Sentinel node concept in clinically n0 laryngeal and hypopharyngeal cancer

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.

Sentinel node identification in laryngeal and pharyngeal carcinoma after flexible endoscopy-guided tracer injection under topical anesthesia: A feasibility study

BACKGROUND

The aim of this study was to investigate the feasibility of flexible endoscopy-guided tracer injection for sentinel lymph node (SLN) identification in patients with laryngeal and pharyngeal carcinoma.

METHODS

Sixteen cT1-4N0-2M0 patients with laryngeal or pharyngeal carcinoma underwent intra- and peritumoral [^99m Tc]Tc-nanocolloid injections after topical anesthesia under endoscopic guidance. SPECT-CT scans were performed at two time points.

RESULTS

Tracer injection and visualization of SLNs was successful in 15/16 (94%) patients. Median number of tracer injections was 1 intratumoral and 3 peritumoral. The median duration of the endoscopic procedure including tracer injection after biopsy taking was 7 min (range 4-16 min). A total of 28 SLNs were identified which were all visualized on the early and late SPECT-CT. Most SLNs were visualized in neck levels II and III.

CONCLUSIONS

Flexible endoscopy-guided tracer injection for SLN identification is a feasible and fast procedure in laryngeal and pharyngeal carcinoma patients.

Diagnostic test accuracy of sentinel lymph node biopsy in squamous cell carcinoma of the oropharynx, larynx, and hypopharynx: A systematic review and meta-analysis

The aim of this meta-analysis was to determine the diagnostic test accuracy of sentinel lymph node biopsy (SLNB) in patients with oropharyngeal, laryngeal, and hypopharyngeal squamous cell carcinoma (SCC). For this purpose, MEDLINE, EMBASE, and Web of Science were searched from inception to March 8, 2022. Included were studies evaluating diagnostic test accuracy of SLNB to identify cervical lymph node metastases with elective neck dissection or follow-up as reference. A bivariate generalized linear mixed model approach was used for the meta-analysis. Nineteen studies were eligible, evaluating 377 cases in total. The pooled estimates of sensitivity and negative predictive value were 0.93 (95% CI: 0.86-0.96) and 0.97 (95% CI: 0.94-0.98), respectively. The excellent accuracy of SLNB justifies a place in the diagnostic workup of patients with larynx and pharynx SCC. Randomized trials are required to demonstrate oncologic safety and benefits on treatment related morbidity and quality of life when omitting elective neck treatment based on SLNB.

Unilateral versus bilateral nodal irradiation: Current evidence in the treatment of squamous cell carcinoma of the head and neck

Cancers of the head and neck region often present with nodal involvement. There is a long-standing convention within the community of head and neck radiation oncology to irradiate both sides of the neck electively in almost all cases to include both macroscopic and microscopic disease extension (so called elective nodal volume). International guidelines for the selection and delineation of the elective lymph nodes were published in the early 2000s and were updated recently. However, diagnostic imaging techniques have improved the accuracy and reliability of nodal staging and as a result, small metastases that used to remain undetected and were thus in the past included in the elective nodal volume, will now be included in high-dose volumes. Furthermore, the elective nodal areas are situated close to the parotid glands, the submandibular glands and the swallowing muscles. Therefore, irradiation of a smaller, more selected volume of the elective nodes could reduce treatment-related toxicity. Several researchers consider the current bilateral elective neck irradiation strategies an overtreatment and show growing interest in a unilateral nodal irradiation in selected patients. The aim of this article is to give an overview of the current evidence about the indications and benefits of unilateral nodal irradiation and the use of SPECT/CT-guided nodal irradiation in squamous cell carcinomas of the head and neck.

Total Laryngectomy-Still Cutting-Edge?

Surgical removal of the larynx (total laryngectomy) offers a curative approach to patients with advanced laryngeal and hypopharyngeal (squamous cell) cancer without distant metastases. Particularly in T4a carcinoma, laryngectomy seems prognostically superior to primary radio(chemo)therapy. Further relevant indications for laryngectomy include massive laryngeal dysfunction associated with aspiration and recurrence after radio(chemo)therapy, resulting in salvage surgery. The surgical procedure including neck dissection is highly standardised and safe. The resulting aphonia can be compensated by functional rehabilitation (e.g., voice prosthesis) associated with a significant quality of life improvement. This article presents an overview of indications, preoperative diagnostics, surgical procedures, including new developments (robotics), possible complications, the choice of adjuvant treatment, alternative therapeutic approaches, rehabilitation and prognosis. In summary, total laryngectomy still represents a relevant surgical procedure in modern head and neck oncology.

Novel Diagnostic Approaches for Assessment of the Clinically Negative Neck in Head and Neck Cancer Patients

In head and neck cancer, the presence of nodal disease is a strong determinant of prognosis and treatment. Despite the use of modern multimodality diagnostic imaging, the prevalence of occult nodal metastases is relatively high. This is why in clinically node negative head and neck cancer the lymphatics are treated “electively” to eradicate subclinical tumor deposits. As a consequence, many true node negative patients undergo surgery or irradiation of the neck and suffer from the associated and unnecessary early and long-term morbidity. Safely tailoring head and neck cancer treatment to individual patients requires a more accurate pre-treatment assessment of nodal status. In this review, we discuss the potential of several innovative diagnostic approaches to guide customized management of the clinically negative neck in head and neck cancer patients.

Lymphoscintigraphy for Sentinel Node Mapping in Head and Neck Cancer

The aim of this comprehensive review is to describe and analyze the role of the sentinel node mapping in head and neck cancers. For this purpose, head and neck neoplasms have been categorized in cutaneous malignancies and neoplasms of the upper aerodigestive tract. A concise description of lymphatic drainage will be the "prelude" for each section, as well as the description of the injection techniques, when specific. Concisely, the attention has been focused on detection rate of the sentinel node by lymphoscintigraphy for each cancer, and for those patients in which the sentinel lymph node has been identified, true-positives rates, false-negative rates, and overall accuracy has been pointed out. Overall, in cutaneous neoplasms of the head and neck, the detection rate is higher than 90%, however the false-negative rate is still an issue, in particular in melanoma, inducing the need for newer developments. In fact, new tracers and techniques are already available, while prospective multicenter trials exploring the outcome impact are needed in the near future. For the upper aerodigestive tract and in particular oral cavity and oropharynx, sentinel lymph node identification by lymphoscintigraphy allows avoiding unnecessary neck dissection and/or node irradiation. Even in this case, the main limit remains the risk of false-negative rates. While, for patients affected by laryngeal and hypopharyngeal cancers the data seem very limited and, although the feasibility has been demonstrated, performances of this lymphoscintigraphy still need to be confirmed by multicenter studies.

[Laryngectomy-still state of the art?]

Total laryngectomy provides a curative approach for patients with advanced laryngeal and hypopharyngeal cancer without distant metastasis. Especially in stage cT4a disease, laryngectomy is superior to primary radio(chemo)therapy in retrospective studies. Further relevant indications for the procedure are tumor-related laryngeal dysfunction such as dysphagia and aspiration, as well as cancer recurrence after primary radio(chemo)therapy. The surgical procedure is highly standardized, with an appropriate safety profile. The subsequent loss of voice must be compensated by voice rehabilitation (voice prosthesis, ructus). The current overview provides information about indications for laryngectomy, preoperative clinical diagnostics, the surgical procedure, complications, alternative treatment, rehabilitation, and prognosis. Total laryngectomy remains a standard procedure in modern head and neck oncology.

Mapping of sentinel lymph node drainage using SPECT/CT to tailor elective nodal irradiation in head and neck cancer patients (SUSPECT-2): a single-center prospective trial

Background

The majority of patients with head and neck squamous cell carcinoma (HNSCC) receive bilateral elective nodal irradiation (ENI), in order to reduce the risk of regional failure. Bilateral ENI, as compared to unilateral ENI, is associated with higher incidence of acute and late radiation-induced toxicity with subsequent deterioration of quality of life. Increasing evidence that the incidence of contralateral regional failure (cRF) in lateralized HNSCC is very low (< 10%) suggests that it can be justified to treat selected patients unilaterally. This trial aims to minimize the proportion of patients that undergo bilateral ENI, by using lymph drainage mapping by SPECT/CT to select patients with a minimal risk of contralateral nodal failure for unilateral elective nodal irradiation.

Methods

In this one-armed, single-center prospective trial, patients with primary T1-4 N0-2b HNSCC of the oral cavity, oropharynx, larynx (except T1 glottic) or hypopharynx, not extending beyond the midline and planned for primary (chemo) radiotherapy, are eligible. After ^99mTc-nanocolloid tracer injection in and around the tumor, lymphatic drainage is visualized using SPECT/CT. In case of contralateral lymph drainage, a contralateral sentinel node procedure is performed on the same day. Patients without contralateral lymph drainage, and patients with contralateral drainage but without pathologic involvement of any removed contralateral sentinel nodes, receive unilateral ENI. Only when tumor cells are found in a contralateral sentinel node the patient will be treated with bilateral ENI. The primary endpoint is cumulative incidence of cRF at 1 and 2 years after treatment. Secondary endpoints are radiation-related toxicity and quality of life. The removed lymph nodes will be studied to determine the prevalence of occult metastatic disease in contralateral sentinel nodes.

Discussion

This single-center prospective trial aims to reduce the incidence and duration of radiation-related toxicities and improve quality of life of HNSCC patients, by using lymph drainage mapping by SPECT/CT to select patients with a minimal risk of contralateral nodal failure for unilateral elective nodal irradiation.

Trial registration

ClinicalTrials.gov Identifier: NCT03968679, date of registration: May 30, 2019.

Sentinel Lymph Node-Targeted Therapy by Oncolytic Sendai Virus Suppresses Micrometastasis of Head and Neck Squamous Cell Carcinoma in an Orthotopic Nude Mouse Model

In clinical N0 (cN0) cases with head and neck squamous cell carcinoma (HNSCC), a treatment selection is still controversial: elective neck dissection or watchful waiting. We focused on sentinel lymph node (SLN)-targeted therapy using the urokinase-type plasminogen activator (uPA)-dependent oncolytic Sendai virus "BioKnife." The objectives of this study were to investigate BioKnife migration into SLNs and elucidate its antitumor effect on lymph node metastases (LNM). We established an orthotopic nude mouse model of HNSCC, with LNM being frequently induced. We inoculated HSC-3-M3, human highly metastatic tongue squamous cell carcinoma cells, in the tongue of the nude mice, and after 2 weeks, we injected BioKnife into the primary tumor. We tracked BioKnife migration into the SLNs by immunostaining, RT-PCR, and an in vivo imaging system. We also examined its antitumor effects and mechanisms through serial section analysis of lymph nodes. GFP reporter expression was clearly visible in the lymph nodes of virus groups, which corresponded to SLNs. Relative GFP mRNA was significantly increased in both the tongues and lymph nodes in the virus groups compared with that in the control group (P < 0.05). Serial section analysis showed that BioKnife infected cancer cells and exhibited significant antitumor effect against LNM compared with the control groups (P < 0.05). We detected apoptosis in LNM infected by BioKnife. BioKnife migrated into SLNs after its injection into the primary tumor and effectively suppressed LNM, suggesting that SLN-targeted therapy using BioKnife has great potential to provide a novel and promising alternative to elective neck dissection in cN0 patients with HNSCC.

SPECT/CT lymphoscintigraphy of sentinel node(s) for superselective prophylactic irradiation of the neck in cN0 head and neck cancer patients: a prospective phase I feasibility study

Background

Clinically node negative HNSCC patients have a risk ranging between 18 and 45% of occult metastases, making prophylactic irradiation mandatory. Selective irradiation of nodal target volume based on international guidelines is practice. Anyway, about half the tumours lying in an anatomical subsite known to potentially drain bilaterally effectively do so, leading to unnecessary large volume irradiation. Moreover, 15% of the tumours show drainage outside of predicted basin, increasing the risk for potential geographical misses. Three-dimensional SPECT/CT lymphoscintigraphy (LS) of sentinel node(s) may help to individualize nodal target volume selection. This prospective phase I study explores its feasibility and the dosimetric impact.

Methods

Ten cN0 HNSCC patients eligible for definitive radiotherapy were imaged with SPECT/CT after ^99mTc nanocolloid injection around the tumour. The neck levels containing up to four hottest nodes were identified and selected for prophylactic irradiation (CTVn-LS) by volumetric modulated arc therapy. A comparative virtual planning was performed with volumes selected according to international guidelines (CTVn-IG).

Results

Migration was observed in all patients (one with gamma probe only). 2.9 sentinel nodes were detected per patient on average. In some patients, accurate localization was difficult when not using thermoplastic mask for SPECT/CT. CTVn-LS was totally encompassed by CTVn-IG in all patients but one (unpredicted drainage in retropharyngeal level). On average, CTVn-LS and related planning target volumes were two times smaller than IG ones. This led to significant dose decrease in identified organs at risk as well as remaining volume at risk.

Conclusions

SPECT/CT LS is a promising tool to individualize prophylactic node CTV in cN0 HNSCC patients eligible for definitive radiotherapy. Oncological safety must be confirmed by ongoing phase II study.

Novel Indocyanine Green-Phytate Colloid Technique for Sentinel Node Detection in Head and Neck: Mouse Study

OBJECTIVE

Sentinel node navigation surgery using real-time, near-infrared imaging with indocyanine green is becoming popular by allowing head and neck surgeons to avoid unnecessary neck dissection. The major drawback of this method is its quick migration through the lymphatics, limiting the diagnostic time window and undesirable detection of downstream nodes. We resolved this problem by mixing indocyanine green (ICG) with phytate colloid to retard its migration and demonstrated its feasibility in a nude mouse study.

STUDY DESIGN

Experimental prospective animal study.

SETTINGS

Animal laboratory.

SUBJECTS AND METHODS

Indocyanine green at 3 concentrations was tested to determine the optimal concentration for sentinel lymph node detection in a mouse model. Effect of indocyanine green with phytate colloid mixture solutions was also analyzed. Indocyanine green or mixture solution at different mixing ratios were injected into the tongue of nude mice and near-infrared fluorescence images were captured sequentially for up to 48 hours. The brightness of fluorescence in the sentinel lymph node and lymph nodes further downstream were assessed.

RESULTS

Indocyanine green concentration >50 μg/mL did not improve sentinel lymph node detection. The addition of phytate colloid to indocyanine green extended the period when sentinel lymph node was detectable. Second echelon lymph nodes were not imaged in mice injected with the mixture, while these were visualized in mice injected with indocyanine green alone.

CONCLUSION

This novel technique of ICG-phytate colloid mixture allows prolonged diagnostic time window, prevention of downstream subsequent nodes detection, and improved accuracy for the detection of true sentinel lymph nodes.

Superparamagnetic iron oxide-enhanced interstitial magnetic resonance lymphography to detect a sentinel lymph node in tongue cancer patients

CONCLUSION

This is the first report on human sentinel node (SN) detection by interstitial magnetic resonance (MR) lymphography with superparamagnetic iron oxide (SPIO) in tongue cancer patients who also underwent lymphoscintigraphy. Our results indicate that further studies are warranted, as this novel method may replace current scintigraphic techniques.

OBJECTIVES

To examine the feasibility of interstitial MR lymphography using SPIO for SN detection in the head and neck region.

METHODS

MR images were acquired sequentially at 10 min, 30 min, and 24 h after submucosally injecting 0.1 ml SPIO (ferucarbotran) around the tumor in three patients with tongue cancer without cervical lymph node metastasis (clinical T2N0M0).

RESULTS

The SNs were clearly visualized in the 10 min interstitial MR lymphography images and were completely concordant with those visualized by (99m)Tc-radiocolloid lymphoscintigraphy and a gamma probe in all cases. Iron incorporation into the SNs was confirmed by pathological examination.

Diagnostic value of sentinel lymph node biopsy in head and neck cancer: a meta-analysis

This study aimed to evaluate the diagnostic reliability of sentinel lymph node biopsy in patients with squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, and larynx by reviewing the published literature. A systematic literature review was performed using MEDLINE from 1970 to 2011. With Boolean search strings, search terms included sentinel node, supraglottic, supraglottis, tongue, head and neck, oral, pharynx, laryngeal, and larynx. Additional studies were identified through article references. Duplicate data and articles were excluded based on treating institution and study inclusion time period. Additional studies were excluded if the head and neck subsite or tumor stage was not specifically identified or if the sentinel lymph node biopsy occurred in previously treated necks. All patients had sentinel lymph node biopsy performed followed by a concurrent neck dissection. Twenty-six studies met our inclusion criteria (n = 766 patients). The pooled sensitivity and negative predictive value of SLNB for all head and neck tumors was 95 % (95 % CI 91-99 %) and 96 % (95 %CI 94-99 %), respectively. The overall sensitivity and negative predictive value of SLNB in the subset of oral cavity tumors (n = 631) was 94 % (95 % CI 89-98 %) and 96 % (95 % CI 93-99 %), respectively. One-hundred percent of oropharyngeal (n = 72), hypopharyngeal (n = 5), and laryngeal (n = 58) tumor sentinel lymph biopsy results correlated with subsequent neck dissections giving a negative predictive value of 100 %, showing that, sentinel lymph node biopsy is a valid diagnostic technique to correctly stage regional metastases in patients with head and neck squamous cell carcinoma.

Sentinel node biopsy for oral and laryngopharyngeal squamous cell carcinoma: a retrospective study of 177 patients in Japan

OBJECTIVE

Sentinel node (SN) biopsy in the head and neck region has not been widely used in Japan, except at a few facilities. However, almost all these facilities perform preoperative localization and intraoperative diagnosis by frozen section analysis of SN to select patients who must undergo neck dissection in a one-stage procedure. The objective of this study was to determine the actual status of SN biopsy at those facilities in Japan that have actively conducted this procedure, and to elucidate the usefulness and drawbacks of this technique in head and neck cancer.

METHODS

We retrospectively reviewed 177 patients who had undergone SN biopsy at 7 facilities. The underlying pathology was laryngeal or hypopharyngeal cancer in 20 patients from one hospital, while the remaining 157 patients had oral cancer. Preoperative localization of SN was determined using conventional lymphoscintigraphy with or without single photon emission computed tomography with CT (SPECT-CT). Intraoperative localization and diagnosis of SN were performed by gamma probe and frozen section analysis.

RESULTS

Conventional lymphoscintigraphy detected a mean of 2.6 SNs per patient in 137 patients with oral cancer, compared to 2.7 in 71 patients using SPECT-CT and 2.9 in 154 patients using the gamma probe. No significant differences were apparent between techniques. Forty of the 520 SNs (7.7%; 33 in oral cancer and 7 in laryngeal or hypopharyngeal cancer) were pathologically positive in the final diagnosis. Of these, 3 were not processed for frozen sectioning and were diagnosed only with hematoxylin and eosin staining. Among the others, 32 (86.5%) were diagnosed intraoperatively as showing metastasis. In terms of the false-negative rate, 144 patients were determined by SN biopsy to have no positive SNs. Of these, 2 patients had non-SN metastases found in their dissected neck and 8 patients without neck dissection showed late nodal recurrence. The false-negative rate was thus 6.9%.

CONCLUSION

Frozen section analysis, particularly multislice sectioning, offers a relatively reliable intraoperative diagnostic method. We were able to perform immediate neck dissection based on the results of multislice sectioning as a single-stage procedure.

Recent advances in surgery for head and neck cancer

PURPOSE OF REVIEW

This paper reviews the advances in surgery in head and neck cancer patients.

RECENT FINDINGS

Sentinel node biopsy is a promising diagnostic technique to detect occult lymph node metastases, especially in oral carcinomas. Fludeoxyglucose-PET seems to be useful in detecting recurrent (laryngeal) carcinoma after radiotherapy. The role of fludeoxyglucose-PET to detect residual disease in the neck after radiotherapy with or without chemotherapy is not yet clear. The armamentarium of reconstructive surgery is still expanding. Endonasal endoscopic, robotic surgery and image-guided surgery are used as minimal invasive surgery in selected patients. Other advances include photodynamic therapy, ultrasonic surgery and mechanical sutures.

SUMMARY

New diagnostic techniques are used to avoid futile extensive surgery. Technical improvements have been made to treat head and neck cancer patients with minimal invasive surgery. Large prospective trials are needed to determine the indications for each technique.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.