Accuracy of sentinel lymph node biopsy for inguinal lymph node staging of penile squamous cell carcinoma: systematic review and meta-analysis of the literature

Intra-operative lymphatic mapping and sentinel node biopsy in laryngeal carcinoma using radiotracer injection

OBJECTIVE

The purpose of this study was to determine the value of sentinel lymph node biopsy (SLNB) in the laryngeal SCC, using intra-operative peri-tumoral injection of Tc-99m-phytate.

METHODS

Patients with biopsy-proven squamous cell carcinoma of the larynx were included. On the day of surgery, after anesthesia induction, suspension laryngoscopy was performed to inject 74 MBq/0.4 ml Tc-99m-phytate in four aliquots into the sub-mucosal peri-tumoral location. After a 10-min wait, a portable gamma probe was used to locate sentinel nodes. Subsequently, all patients underwent laryngectomy and neck dissection. Both sentinel nodes and non-sentinel nodes were examined using hematoxylin and eosin (H&E) staining.

RESULTS

Twenty-six patients with a diagnosis of laryngeal carcinoma were included in the study. The SLN detection rate was 65.4%, with a 100% detection rate in the supraglottic region and a 52.6% detection rate for glottis/transglottic patients. Permanent pathology results showed lymph node involvement in four patients, but only one patient had a negative result in the SLNB, resulting in an overall false negative rate of 25%. The sensitivity of the SLN technique was 75% overall, 100% in the supraglottic region, and 67% in the glottis/transglottic region.

CONCLUSION

The accuracy and feasibility of SLNB may be related to the location of the tumors in the larynx. For supraglottic tumors, the technique seems to be feasible with a low false negative rate. For glottis/transglottic tumors, both the detection rate and false negative rate seem to be suboptimal. Further studies are needed to validate our results.

Near-infrared fluorescence lymph node template region dissection plus backup lymphadenectomy in open radical cystectomy for bladder cancer using an innovative handheld device: A single center experience

BACKGROUND

The extent of pelvic lymphadenectomy (PLND) as part of radical cystectomy (RC) for bladder cancer (BC) remains unclear. Sentinel-based and lymphangiographic approaches could lead to reduced morbidity without sacrificing oncologic safety.

OBJECTIVE

To evaluate the feasibility and diagnostic value of fluorescence-guided template sentinel region dissection (FTD) using a handheld near-infrared fluorescence (NIRF) camera in open radical cystectomy.

DESIGN, SETTING, AND PARTICIPANTS

After peritumoral cystoscopic injection of indocyanine green (ICG) 21 patients underwent open RC with FTD due to BC between June 2019 and June 2021. Intraoperatively, the FIS-00 Hamamatsu Photonics® NIRF camera was used to identify and resect fluorescent template sentinel regions (FTRs) followed by extended pelvic lymphadenectomy (ePLND) as oncological back-up.

OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS

Descriptive analysis of positive and negative results per template region.

RESULTS AND LIMITATIONS

FTRs were identified in all 21 cases. Median time (range) from ICG injection to fluorescence detection was 75 (55-125) minutes. On average (SD), 33.4 (9.6) lymph nodes were dissected per patient. Considering template regions as the basis of analysis, 67 (38.3%) of 175 resected regions were NIRF-positive, with 13 (7.4%) regions harboring lymph node metastases. We found no metastatic lymph nodes in NIRF-negative template regions. Outside the standard template, two NIRF-positive benign nodes were identified.

CONCLUSION

The concept of NIRF-guided FTD proved for this group all lymph node metastases to be found in NIRF-positive template regions. Pending validation in a larger collective, resection of approximately 40% of standard regions may be sufficient and may result in less morbidity.

Penile cancer care in the Netherlands: increased incidence, centralisation, and improved survival

OBJECTIVE

To evaluate penile squamous cell carcinoma (PSCC) incidence and centralisation trends in the Netherlands over the past three decades, as well as the effect of centralisation of PSCC care on survival.

PATIENTS AND METHODS

In the Netherlands PSCC care is largely centralised in one national centre of expertise (Netherlands Cancer Institute [NCI], Amsterdam). For this study, the Netherlands Cancer Registry, an independent nationwide cancer registry, provided per-patient data on age, clinical and pathological tumour staging, follow-up, and vital status. Patients with treatment at the NCI were identified and compared to patients who were treated at all other centres. The age-standardised incidence rate was calculated with the European Standard Population. The probability of death due to PSCC was estimated using the relative survival. Multivariable Cox regression analysis was performed to evaluate predictors of survival.

RESULTS

A total of 3160 patients were diagnosed with PSCC between 1990 and 2020, showing a rising incidence (P < 0.001). Annual caseload increased at the NCI (1% in 1990, 65% in 2020) and decreased at other (regional) centres (99% to 35%). Despite a relatively high percentage of patients with T2-4 (64%) and N+ (33%) at the NCI, the 5-year relative survival was higher (86%, 95% confidence interval [CI] 82-91%) compared to regional centres (76%, 95% CI 73-80%, P < 0.001). Patients with a pathological T2 tumour were treated with glans-sparing treatment more often at the reference centre than at the regional centres (16% vs 5.0%, P < 0.001). After adjusting for age, histological grading, T-stage, presence of lymph node involvement and year of diagnosis, treatment at regional centres remained a predictor for worse survival (hazard ratio 1.22, 95% CI 1.05-1.39; P = 0.006).

CONCLUSION

The incidence of PSCC in the Netherlands has been gradually increasing over the past three decades, with a noticeable trend towards centralisation of PSCC care and improved relative survival rate.

Accuracy of sentinel node mapping in Marjolin ulcer: Comparison of three different injection techniques

BACKGROUND

Marjolin ulcer is a specific type of squamous cell cancer that can benefit from the use of lymphoscintigraphy.The purpose of this study was to evaluate 3 different injection techniques for sentinel node biopsy in patients with Marjolin ulcer.

METHODS

Forty-eight patients with Marjolin ulcer (27 male and 21 female) ranging in age from 24 to 85 years were included in our study. Intratumoral (IT), peritumoral (PT) and periscar (PS) tissue injections of radiotracer were done in 9, 10, and 29 patients respectively. Injections were done 2-4 h before surgery. Lymphoscintigraphy was done for mapping the lymphatic drainage. During surgery, lymphatic mapping and sentinel node biopsy was performed using a handheld gamma probe. After harvesting sentinel nodes, regional lymph node dissection was done.

RESULT

Sentinel node detection rate was higher in the PS group as compared to the IT and PT groups (89.6% vs. 50% and 22.2%) respectively. False negative rate was 0%. Pathologically involved sentinel nodes were detected in 16% of the included patients of our study which led to management change. None of the patients with pathologically non-involved sentinel nodes developed regional lymph node recurrence.

CONCLUSION

Lymphatic mapping and sentinel node biopsy is feasible in Marjolin ulcer with high detection rate and low false negative cases which by detection of regional lymph node involvement can potentially change the management of patients. Injection site may be an important factor influencing the success of the procedure and injection of the mapping material in the peri-scar normal skin proximal to the lesion is the best technique.

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

PURPOSE

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

BACKGROUND

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

EVIDENCE ACQUISITION

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

RESULTS

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

CONCLUSION

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

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.

Diagnostic Value of the Sentinel Lymph Node Technique in Patients with Muscle-Invasive Bladder Cancer

BACKGROUND

The optimal limits of the bilateral pelvic lymph node dissection (PLND) template in bladder cancer treatment remain controversial. This study aimed to investigate whether radio-guided sentinel node (SLN) detection is a reliable technique for the perioperative localisation of potential lymphatic metastasis during cystectomy for muscle-invasive bladder cancer (MIBC).

MATERIALS AND METHODS

We studied 54 patients with pT2-pT4 MIBC who underwent cystectomy with extended PLND (ePLND) augmented by the SLN technique. The identification of SLN was performed by preoperative SPECT/CT hybrid lymphoscintigraphy using peritumoral injection of nanocolloid-Tc-99m, followed by intraoperative navigation with a handheld γ-probe. All nodal specimens were collected separately and then fixed in formalin, stained with haematoxylin and eosin, and examined by an experienced uropathologist.

RESULTS

A total of 1414 LNs were resected and examined for the presence of metastases. The mean number of harvested LNs was 26 (range: 11-50) per patient. In 51 of 54 patients, 192 SLNs were resected. In addition, 20/192 (10.4%) SLNs were located outside of the ePLND area. Overall, 72 metastatic LNs (LN+) were found in 22 of 54 patients (40.7%) and in 24/192 SLNs (12.5%). The SLN technique detected LN+ in 14 of 22 (64%) patients. The SLNs were the only sites of metastasis (SLN+ = LN+) in 6 of 22 (27.3%) LN+ patients, including two cases with foci located in the pararectal region. The diagnostic values for the sensitivity, specificity, positive predictive value, and false-negative rate for the SLN technique were 66.66%, 4.16%, 28.57%, and 33.33%, respectively. Extended lymphadenectomy and its combination with the SLN technique enabled the correct assessment in 96.3 and 100% of patients, respectively.

CONCLUSIONS

The combination of ePLND and SLN provides a better pN assessment compared to ePLND alone. Although the SLN technique has restrictions that limit its diagnostic value, its use as an addition to lymphadenectomy allows for the visualisation of nonstandard lymph drainage pathways that may be potential metastatic routes.

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 and Novel Biomarkers in Penile Carcinoma: A Prospective Review

Penile carcinoma is a rare urological neoplasia in men compared to other more common tumors, such as prostate, kidney, or bladder tumors. However, this neoplasm continues to affect a large number of patients worldwide, with developing countries presenting the highest incidence and mortality rates. Important risk factors such as the human papilloma virus, a factor affecting a large number of patients, have been described; however, few studies have evaluated screening programs in populations at risk for this disease, which severely affects the quality of life of older men. The management of these patients is usually complex, requiring surgical interventions that are not without risk and that have a great impact on the functionality of the male reproductive system. In addition, in cases of disseminated disease or with significant locoregional involvement, patients are evaluated by multidisciplinary oncological committees that can adjust the application of aggressive neoadjuvant or adjuvant chemotherapy on numerous occasions without clear improvement in survival. Chemotherapy regimens are usually aggressive, and unlike in other urological neoplasms, few advances have been made in the use of immunotherapy in these patients. The study of serological and histological biomarkers may help to better understand the underlying pathophysiology of these tumors and select patients who have a higher risk of metastatic progression. Similarly, the analysis of molecular markers will improve the availability of targeted therapies for the management of patients with disseminated disease that would benefit prognosis. Therefore, the purpose of this article is to summarize the main advances that have occurred in the development of serological and histological markers and their therapeutic implications in patients diagnosed with penile carcinoma, explaining the limitations that have been observed and analyzing future perspectives in the management of this disease.

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.

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.

Current practice patterns of society of urologic oncology members in performing inguinal lymph node staging/therapy for penile cancer: A survey study

OBJECTIVES

Inguinal lymph node (ILN) staging and therapeutic procedures are important for the diagnosis and management of suspected Inguinal lymph node metastasis in the setting of penile cancer. Morbidity associated with inguinal lymph node dissection (ILND) and the lack of standardization in its perioperative management are both significant. In this study, we aimed to define current management approaches and potential opportunities for improving outcomes.

METHODS AND MATERIALS

A questionnaire was developed with 16 questions regarding pre, peri, and postoperative management of patients undergoing ILND. The questionnaire was approved by the Society of Urologic Oncology (SUO) Questionnaire Committee, which facilitated its dissemination through an initial email and a follow-up reminder to 1,003 members. The study was conducted from July to August, 2020.

RESULTS

Of the 1,003 SUO members invited to participate, 93 responded (9.3% response rate); 49% performed 1 to 2 ILNDs annually, and 60% chose open ILND for high-risk primary cancer cN0. For suspicious lymph nodes > 2 cm, 69% preferred ILND, 86% preoperative systemic neoadjuvant chemotherapy, followed by surgery for bulky inguinal metastasis, and 84% used perioperative antibiotics (ABX), 53% of whom discontinued ABX 24 hours after surgery. Prophylactic anticoagulation was used by 78% of respondents, and 60% stopped it after ambulation. Specific ligation of lymphatics (versus none) was used by 82% of respondents, 55% obtained frozen sections, and 94% used inguinal drains. A saphenous sparing technique was used by 75% of respondents. An incisional wound vacuum device was used by 17% of respondents. Compression stockings and/or referral to a lymphedema specialist were used to manage postoperative lymphedema by 61% of respondents.

CONCLUSIONS

Responses to a penile lymphadenectomy survey were relatively low and were primarily from the academic surgeon subset of the SUO. Significant consensus ( ≥ 70%) was noted for neoadjuvant chemotherapy for bulky nodal metastasis prior to surgery, perioperative antibiotic use, ligation of lymphatics, drain placement, and saphenous sparing dissection techniques. Other evidenced-based strategies that could decrease morbidity were rarely used, including dynamic sentinel node biopsy, incisional wound vacuums, and lymphedema prevention. Prospective trials are needed to validate and resolve existing treatment paradigms and to optimize perioperative pathways to reduce complications in penile cancer management.

Inguinal lymph node dissection for penile cancer: a contemporary review

Penile cancer is an uncommon disease associated with significant psychological and physical morbidity. Penile cancer has an expectable pattern of spread in a stepwise fashion, from inguinal to pelvic lymph nodes (PLN) then distant spread. Patients with penile cancer have variable survival, with patients with a low burden of nodal metastatic disease having lasting survival with surgical management, however patients with a large amount of locoregional metastatic disease having a worse prognosis. The current management options for patients with metastatic lymph node disease in penile cancer aims to reduce the morbidity associated with radical inguinal lymph node (ILN) surgery with appropriate risk stratification to optimise oncological control of the disease. This article describes current challenges in managing the inguinal region in patients with penile squamous cell carcinoma (SCC).

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.

DaPeCa-7: comparative assessment of fluorodeoxyglucose positron emission tomography/computed tomography (CT) and conventional diagnostic CT in diagnosis of lymph node metastases, distant metastases and incidental findings in patients with invasive penile cancer

OBJECTIVES

To evaluate diagnostic accuracy of ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) compared to contrast-enhanced CT in assessment of inguinal lymph node (ILN) metastases, distant metastases and synchronous cancers in patients with penile squamous cell carcinoma (pSCC).

PATIENTS AND METHODS

During a 4-year period, patients with pSCC were scheduled for FDG PET/CT prior to surgical treatment at two referral centres that manage all penile cancers in Denmark. The primary endpoint was diagnostic accuracy of FDG PET/CT and of CT alone with histopathology or Response Evaluation Criteria In Solid Tumors (RECIST) as reference.

RESULTS

We evaluated 171 patients for distant metastases and synchronous incident cancers and examined 286 groins in 143 patients for LN metastases by FDG PET/CT. Six groins disclosed false negatives. FDG PET/CT sensitivity was 85.4% per patient. In 135 patients (270 groins), CT images were evaluated separately and 22 groins disclosed false negatives. CT sensitivity was 47.5% per patient. FDG PET/CT detected pSCC distant metastases in seven patients. Distant metastases from other cancers were newly detected in three patients. In eight patients, an incidental synchronous cancer was detected. Seven out of the 18 distant malignancies detected depended on FDG PET information.

CONCLUSION

This study underlines the increased diagnostic accuracy of FDG PET/CT compared to CT alone in the evaluation of ILN status. In patients with palpable LNs, the advantage of FDG PET/CT over CT is less pronounced. FDG PET/CT may play a role in penile cancer evaluation.

Robot-assisted endoscopic inguinal lymphadenectomy: A review of current outcomes

Objective

To review the role of robot-assisted endoscopic inguinal lymphadenectomy (RAIL) in the management of penile cancer.

Methods

A PubMed search for all relevant publications regarding RAIL series up until August 2019 was performed using the keyword “robotic”, “inguinal lymph node dissection”, and “penile cancer”. Weighted mean was calculated in the largest series for all outcomes using the number of patients included in each study as the weighting factor.

Results

We identified 23 articles, of note the three largest series that included 102, 27, and 20 RAIL in 51, 14, and 10 patients, respectively. Saphenous vein was spared in 88.93% of RAIL cases in these series and node yield was 11.42 per groin; 35.28% of patients had positive pathological nodes. The weighted mean of operative time was 87.98 min per RAIL and the estimated blood loss was 37.08 mL per patient. The mean length of hospital stay was 1.29 days and the drain was kept in place for 17.02 days; the major complication rate was only 5.31% in these series. The mean follow-up was 33.46 months with a recurrence-free survival of 96.33%.

Conclusion

The literature regarding RAIL describes promising results, although it has shorter follow-up and higher costs when compared to historically series from the open approach. Initials series reported lower cutaneous complications compared to conventional approach, without compromising oncological outcomes. However, long-term results and larger trials are crucial to validate those findings.

Sentinel lymph node biopsy in muscle-invasive bladder cancer: single-center experience

OBJECTIVE

In this study, the validity of sentinel node biopsy procedure as our index test was assessed and compared with bilateral pelvic lymphadenectomy for staging and detecting the regional lymph nodes metastasis in patients with muscle-invasive bladder cancer (MIBC).

METHODS

Consecutive series of cases with T1-T4 urothelial MIBC were included. Following the injection of radiotracer, sentinel nodes were sought using a handheld gamma probe and all hot nodes were harvested. Bilateral pelvic lymphadenectomy was done for all patients following sentinel node biopsy. The tumor specimen, sentinel nodes, and excised lymph nodes were evaluated histopathologically. Same as the other midline tumors, detection rate and false negative rates were calculated using patient basis and side basis methods.

RESULTS

By evaluating each patient as a unit of analysis, sentinel nodes were detected in 35 of 41 patients (85%), 13/16 (81%) of the neoadjuvant chemotherapy (NAC) and 22/25 (88%) of the no-neoadjuvant chemotherapy (No-NAC) participants. The false negative rate was 3/7 (42%): 1/3 (33%) for NAC, and 2/4 (50%) for No-NAC patients. By evaluating each hemipelvis as a unit of analysis, sentinel nodes were detected in 53 of 82 hemipelves (65%), 19/32 (66%) of the NAC, and 34/50 (68%) of the No-NAC hemipelves. No false-negative result was found by assessing each hemipelvis as a unit of analysis.

CONCLUSIONS

Sentinel node biopsy is a feasible method for lymph node staging in MIBC, including patients with a history of NAC. To optimize the sensitivity, the decision regarding the lymphadenectomy is best to be based on the pathological status of sentinel node harvested from each hemipelvis separately as the unilateral finding of a sentinel node, does not rule out the possibility of metastatic involvement of contralateral pelvic lymph nodes.

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.

[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.

Role of perioperative dynamic sentinel node biopsy for cN0 penile cancer management: experience from an Italian tertiary referral center

PURPOSE

Inguinal lymphadenectomy (iLAD) reduces mortality in patients with cN0 penile cancer but yields high complication rates. Thus, its prophylactic role has been questioned and dynamic sentinel node biopsy (DSNB) was introduced to select men who should undergo the procedure. Our aim was to investigate the accuracy of a contemporary DSNB cohort.

METHODS

We performed a retrospective analysis of ≥T1 or ≥G2 cN0 penile cancer undergoing perioperative DSNB from June 2009 to June 2015 at a tertiary referral center. We excluded men with <18 months follow-up or with local recurrence after primary curative treatment. Complications were graded according to the Clavien-Dindo classification.

RESULTS

Thirty-five men underwent DSNB; 85.71% had ≤T2 penile cancer with ≤G2a histology. Per groin detection rate was 80% (scintigraphy being positive bilaterally in 60% and unilaterally in 20.0%). In no cases did DSNB prolong the postoperative course compared to primary surgery. Nine men (n = 15/109 nodes removed) had positive results, 8 of whom underwent iLAD. Among negative DSNB patients, 2 developed nodal penile cancer recurrence; none of them had node biopsy due to inconclusive scintigraphy. At a median follow-up of 42 months (interquartile range 30-78 months), if considering only men with scintigraphy detected inguinal nodes, per-patient sensitivity and specificity were 50% and 80% whereas positive predictive value and negative predictive value were 25% and 92.3%, respectively.

CONCLUSIONS

Perioperative DSNB is a safe procedure, yielding promising results when performed at a tertiary referral center. Future prospective large studies are needed to investigate how to optimize detection rate and reduce false-negative rates.

Sentinel node biopsy and lymphatic mapping in penile and prostate cancer

BACKGROUND

Nodal metastases are linked to poor outcome in men with penile or prostate cancer. Early detection and resection are important for staging and for the prognosis. However, lymphadenectomy is associated with morbidity and may miss metastases when performed solely on the basis of anatomical templates.

METHODS

In this article we describe the technique and benefits of sentinel node biopsy (SNB) and provide a review of the literature.

RESULTS

Dynamic sentinel node techniques using both radioactive and optical (hybrid) tracers have been proven effective in penile cancer. For prostate cancer, SNB added to extended nodal dissection may further tailor dissection to the highly variable lymphatic drainage patterns in the pelvis. The sensitivity of SNB was found to be superior to conventional imaging methods; however, false-negative SNB procedures can occur and a complementary extensive lymphadenectomy is required to remove additional positive nodes that were not detected in the SNB template.

CONCLUSION

SNB is a standard method for early detection of nodal metastases in penile cancer and provides superior diagnostic accuracy to conventional imaging modalities in prostate cancer.

Sentinel lymph node mapping in endometrial cancer: a systematic review and meta-analysis

Endometrial cancer is the most frequent tumor in the female reproductive system, while the sentinel lymph node (SLN) mapping for diagnostic efficacy of endometrial cancer is still controversial. This meta-analysis was conducted to evaluate the diagnostic value of SLN in the assessment of lymph nodal involvement in endometrial cancer. Forty-four studies including 2,236 cases were identified. The pooled overall detection rate was 83% (95% CI: 80-86%). The pooled sensitivity was 91% (95% CI: 87-95%). The bilateral pelvic node detection rate was 56% (95% CI: 48-64%). Use of indocyanine green (ICG) increased the overall detection rate to 93% (95% CI: 89-96%) and robotic-assisted surgery also increased the overall detection rate to 86% (95% CI: 79-93%). In summary, our meta-analysis provides strong evidence that sentinel node mapping is an accurate and feasible method that performs well diagnostically for the assessment of lymph nodal involvement in endometrial cancer. Cervical injection, robot-assisted surgery, as well as using ICG, optimized the sensitivity and detection rate of the technique. Sentinel lymph mapping may potentially leading to a greater utilization by gynecologic surgeons in the future.

Hybrid intraoperative imaging techniques in radioguided surgery: present clinical applications and future outlook

PURPOSE

This review aims to summarise the hybrid modality radioguidance techniques currently in clinical use and development, and to discuss possible future avenues of research. Due to the novelty of these approaches, evidence of their clinical relevance does not yet exist. The purpose of this review is to inform nuclear medicine practitioners of current cutting edge research in radioguided surgery which may enter standard clinical practice within the next 5-10 years. Hybrid imaging is of growing importance to nuclear medicine diagnostics, but it is only with recent advances in technology that hybrid modalities are being investigated for use during radioguided surgery. These modalities aim to overcome some of the difficulties of surgical imaging while maintaining many benefits, or providing entirely new information unavailable to surgeons with traditional radioguidance.

METHODS

A literature review was carried out using online reference databases (Scopus, PubMed). Review articles obtained using this technique were citation mined to obtain further references.

RESULTS

In total, 2367 papers were returned, with 425 suitable for further assessment. 60 papers directly related to hybrid intraoperative imaging in radioguided surgery are reported on. Of these papers, 25 described the clinical use of hybrid imaging, 22 described the development of new hybrid probes and tracers, and 13 described the development of hybrid technologies for future clinical use. Hybrid gamma-NIR fluorescence was found to be the most common clinical technique, with 35 papers associated with these modalities. Other hybrid combinations include gamma-bright field imaging, gamma-ultrasound imaging, gamma-β imaging and β-OCT imaging. The combination of preoperative and intraoperative images is also discussed.

CONCLUSION

Hybrid imaging offers new possibilities for assisting clinicians and surgeons in localising the site of uptake in procedures such as in sentinel node detection.

Contemporary management of patients with penile cancer and lymph node metastasis

Penile cancer is a rare disease that causes considerable physical and psychological patient morbidity, especially at advanced stages. Patients with low-stage nodal metastasis can achieve durable survival with surgery alone, but those with extensive locoregional metastasis have overall low survival. Contemporary management strategies for lymph node involvement in penile cancer aim to minimize the morbidity associated with traditional radical inguinal lymphadenectomy through appropriate risk stratification while optimizing oncological outcomes. Modified (or superficial) inguinal lymph node dissection and dynamic sentinel lymph node biopsy are diagnostic modalities that have been recommended in patients with high-risk primary penile tumours and nonpalpable inguinal lymph nodes. In addition, advances in minimally invasive and robot-assisted lymphadenectomy techniques are being investigated in patients with penile cancer and might further decrease lymphadenectomy-related adverse effects. The management of patients with advanced disease has evolved to include multimodal treatment with systemic chemotherapy before surgical intervention and can include adjuvant chemotherapy after pelvic lymphadenectomy. The role of radiotherapy in the neoadjuvant or adjuvant setting remains largely unclear, owing to a lack of high-level evidence of possible benefits. New targeted therapies have shown efficacy in squamous cell carcinomas of other sites and might also prove effective in patients with penile cancer.

Immunohistochemical Study of Sentinel Lymph Node in Colon Cancer

Identification of sentinel lymph node (SLN) in colon cancer is very important in order to increase the accuracy of lymph node staging. The number of examined lymph nodes represents a significant predictor of survival. This study aims to show the importance of SLN histological and immunohistochemical examination in adjuvant oncological treatment. The study includes 23 patients with colon cancer (44% women and 56% men) who came in our clinic for surgical intervention. In all cases, the SLN was identified and prepared for histological examination. In 13 of the cases, micrometastases were found onhaematoxylin-eosin (HE) staining, there were 5 cases with positive immunohistochemistry using antibodies anti-p53, anti-VEGF-C, anti-CD34, and 5 cases with SLN negative both for HE and immunohistochemistry. Altogether we had a detection rate of 92%, an accuracy of 78,2%, a sensitivity of 90%, a false negative rate of 10% and a negative predictive value of 71,4%, good values according to the literature. Four (17,3%) patients had micrometastases exclusively in the sentinel lymph node, after performing additional histological examination, using multilevel section and immunohistochemistry. After assessing the SNL on our patients, we concluded that it is a reproducible practice for lymph node analysis.

[CCAFU french national guidelines 2016-2018 on penile cancer]

INTRODUCTION

The aim of this work is to establish guidelines proposed by the external genital organ group of the CCAFU for the diagnosis, treatment and follow-up of penile cancer.

MATERIAL AND METHODS

The multidisciplinary working party studied 2013 guidelines exhaustively reviewed the literature, and evaluated references and their level of proof in order to attribute grades of recommandation.

RESULTS

The most common histological type is squamous cell carcinoma. Clinical examination of the penis is usually sufficient to access local extension. It can be completed by MRI to assess deeper extension. Physical examination of both groins must evaluate inguinal regional lymph nodes involvement. In the presence of palpable lymph nodes, abdomen and pelvis computed tomography and ¹⁸F-FDG PET-CT are recommended. Sentinel lymph node biopsy is recommended in the case of penile cancer with high risk of lymph node extension with no palpable lymph nodes. Treatment of the primary tumour is usually surgical. It must be as conservative as possible while ensuring negative surgical margins. Brachytherapy or local treatment can be proposed in some cases. Bilateral inguinal lymph node areas must be systematically treated. Inguinal lymphadenectomy alone has a curative role in patients with metastatic invasion of a single node (stage pN1). In the case of more extensive lymph node involvement, multimodal management combining chemotherapy, surgery, and possibly radiotherapy has to be considered.

CONCLUSIONS

The treatment of penile cancer is usually surgical possibly in combination with chemotherapy in the presence of lymph node extension. The main prognostic factor is lymph node involvement, requiring appropriate management at the time of diagnosis.x © 2016 Elsevier Masson SAS. All rights reserved.

Pathophysiological basis of human papillomavirus in penile cancer: Key to prevention and delivery of more effective therapies

Answer questions and earn CME/CNE Squamous cell carcinoma (SCC) of the penis is a rare malignancy in the United States, with a significantly higher incidence-up to 20 to 30 times greater-in areas of Africa and South America. This can be explained in part by the significantly greater prevalence of sexually transmitted diseases among high-risk males often having unprotected sex with multiple sexual partners. Human papillomavirus (HPV) has been implicated as the infectious pathway by which several these penile neoplasms originate from precursor lesions. In this regard, a fundamental understanding of HPV in penile carcinogenesis can have meaningful implications in understanding 1) the diagnosis of HPV-related precursor penile lesions, 2) targeting HPV-specific molecular pathways, and 3) cancer prevention. Using vaccination programs not only may improve patient outcomes but also may minimize the need for highly aggressive and often debilitating surgical resection. CA Cancer J Clin 2016;66:481-495. © 2016 American Cancer Society.

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

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

Lymphatic mapping and sentinel node biopsy in ovarian tumors: a study using intra-operative Tc-99m-Phytate and lymphoscintigraphy imaging

Background

Experience on sentinel node mapping in ovarian tumors is very limited. We evaluated the sentinel node concept in ovarian tumors using intra-operativeTc-99m-Phytate injection and lymphoscintigraphy imaging.

Methods

Thirty-five patients with a pelvic mass due to an ovarian pathology were included in the study. The radiotracer was injected just after laparotomy and before removal of the tumor either beneath the normal cortex (10 patients) or in the utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum two injections of the radiotracer (25 patients). For malignant masses, the sentinel nodes were identified using a hand held gamma probe. Then standard pelvic and para-aortic lymphadenectomy was performed. In case of benign pathologies or borderline ovarian tumors on frozen section, lymphadenectomy was not performed. The morning after surgery, all patients were sent for lymphoscintigraphy imaging of the abdomen and pelvis.

Results

Sentinel node was identified only in 4 patients of the cortical injection group. At least one sentinel node could be identified in 21 patients of the sub-peritoneal group. Sentinel nodes were identified only in the para-aortic area in 21, pelvic/para-aortic areas in 2, and pelvic only area in 2 patients. Three patients had lymph node involvement and all had involved sentinel nodes (no false negative case).

Conclusion

Sentinel node mapping using intra-operative injection of the radiotracer (in the utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum) is feasible in ovarian tumors. Technical aspects of this method should be explored in larger multicenter studies in the future.

Reliability of radioisotope-guided sentinel lymph node biopsy in penile cancer: verification in consideration of the European guidelines

BACKGROUND

Lymph node (LN) staging in penile cancer has strong prognostic implications. This contrasts with the high morbidity of extended inguinal LN dissection (LND) or over-treatment of many patients. Therefore, inguinal dynamic sentinel node biopsy (DSNB) or modified LND is recommended by the European Association of Urology (EAU) guidelines to evaluate the nodal status of patients with clinically node-negative penile cancer. This study analyzed the reliability and morbidity of radioguided DSNB in penile cancer under consideration of the current EAU recommendations in an experienced center with long-term follow-up.

METHODS

Thirty-four patients who received primary surgery and had radioguided inguinal DSNB for penile cancer (≥ T1G2) were included (July 2004 to July 2013). Preoperative sentinel LN (SLN) mapping was performed using lymphoscintigraphy after peritumoral injection of (99m)Technetium nanocolloid on the day of surgery. During surgery, SLNs were detected using a gamma probe. According to the EAU guidelines, a secondary ipsilateral radical inguinal LND was performed in patients who had positive SLNs. The false-negative and complication rates of DSNB were assessed.

RESULTS

A total of 32 patients were analyzed. Two patients were lost to follow-up. A total of 166 SLNs (median, 5; range, 1-15) were removed and 216 LNs (SLNs + non-SLNs; median, 6; range, 2-19) were dissected. LN metastases were found in five of the 32 (15.6 %) patients and nine of the 166 (5.4 %) SLNs were found to contain metastases. None of the remaining 50 non-SLNs contained metastases. In only one of the five SLN-positive patients, a singular further metastasis was detected by secondary radical inguinal LND. During follow-up (median, 30.5; range, 5-95 months) no inguinal nodal recurrence was detected. DSNB-related complications occurred in 11.1 % of explored groins.

DISCUSSION AND CONCLUSIONS

Radioguided DSNB is a suitable procedure for LN staging in penile cancer considering the EAU recommendations and with the required experience. Under these circumstances, patients can be spared from higher morbidity without compromising the detection of LN metastases or therapeutic implications. Improvement of the methodology used to perform DSNB should be developed further to decrease the risk of missing LN metastases and to simplify the procedure.

Lymphadenectomy for testicular, penile, upper tract urothelial and urethral cancers

PURPOSE OF REVIEW

The lymph node dissection (LND) is an integral component of many oncologic surgeries. Better understanding of each cancer's behaviour and improvements in surgical techniques necessitate a critical analysis of lymph node disease and the optimal LND template. This review will focus on updates in managing lymph node disease in testicular, penile, upper tract urothelial and urethral cancer.

RECENT FINDINGS

For testicular and penile cancer, advances have focused on reducing the morbidity associated with the standard templates of dissection while maintaining oncologic efficacy. For upper tract urothelial carcinoma, data continue to be mixed regarding the need for a LND, though it does seem to benefit patients with advanced tumours. Little is known regarding the optimal LND template for urethral cancer.

SUMMARY

A thorough LND has an established diagnostic and therapeutic role in testicular and penile cancer. For upper tract urothelial carcinoma, the role of an LND remains controversial, though emerging evidence points to an association with improved outcomes. Due to the rarity of urethral cancer, there are no standard LND templates, though excising clinically positive nodes is recommended. For all these cancers, more sophisticated risk stratification based upon clinical and pathologic factors has helped determine which patients require an LND and how to best manage these patients after surgery.