 pN3 (31%). Mean follow-up was 51 ± 45 months. The 3-year recurrence-free survival rate was 76% in pN0 patients and 17% in pN3 patients. The 5-year specific and overall survival rates were, respectively, 82% and 73% for pN0 stages, and 14% and 17% for pN3 stages. Extracapsular extension on an inguinal lymphadenopathy appeared as a highly negative prognostic factor.

CONCLUSION

Inguinal lymph node dissection is essential in the treatment of penile cancer. Recurrence-free, specific and overall survival are closely linked to the lymph node stage. Extracapsular extension and pelvic lymph node invasion are highly negative prognostic factors.

Variations in Penile Cancer Management: Results From the Global Society of Rare Genitourinary Tumors Survey

INTRODUCTION

There is paucity of evidence and consensus on various aspects of management of penile cancer (PeCa), which is intuitive considering the rarity of this disease. We present here the details of an online survey conducted by the Global Society of Rare Genito-urinary Tumors (GSRGT) with the aim of capturing the variations in PeCa care across different regions of the world.

MATERIALS AND METHODS

An online questionnaire was developed by experts within the GSRGT and then circulated via email in English and Spanish versions to clinicians dealing with PeCa. Respondents were allowed 8 weeks to reply.

RESULTS

We received 102 responses; the majority of them were from South America (37.2%) followed by North America and Asia (17.6% each). Only 11.7% of the respondents treated more than 25 patients with PeCa annually. Total penectomy is performed by 21.5% of the respondents in >50% of their patients. Less than a fifth of the experts (19.6%) responded that >50% of their patients are clinically node-negative (cN0) at presentation. For intermediate-risk cN0 patients (T1 G2 cancer), about a third of the experts chose surveillance. For invasive inguinal staging, the options of Dynamic Sentinel Lymph Node Biopsy (DSNB), Modified Inguinal Lymph Node Dissection (MILD), Superficial Inguinal Lymph Node Dissection (SILD), and Video-Endoscopic Inguinal Lymphadenectomy (VEIL) were chosen by 28.4%, 26.4%, 31.3%, and 13.7% of the respondents respectively. Considerable variation was seen in the worldwide use of these techniques. For clinically node-positive patients, respondents were in favor of giving adjuvant chemotherapy instead of neoadjuvant chemotherapy, except for cN3 patients.

CONCLUSION

The results of this questionnaire objectified the variations in global practices in the management of PeCa. This serves as the baseline information which can help prioritize research areas for multinational collaborative efforts, a key mission of the GSRGT.

European Association of Urology-American Society of Clinical Oncology Collaborative Guideline on Penile Cancer: 2023 Update

CONTEXT

Penile cancer is a rare disease but has a significant impact on quality of life. Its incidence is increasing, so it is important to include new and relevant evidence in clinical practice guidelines.

OBJECTIVE

To provide a collaborative guideline that offers worldwide physician and patient guidance for the management of penile cancer.

EVIDENCE ACQUISITION

Comprehensive literature searches were performed for each section topic. In addition, three systematic reviews were conducted. Levels of evidence were assessed, and a strength rating for each recommendation was assigned according to the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology.

EVIDENCE SYNTHESIS

Penile cancer is a rare disease but its global incidence is increasing. Human papillomavirus (HPV) is the main risk factor for penile cancer and pathology should include an assessment of HPV status. The main aim of primary tumour treatment is complete tumour eradication, which has to be balanced against optimal organ preservation without compromising oncological control. Early detection and treatment of lymph node (LN) metastasis is the main determinant of survival. Surgical LN staging with sentinel node biopsy is recommended for patients with a high-risk (≥pT1b) tumour with cN0 status. While (inguinal) LN dissection remains the standard for node-positive disease, multimodal treatment is needed in patients with advanced disease. Owing to a lack of controlled trials and large series, the levels of evidence and grades of recommendation are low in comparison to those for more common diseases.

CONCLUSIONS

This collaborative penile cancer guideline provides updated information on the diagnosis and treatment of penile cancer for use in clinical practice. Organ-preserving surgery should be offered for treatment of the primary tumour when feasible. Adequate and timely LN management remains a challenge, especially in advanced disease stages. Referral to centres of expertise is recommended.

PATIENT SUMMARY

Penile cancer is a rare disease that significantly impacts quality of life. While the disease can be cured in most cases without lymph node involvement, management of advanced disease remains challenging. Many unmet needs and unanswered questions remain, underlining the importance of research collaborations and centralisation of penile cancer services.

Morbidity and risk factors for complications of inguinal lymph node dissection in penile cancer

PURPOSE

To assess the morbidity of inguinal lymph node dissection (ILND) in penile cancer, then to compare this morbidity with that of ILND performed in the context of skin cancer treatment.

METHODS

We retrospectively included all patients having undergone ILND between 1 January 2004 and 31 December 2019 in our centre's urology department in the context of treatment of penile cancer or skin cancer. Postoperative complications were reported in accordance with the Clavien-Dindo classification system.

RESULTS

Two hundred forty-two ILNDs were performed in 122 patients with penile cancer and 56 ILNDs were performed in 56 patients with skin cancer. The most common early complication was postoperative fluid collection (lymphocele or haematoma), which complicated 44% of ILNDs overall and 60% of radical lymphadenectomies. The most common late complication was leg lymphoedema, found in up to 36% of radical lymphadenectomies. Major complications (grade ≥ III) were very rare (4% of radical lymphadenectomies). Radical lymphadenectomies resulted in significantly more cases of postoperative fluid collection, skin necrosis and dehiscence, as well as leg lymphoedema, than modified lymphadenectomy techniques. Two factors significantly increasing postoperative morbidity were demonstrated: ASA score = 3 (OR = 3.09) and operating time (OR = 1.01).

CONCLUSION

ILNDs are morbid surgical procedures for which the indications must be well defined. However, the complications are almost exclusively minor, for a major oncological benefit.

Study on naked eye tracing of inguinal sentinel lymph nodes in penile cancer patients with carbon nanoparticle suspension injection

Objective

Exploratory study of the effect and clinical value of carbon nanoparticle suspension injection (CNSI) as a tracer for inguinal sentinel lymph nodes in penile cancer.

Method

We selected 29 patients with penile cancer in our department from January 2019 to October 2022. According to whether the CNSI tracer was injected during the pathological biopsy of the inguinal lymph nodes, the enrolled patients were assigned to the control group, the group in which CNSI was injected 12 h before the surgery (12HBS group) and the group in which CNSI was injected 0.5 h before the surgery (0.5HBS group). Evaluating the effectiveness of CNSI as a lymphatic tracer involves analyzing the following: its safety, the statistical analysis of the detection rate (DR) of different groups, the number of lymph nodes sent for each case (NOLNSFEC), the difference of positive rate of lymphatic metastasis (PROLM), and operation time (OT).

Results

The lymph nodes in the 12HBS group and 0.5HBS group had an obvious black staining appearance, and no adverse reactions or surgical complications were found. Most of the black-stained areas caused by CNSI injection were removed with penile excision, which did not affect the postoperative appearance. This did not affect the pathological analysis. The DR of lymph nodes in the 12HBS group was higher (p < 0.05) than that in the control group. More lymph nodes were removed for examination (p < 0.05), which improved the efficiency of surgery. Compared with the 12HBS group, the number of lymph nodes removed in the 0.5HBS group decreased (p < 0.05). The OT was shortened (p < 0.05), but there was no significant difference in the DR and PROLM.

Conclusion

CNSI was applied to the naked-eye tracing of inguinal sentinel lymph nodes in penile cancer, which is safe and efficient. Injection of CNSI 0.5 h before surgery can help identify the "foremost position" of sentinel lymph nodes and reduce surgical trauma.

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.

Clinical translational barriers against nanoparticle-based imaging agents

Nanoparticle based imaging agents (NIAs) have been intensively explored in bench studies. Unfortunately, only a few cases have made their ways to clinical translation. In this review, clinical trials of NIAs were investigated for understanding possible barriers behind that. First, the complexity of multifunctional NIAs is considered a main barrier because it brings uncertainty to batch-to-batch fabrication, and results in sophisticated in vivo behaviors. Second, inadequate biosafety studies slow down the translational work. Third, NIA uptake at disease sites is highly heterogeneous, and often exhibits poor targeting efficiency. Focusing on the aforementioned problems, key design parameters were analyzed including NIAs' size, composition, surface characteristics, dosage, administration route, toxicity, whole-body distribution and clearance in clinical trials. Possible strategies were suggested to overcome these barriers. Besides, regulatory guidelines as well as scale-up and reproducibility during manufacturing process were covered as they are also key factors to consider during clinical translation of NIAs.

French AFU Cancer Committee Guidelines - Update 2022-2024: penile cancer

OBJECTIVE

To update French oncology guidelines concerning penile cancer.

METHODS

Comprehensive Medline search between 2020 and 2022 upon diagnosis, treatment and follow-up of testicular germ cell cancer to update previous guidelines. Level of evidence was evaluated according to AGREE-II.

RESULTS

Epidermoid carcinoma is the most common penile cancer histology. Physical examination is mandatory to define local and inguinal nodal cancer stage. MRI with artificial erection can help to assess deep infiltration in cases of organsparing intention. Node negative patients (defined by palpation and imaging) will present micro nodal metastases in up to 25% of cases. Invasive lymph node assessment is thus advocated except for low risk patients. Sentinel node dynamic biopsy is the first line technique. Modified bilateral inguinal lymphadenectomy is an option with higher morbidity. 18-FDG-PET is recommended in patients with palpable nodes. Chest, abdominal and pelvis computerized tomography is an option. Fine needle aspiration (when positive) is an easy way to assess inguinal palpable node pathological involvement. Its results determine the type of lymphadenectomy to be performed (for diagnostic or curative purposes). Treatment is mostly surgical. Free margins status is essential, but it also has to be organ-sparing when possible. Brachytherapy and topic agents can cure in selected cases. Lymph node assessment should be synchronous to the removal of the tumour when possible. Limited inguinal lymph node involvement (pN1 stage) can be cured with the only lymphadenectomy. In case of larger lymph node stage, one should consider multidisciplinary treatment including chemotherapy and inclusion in a trial.

CONCLUSIONS

Penile cancer needs demanding surgery to be cured, surrounded by chemotherapy in node positive patients. Lymph nodes involvement is a major prognostic factor. Thus, inguinal node assessment cannot be neglected.

Stannous colloid mixed with indocyanine green as a tracer for sentinel lymph node navigation surgery

The combined use of a vital dye and radioactive colloid reportedly performs better in detecting sentinel lymph nodes (SLNs) for cancers than the use of either of them alone. However, especially for gastric cancer, two endoscopic procedures are required to administer these two tracers, which burdens the patients and practitioners. Here we propose the use of stannous colloid (SnC) mixed with indocyanine green (ICG) as a new mixed tracer (SnC-ICG); its characteristics were investigated in vivo and in vitro to estimate its usefulness for SLN navigation. The tracers were administered to rats and the accumulation of radioactivity and/or near-infrared fluorescence were evaluated in the regional lymph nodes (LNs) using single positron emission computed tomography and near-infrared fluorescence imaging, respectively. SnC-ICG showed significantly better clearance from the injection site and better migration to primary LNs than the single administration of SnC or ICG aqueous solution. SnC-ICG demonstrated a wide particle size variability, stabilized to 1200-nm upon the addition of albumin in vitro; These properties could contribute to its behavior in vivo. The use of SnC-ICG could contribute better performance to detect SLNs for gastric cancer with less burden on both patients and medical practitioners.

The current status and future prospects for molecular imaging-guided precision surgery

Molecular imaging technologies are increasingly used to diagnose, monitor, and guide treatment of i.e., cancer. In this review, the current status and future prospects of the use of molecular imaging as an instrument to help realize precision surgery is addressed with focus on the main components that form the conceptual basis of intraoperative molecular imaging. Paramount for successful interventions is the relevance and accessibility of surgical targets. In addition, selection of the correct combination of imaging agents and modalities is critical to visualize both microscopic and bulk disease sites with high affinity and specificity. In this context developments within engineering/imaging physics continue to drive the growth of image-guided surgery. Particularly important herein is enhancement of sensitivity through improved contrast and spatial resolution, features that are critical if sites of cancer involvement are not to be overlooked during surgery. By facilitating the connection between surgical planning and surgical execution, digital surgery technologies such as computer-aided visualization nicely complement these technologies. The complexity of image guidance, combined with the plurality of technologies that are becoming available, also drives the need for evaluation mechanisms that can objectively score the impact that technologies exert on the performance of healthcare professionals and outcome improvement for patients.

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.

Radioisotope-Guided Sentinel Lymph Node Biopsy in Penile Cancer: A Long-Term Follow-Up Study

Lymph node (LN) management is critical for survival in patients with penile cancer. However, radical inguinal lymphadenectomy carries a high risk of postoperative complications such as lymphedema, lymphocele, wound infection, and skin necrosis. The European Association of Urology guidelines therefore recommend invasive LN staging by modified inguinal lymphadenectomy or dynamic sentinel node biopsy (DSNB) in clinically node-negative patients (cN0) with intermediate- and high-risk tumors (≥ T1G2). However, the timing of DSNB (simultaneous vs. subsequent to partial or total penile resection) is controversial and the low incidence of penile cancer means that data on the long-term outcomes of DSNB are limited. The present study aimed to analyze the reliability and morbidity of DSNB in patients with penile cancer during long-term follow-up. This retrospective study included 41 patients (76 groins) who underwent radioisotope-guided DSNB simultaneously or secondarily after penile surgery from June 2004 to November 2018. In total, 193 sentinel LNs (SLNs) and 39 non-SLNs were removed. The median number of dissected LNs was 2.5 (interquartile range 2–4). Histopathological analysis showed that five of the 76 groins (6.6%) contained metastases. None of the non-SLNs were tumor-positive. In accordance with the guidelines, all inguinal regions with positive SLNs underwent secondary radical inguinal lymphadenectomy, which revealed three additional metastases in one groin. Regional LN recurrence was detected in three patients (four groins) during a median follow-up of 70 months, including two patients in whom DSNB had been performed secondarily after repetitive penile tumor resections. DSNB-related complications occurred in 15.8% of groins. Most complications were mild (Clavien–Dindo grade I; 50%) or moderate (II; 25%), and invasive intervention was only required in 3.9% of groins (IIIa: n = 1; IIIb: n = 2). In summary, this study suggests that the current radioisotope-guided DSNB procedure may reduce the complication rate of inguinal lymphadenectomy in patients with cN0 penile cancer. However, DSNB and penile surgery should be performed simultaneously to minimize the false-negative rate. Recent advances, such as new tracers and imaging techniques, may help to reduce the false-negative rate of DSNB further.

A Review of Nuclear Medicine Approaches in the Diagnosis and the Treatment of Gynecological Malignancies

Nuclear medicine is defined as the diagnosis and the treatment of disease using radiolabeled compounds known as radiopharmaceuticals. Single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computer tomography (PET/CT) based radiopharmaceuticals have proven reliable in diagnostic imaging in nuclear medicine and cancer treatment. One of the most critical cancers that also relies on an early diagnosis is gynecological cancer. Given that approximately 25% of all cancers in developing countries are a subset of gynecological cancer, investigating this cancer subtype is of significant clinical worth, particularly in light of its high rate of mortality. With accurate identification of high grade distant abdominal endometrial cancer as well as extra abdominal metastases, 18F-Fluorodeoxyglucose ([18F]FDG) PET/CT imaging is considered a valuable step forward in the investigation of gynecological cancer. Considering these factors, [18F]FDG PET/CT imaging can assist in making management of patient therapy more feasible. In this literature review, we will provide a short overview of the role of nuclear medicine in the diagnosis of obstetric and gynecological cancers.

Incidence and risk factor analysis of complications after sentinel node biopsy for penile cancer

BACKGROUND

Surgical staging is recommended in intermediate to high risk clinically node negative (cN0) penile cancer (PeCa). Because (modified) inguinal lymph node dissection (ILND) is associated with high morbidity, dynamic sentinel node biopsy (DSNB) was introduced with the aim to reduce morbidity while maintaining diagnostic accuracy.

OBJECTIVE

To determine the incidence and types of complications after DSNB and identify risk factors for the occurrence of postoperative complications.

PATIENTS AND METHODS

We evaluated 644 PeCa patients (1284 DSNB procedures) with at least one cN0 groin who underwent DSNB between 2011 and 2020 at a single high-volume centre. 30-day and 30-90-day postoperative complications were collected according to the modified Clavien Dindo classification and the standardized methodology proposed by the European Association of Urology panel. Univariable and multivariable generalized linear mixed models were used to identify risk factors for the occurrence of complications per groin.

RESULTS

A 30-day postoperative complication occurred in 14% of groins (n=186), of which 94% were mild to moderate. Wound infection and lymphocele formation were most common. 30-90-day postoperative complications occurred in 3.4% of the groins, all of which were mild or moderate (grade 1-2). The number of removed LNs per groin was the main independent predictor for any 30-day complications and grade≥2 complications (OR 1.40; p<0.001). An increase in the probability of postoperative complications with the number of LNs removed was observed after accounting for all confounders.

CONCLUSIONS

Despite being less morbid than (modified) ILND, DSNB is still associated with a considerable risk of mild to moderate postoperative complications. This risk increases with an increasing number of LNs removed. Further procedural refinement aimed at removing the true sentinel node(s) only, may help further reduce the morbidity of surgical staging in PeCa.

Sentinel Node Methods in Penile Cancer - a Historical Perspective on Development of Modern Concepts

Malignant penile tumors are of squamous cell origin in more than 95% of cases and the occurrence of a distant metastasis without prior inguinal lymph node metastatic deposits is very rare. This makes inguinal lymph node staging very reliable and of great prognostic significance since undiscovered and untreated inguinal metastases may lead to a fatal clinical course. In lack of a sufficiently accurate noninvasive lymph node staging modality, penile cancer relies on surgical lymph node removal for regional staging. In this respect sentinel node biopsy offers a favourable minimally invasive alternative to prophylactic inguinal lymph node dissection which is associated with significant surgery-related morbidity. Today sentinel node biopsy is widely used in surgical oncology within high volume cancers such as breast cancer and melanoma. In rare cancers sentinel node biopsy is also emerging as a minimal invasive staging tool in patients with no obvious lymph node involvement. At several specialized units across Europe sentinel node biopsy has been practiced by dedicated specialist within vulva and penile cancer for more than two decades. In fact, the rare disease penile cancer was a model entity for development of the original sentinel node concept as early as the 1970'es due to work by the Paraguayan penile cancer pioneer, Cabañas, the sentinel node concept was subsequently successfully adapted in breast cancer and melanoma. This turned out mutually beneficial since the sequential development of sentinel node biopsy in penile cancer in the 1990s eventually adopted new insights and added conceptual details from the experiences harvested in the broader clinical application possible in these high-volume diseases. The prerequisite to conceptualising the sentinel node approach was the gradual anatomical and functional understanding of the lymphatic system which in western medicine rooted in ancient Greece and gradually increased in details and comprehension with significant contributions from many great notabilities during the last centuries including Hippocrates, Galen, Fallopio, Malpighi, Virchow, Starling, Cabañas, Hodgkin and Horenblas. Sentinel node biopsy in penile cancer is a complex multimodality procedure involving inguinal ultrasonography by radiologists, precise tracer-injection and interpretation of nuclear images by nuclear medicine physicians, radio-tracer- and dye guided open surgical biopsies by urologists and thorough step-sectioning, immunostaining and accurate lymph node specimen analysis by pathologists. This team effort requires well-tested protocols, experience and good collaboration and in rare diseases this calls for centralization of service.

How molecular imaging will enable robotic precision surgery : The role of artificial intelligence, augmented reality, and navigation

Molecular imaging is one of the pillars of precision surgery. Its applications range from early diagnostics to therapy planning, execution, and the accurate assessment of outcomes. In particular, molecular imaging solutions are in high demand in minimally invasive surgical strategies, such as the substantially increasing field of robotic surgery. This review aims at connecting the molecular imaging and nuclear medicine community to the rapidly expanding armory of surgical medical devices. Such devices entail technologies ranging from artificial intelligence and computer-aided visualization technologies (software) to innovative molecular imaging modalities and surgical navigation (hardware). We discuss technologies based on their role at different steps of the surgical workflow, i.e., from surgical decision and planning, over to target localization and excision guidance, all the way to (back table) surgical verification. This provides a glimpse of how innovations from the technology fields can realize an exciting future for the molecular imaging and surgery communities.

VEILND (Video Endoscopic Inguinal Lymph Node Dissection) with Florescence Indocyanine Green (ICG): A Novel Technique to Identify the Sentinel Lymph Node in Men with ≥pT1G2 and cN0 Penile Cancer

Introduction

In men with ≥pT1G2 cN0, penile cancer lymph node sampling is recommended with either (1) scintigraphically labelled Dynamic sentinel lymph node biopsy (DSLNB) or (2) modified inguinal lymph node dissection (MILND). Although DSLNB is a minimally invasive technique, the false negative rate can be about 10%, and a further operative procedure is required if positive. Open MILND is a diagnostic and therapeutic option but has a much higher morbidity. A potential compromise is the technique of LND-VEILND (video endoscopic inguinal LND) that can be combined with ICG florescence marking of sentinel lymph node (SLN). We present a pilot study of ICG-VEILND. The aim was to validate the applicability of a combination ICG marking of SLN in VEILND (to increase probability to excise SLN) and determine the optimal timing and dosage of ICG.

Materials and Methods

15 patients with VEILND (24 groins) underwent ICG application with fluorescence near-infrared (NIR 803⟶830 nm) detection. ICG is applied subcutaneously adjacent to the penile cancer or residual stump of penis or suprapubic region (in a history of total penectomy: 5 cases). The dose of 1.25 mg (ICG) was applied in one case with invisible SLN, the dose of 2.5 mg in 1 mL in 8 cases, and 5 mg in the remaining 6 patients (10 groins).

Results

Failure of marking SLN with ICG occurred in 25.0% of cases (6/24): due to application of 1.25 mg ICG, extensive metastasis to SLN, in 4 cases, the cause was unknown (16.7%, 4/24). In the short follow-up period, no local recurrence was seen in the pN0 ICG group.

Conclusion

Fluorescence infrared image with ICG dye increases the probability of removal of the SLN during VEILND. The dose of ICG is 2.5 (5) mg diluted in 1 ml and can be applied preoperatively even in the suprapubic region in men with a history of total penectomy, with an unexplainable failure of ICG marking in 16.7%.

Centralization and Equitable Care in Rare Urogenital Malignancies: The Case for Penile Cancer

Centralization of specialized care for rare cancers can improve patient outcomes. Inguinal lymph node evaluation is the most important clinical aspect of penile cancer care and is often neglected in a decentralized setting. Centralization of care may reduce system delays, improve guideline adherence, provide access to a wider team of specialists, and improve prognosis, albeit with some inconveniences for patients. PATIENT SUMMARY: We reviewed evidence for the centralization of care for penile cancer. Patients may have to travel greater distances to receive specialized care in expert centers. However, centralization means that rare cancers can be treated by more experienced surgeons, which can yield better outcomes in terms of survival and penis-preserving or reconstruction surgery.

Prognostic predictors of lymph node metastasis in penile cancer: a systematic review

PURPOSE

Squamous cell carcinoma (SCC) of the penis is a rare disease in developed countries but is associated with significant morbidity and mortality. A crucial prognostic factor is the presence of inguinal lymph node metastases (ILNM) at the time of diagnosis. At least 25% of cases have micrometastases at the time of diagnosis. Therefore, we performed a literature review of studies evaluating factors, both clinical and pathological, predictive of lymph node metastases in penile SCC.

MATERIALS AND METHODS

Studies were identified using PubMed and search terms included the following: penile cancer, penile tumor, penile neoplasm, penile squamous cell carcinoma, inguinal lymph node metastasis, lymph node metastases, nodal metastasis, inguinal node metastasis, inguinal lymph node involvement, predictors, and predictive factor. The number of patients and predictive factors were identified for each study based on OR, HR, or RR in multivariate analyses, as well as their respective significance values. These were compiled to generate a single body of evidence supportive of factors predictive of ILNM in penile SCC.

RESULTS

We identified 31 studies, both original articles and meta-analyses, which identified factors predictive of metastases in penile SCC. The following clinical factors were predictive of ILNM in penile SCC: lymphovascular invasion (LVI), increased grade, increased stage (both clinical and pathological), infiltrative and reticular invasion, increased depth of invasion, perineural invasion, and younger patient age at diagnosis. Biochemically, overexpression of p53, SOD2, Ki-67, and ID1 were associated with spread of SCC to inguinal lymph nodes. Diffuse PD-L1 expression, increased SCC-Ag expression, increased NLR, and CRP >20 were also associated with increased ILNM.

CONCLUSIONS

A multitude of factors are associated with metastasis of SCC of the penis to inguinal lymph nodes, which is associated with poor clinical outcomes. The above factors, most strongly LVI, grade, and node positivity, may be considered when constructing a nomogram to risk-stratify patients and determine eligibility for prophylactic inguinal lymphadenectomy.

High-Resolution 18F-FDG PET/CT for Assessing Three-Dimensional Intraoperative Margins Status in Malignancies of the Head and Neck, a Proof-of-Concept

The surgical treatment of head and neck malignancies relies on the complete removal of tumoral tissue, while inadequate margins necessitate the use of adjuvant therapy. However, most positive margins are identified postoperatively as deep margins, and intraoperative identification of the deep positive margins could help achieve adequate surgical margins and decrease adjuvant therapies. To improve deep-margin identification, we investigated whether the use of high-resolution preclinical PET and CT could increase certainty about the surgical margins in three dimensions. Patients with a malignancy of the head and neck planned for surgical resection were administered a clinical activity of 4MBq/kg ¹⁸F-FDG approximately one hour prior to surgical initiation. Subsequently, the resected specimen was scanned with a micro-PET-CT imaging device, followed by histopathological assessment. Eight patients were included in the study and intraoperative PET/CT-imaging of 11 tumoral specimens and lymph nodes of three patients was performed. As a result of the increased resolution, differentiation between inflamed and dysplastic tissue versus malignant tissue was complicated in malignancies with increased peritumoral inflammation. The current technique allowed the three-dimensional delineation of ¹⁸F-FDG using submillimetric PET/CT imaging. While further optimization and patient stratification is required, clinical implementation could enable deep margin assessment in head and neck resection specimens.

The role of fluorescent and hybrid tracers in radioguided surgery in urogenital malignancies

The increasing availability of new imaging technologies and tracers has enhanced the application of nuclear molecular imaging in urogenital interventions. In this context, preoperative nuclear imaging and radioactivity-based intraoperative surgical guidance have become important tools for the identification and anatomical allocation of tumor lesions and/or suspected lymph nodes. Fluorescence guidance can provide visual identification of the preoperatively defined lesions during surgery. However, the added value of fluorescence guidance is still mostly unknown. This review provides an overview of the role of fluorescence imaging in radioguided surgery in urogenital malignancies. The sentinel node (SN) biopsy procedure using hybrid tracers (radioactive and fluorescent component) serves as a prominent example for in-depth evaluation of the complementary value of radio- and fluorescence guidance. The first large patient cohort and long-term follow-up studies show: 1) improvement in the SN identification rate compared to blue dye; 2) improved detection of cancer-positive SNs; and 3) hints towards a positive effect on (biochemical) recurrence rates compared to extended lymph node dissection. The hybrid tracer approach also highlights the necessity of a preoperative roadmap in preventing incomplete resection. Recent developments focus on receptor-targeted approaches that allow intraoperative identification of tumor tissue. Here radioguidance is still leading, but fluorescent and hybrid tracers are also finding their way into the clinic. Emerging multiwavelength approaches that allow concomitant visualization of different anatomical features within the surgical field may provide the next step towards even more refined procedures.

The Click-On gamma probe, a second-generation tethered robotic gamma probe that improves dexterity and surgical decision-making

Purpose

Decision-making and dexterity, features that become increasingly relevant in (robot-assisted) minimally invasive surgery, are considered key components in improving the surgical accuracy. Recently, DROP-IN gamma probes were introduced to facilitate radioguided robotic surgery. We now studied if robotic DROP-IN radioguidance can be further improved using tethered Click-On designs that integrate gamma detection onto the robotic instruments themselves.

Methods

Using computer-assisted drawing software, 3D printing and precision machining, we created a Click-On probe containing two press-fit connections and an additional grasping moiety for a ProGrasp instrument combined with fiducials that could be video tracked using the Firefly laparoscope. Using a dexterity phantom, the duration of the specific tasks and the path traveled could be compared between use of the Click-On or DROP-IN probe. To study the impact on surgical decision-making, we performed a blinded study, in porcine models, wherein surgeons had to identify a hidden ⁵⁷Co-source using either palpation or Click-On radioguidance.

Results

When assembled onto a ProGrasp instrument, while preserving grasping function and rotational freedom, the fully functional prototype could be inserted through a 12-mm trocar. In dexterity assessments, the Click-On provided a 40% reduction in movements compared to the DROP-IN, which converted into a reduction in time, path length, and increase in straightness index. Radioguidance also improved decision-making; task-completion rate increased by 60%, procedural time was reduced, and movements became more focused.

Conclusion

The Click-On gamma probe provides a step toward full integration of radioguidance in minimal invasive surgery. The value of this concept was underlined by its impact on surgical dexterity and decision-making.

Beta radioguided surgery: towards routine implementation?

INTRODUCTION

In locally or locally advanced solid tumors, surgery still remains a fundamental treatment method. However, conservative resection is associated with high collateral damage and functional limitations of the patient. Furthermore, the presence of residual tumor tissue following conservative surgical treatment is currently a common cause of locally recurrent cancer or of distant metastases. Reliable intraoperative detection of small cancerous tissue would allow surgeons to selectively resect malignant areas: this task can be achieved by means of image-guided surgery, such as beta radioguided surgery (RGS).

EVIDENCE ACQUISITION

In this paper, a comprehensive review of beta RGS is given, starting from the physical principles that differentiate beta from gamma radiation, that has already its place in nuclear medicine current practice. Also, the recent clinical feasibility of using Cerenkov radiation is discussed.

EVIDENCE SYNTHESIS

Despite being first proposed several decades ago, only in the last years a remarkable interest in beta RGS has been observed, probably driven by the diffusion of PET radio tracers. Today several different approaches are being pursued to assess the effectiveness of such a technique, including both beta+ and beta- emitting radiopharmaceuticals.

CONCLUSIONS

Beta RGS shows some peculiarities that can present it as a very promising complementary technique to standard procedures. Good results are being obtained in several tests, both ex vivo and in vivo. This might however be the time to initiate the trials to demonstrate the real clinical value of these technologies with seemingly clear potential.

c-MET receptor-targeted fluorescence on the road to image-guided surgery in penile squamous cell carcinoma patients

In penile squamous cell carcinoma (pSCC), primary surgery aims to obtain oncologically safe margins while minimizing mutilation. Surgical guidance provided by receptor-specific tracers could potentially improve margin detection and reduce unnecessary excision of healthy tissue. Here, we present the first results of a prospective feasibility study for real-time intraoperative visualization of pSCC using a fluorescent mesenchymal-epithelial transition factor (c-MET) receptor targeting tracer (EMI-137). Methods: EMI-137 tracer performance was initially assessed ex vivo (N = 10) via incubation of freshly excised pSCC in a solution containing EMI-137 (500 nM). The in vivo potential of c-MET targeting and intraoperative tumour visualization was assessed after intravenous administration of EMI-137 in five pSCC patients scheduled for surgical resection using a Cyanine-5 (Cy5) fluorescence camera. Fluorescence imaging results were related to standard pathological tumour evaluation and c-MET immunohistochemistry. Three of the five in vivo patients also underwent a sentinel node resection after local administration of the hybrid tracer indocyanine green (ICG)-^99mTc-nanocolloid, which could be imaged using a near-infrared fluorescence camera. Results: No tracer-related adverse events were encountered. Both ex vivo and in vivo, EMI-137 enabled c-MET based tumour visualization in all patients. Histopathological analyses showed that all pSCC's expressed c-MET, with expression levels of ≥70% in 14/15 patients. Moreover, the highest c-MET expression levels were seen on the outside rim of the tumours, and a visual correlation was found between c-MET expression and fluorescence signal intensity. No complications were encountered when combining primary tumour targeting with lymphatic mapping. As such, simultaneous use of Cy5 and ICG in the same patient proved to be feasible. Conclusion: Fluorescence imaging of c-MET receptor-expressing pSCC tumours after intravenous injection of EMI-137 was shown to be feasible and can be combined with fluorescence-based lymphatic mapping. This combination is unique and paves the way towards further development of this surgical guidance approach.

Contemporary update of SPECT tracers and novelties in radioguided surgery: a perspective based on urology

Recent technical advances and implementation of novel radiotracers have further increased the potential of radioguided surgery for a broad variety of malignancies. Indeed, the possibilities for future applications of novel radiotracers in diverse oncological strategies has become more promising than ever. This literature review aims to provide a contemporary update on a selected group of radiotracers and evaluates the usability of radioguided surgery and sentinel node procedures, focusing on most promising advances. For example, the impact of targeted radiotracers on prostate specific membrane antigen (PSMA), CD206 receptor-targeted agents (^99mTc-tilmanocept), and hybrid tracers adding fluorescence to radioguidance (ICG-^99mTc-nanocolloid) as well as targeting hypoxia-induced carbonic anhydrase IX (CAIX) will be covered. Furthermore, future outlooks on the implementation of gold nanoparticles (AuNP's), but also technical advances in improved radiotracer detection by hybrid gamma devices will be discussed.

The Design and Preclinical Evaluation of a Single-Label Bimodal Nanobody Tracer for Image-Guided Surgery

Intraoperative guidance using targeted fluorescent tracers can potentially provide surgeons with real-time feedback on the presence of tumor tissue in resection margins. To overcome the limited depth penetration of fluorescent light, combining fluorescence with SPECT/CT imaging and/or gamma-ray tracing has been proposed. Here, we describe the design and preclinical validation of a novel bimodal nanobody-tracer, labeled using a “multifunctional single attachment point” (MSAP) label, integrating a Cy5 fluorophore and a diethylenetriaminepentaacetic acid (DTPA) chelator into a single structure. After conjugation of the bimodal MSAP to primary amines of the anti-HER2 nanobody 2Rs15d and ¹¹¹In-labeling of DTPA, the tracer’s characteristics were evaluated in vitro. Subsequently, its biodistribution and tumor targeting were assessed by SPECT/CT and fluorescence imaging over 24 h. Finally, the tracer’s ability to identify small, disseminated tumor lesions was investigated in mice bearing HER2-overexpressing SKOV3.IP1 peritoneal lesions. [¹¹¹In]In-MSAP.2Rs15d retained its affinity following conjugation and remained stable for 24 h. In vivo SPECT/CT and fluorescence images showed specific uptake in HER2-overexpressing tumors with low background. High tumor-to-muscle ratios were obtained at 1h p.i. and remained 19-fold on SPECT/CT and 3-fold on fluorescence images over 24 h. In the intraperitoneally disseminated model, the tracer allowed detection of larger lesions via nuclear imaging, while fluorescence enabled accurate removal of submillimeter lesions. Bimodal nuclear/fluorescent nanobody-tracers can thus be conveniently designed by conjugation of a single-molecule MSAP-reagent carrying a fluorophore and chelator for radioactive labeling. Such tracers hold promise for clinical applications.

Penile cancer

Penile squamous cell carcinoma (PSCC) is a rare cancer with orphan disease designation and a prevalence of 0.1-1 per 100,000 men in high-income countries, but it constitutes up to 10% of malignancies in men in some African, Asian and South American regions. Risk factors for PSCC include the absence of childhood circumcision, phimosis, chronic inflammation, poor penile hygiene, smoking, immunosuppression and infection with human papillomavirus (HPV). Several different subtypes of HPV-related and non-HPV-related penile cancers have been described, which also have different prognostic profiles. Localized disease can be effectively managed by topical therapy, surgery or radiotherapy. As PSCC is characterized by early lymphatic spread and imaging is inadequate for the detection of micrometastatic disease, correct and upfront surgical staging of the inguinal lymph nodes is crucial in disease management. Advanced stages of disease require multimodal management. Optimal sequencing of treatments and patient selection are still being investigated. Cisplatin-based chemotherapy regimens are the mainstay of systemic therapy for advanced PSCC, but they have poor and non-durable responses and high rates of toxic effects, indicating a need for the development of more effective and less toxic therapeutic options. Localized and advanced penile cancers and their treatment have profound physical and psychosexual effects on the quality of life of patients and survivors by altering sexual and urinary function and causing lymphoedema.