Intraoperative lymphatic mapping in cases of midline squamous cell carcinoma

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.

Localization of the sentinel lymph node in tongue VX2 carcinoma via indirect CT lymphography combined with methylene blue dye injection

CONCLUSIONS

Indirect computed tomography lymphography (CT-LG) combined with blue dye injection can locate the sentinel lymph node (SLN) in tongue carcinoma.

OBJECTIVE

To localize the SLN in tongue VX2 carcinoma using indirect CT-LG combined with methylene blue injection.

METHODS

Eighteen rabbits were placed into three groups: metastasis, hyperplasia, and control. Indirect CT-LG was performed with an iohexol injection into the tongue submucosa. CT images were acquired at 1, 5, and 15 min after injection. Methylene blue was injected into the same area 24 h after indirect CT-LG, followed by SLN identification and histopathological examination.

RESULTS

SLNs were visualized with an identification rate of 100%. SLN location identified using CT lymphography was confirmed by methylene blue dye. Control and hyperplastic enhanced SLNs were round or oval without any filling defects. Control rabbits had enhanced SLN attenuation values of 689.2 +/- 55.4 HU, 278.4 +/- 33.5 HU, and 71.7 +/- 9.2 HU at 1, 5, and 15 min after injection, respectively. Hyperplastic rabbits had values of 877.4 +/- 69.4 HU, 352.5 +/- 43.3 HU, and 80.2 +/- 11.5 HU. Filling defects were only observed in the ipsilateral metastatic SLNs of the metastasis group. CT attenuation values of the metastatic SLNs were 687.4 +/- 55.6 HU, 535.1 +/- 86.6 HU, and 282.3 +/- 19.4 HU at 1, 5, and 15 min, respectively, after iohexol injection. Metastatic lymph node attenuation values were significantly greater than those of the control or hyperplastic nodes at 5 (p < 0.001) and 15 min (p < 0.001) after injection.

Sentinel node concept in clinically n0 laryngeal and hypopharyngeal cancer

BACKGROUND

Sentinel nodes (SNs) are the lymph nodes that directly receive lymphatic flow from a primary cancer lesion. The SN concept implies that lymphatic metastasis initially occurs at SNs. SN navigation surgery can be introduced for cancers in which the SN concept is established. In SN navigation surgery, lymph node dissection beyond SNs can be omitted if SNs are metastasis free. Although the SN concept has been investigated frequently for oral and oropharyngeal cancer, it has so far been investigated less for laryngeal and hypopharyngeal cancer. In this study, we investigated whether the SN concept is applicable for laryngeal and hypopharyngeal cancer.

METHODS

Twenty patients with T2-T4 and clinically N0 laryngeal and hypopharyngeal cancer were recruited. (99m)Tc-phytate was injected into several sites surrounding the tumor on the day before surgery. Lymphoscintigrams were acquired from at least two different viewpoints. SNs were surveyed intraoperatively, and neck dissections including at least levels II, III, and IV were performed.

RESULTS

SNs had occult metastases in five cases. In the remaining 15 cases, neither SNs nor other lymph nodes contained metastases, consistent with the SN concept. There was one false-negative case showing delayed nodal metastasis 2 years after initial surgery. The overall accuracy of the SN concept was 95%.

CONCLUSION

Our study shows that SN biopsy is a reliable strategy to determine correct lymph node status in N0 laryngeal and hypopharyngeal cancer. SN detection was valuable in evaluating the need for neck dissection, whether ipsilaterally or bilaterally.

Is routine bilateral neck dissection absolutely necessary in the management of N0 neck in patients with supraglottic carcinoma?

The supraglottic larynx has a rich lymphatic network that places patients with supraglottic laryngeal carcinomas at high risk for early dissemination of the disease into the cervical lymphatics. Therefore, elective neck treatment of clinically N0 neck in patients with supraglottic carcinomas is widely accepted as a standard approach. However, the issue whether elective neck treatment should routinely be directed on both sides of the neck is still controversial. The present study is aimed at determining whether T2-T4 stage supraglottic carcinomas require bilateral neck dissection in the management of N0 necks. We designed a prospective study on 72 patients with N0 supraglottic laryngeal carcinoma. Patients were divided into three groups according to the site and extension of the primary tumors. Group I consisted of 21 patients with lateralized (clear lateral) lesion reaching but not crossing the midline. Group II comprised 25 patients with cancer largely involving one side and crossing to the midline. Group III included 26 patients with carcinoma equally involving both sides of the larynx or growth into the midline larynx. All patients underwent bilateral lateral neck dissection in conjunction with various types of laryngectomies selected to the status of the primary. Of the 72 patients, 16 were found to have occult regional metastases in pathologic examination (9 pN1, 4 pN2b, 3 pN2c). The prevalence of occult metastases proportionally increased with T stage from 8.3 to 22.7 and 31.2%, respectively, for T2, T3 and T4. Bilateral neck metastases were found in 2 of 26 patients (7.7%) with central lesions. There was only one patient (4%) with both ipsilateral and contralateral lymph node metastasis in group II. None of the 21 patients with lateral lesion (group I) had contralateral neck metastasis. Routine bilateral elective neck dissection may not be a part of the surgical procedure in all supraglottic laryngeal carcinoma patients. Bilateral neck dissection should be preferred for cases with central tumors and lateral tumors with positive nodes in the ipsilateral side of the neck.

Head and Neck Squamous Cell Carcinoma: Sentinel Node or Selective Neck Dissection

Improved knowledge about the metastatic behavior of mucosal squamous cell cancer of the head and neck made it possible to reduce the extension of elective and even therapeutic neck dissections by sparing selected levels, thereby reducing morbidity. The diagnostic question of when to treat a clinically negative neck to avoid unnecessary overtreatment, even through selective neck dissections, might be answered with sentinel lymph node biopsy. A thorough and sophisticated evaluation of this technique is necessary when defining suited patients.