Preliminary Study Of Bronchoscopic Radioisotope Injection Technique For Detecting Non-small Lung Cancer Sentinel Lymph Node

Research background:In lung cancer, absent distal metastasis, lymphatic spread is the singlestrongest predictor of poor prognosis. As the purpose of ensuring the lymphnode situation, it is important to undergo a lymphadenectomy for patientswith non-small cell lung cancer. The systematic lymphadenectomyobviously increases risks of injury to nearby organs and extend the time ofoperation and anaesthesia and increased operation trauma. How do we notonly avoid unnecessary lymph node resection but also dissect the lymphnode with potential metastassis cancer cell? The concept of Sentinel lymphnode broaden the horizon.The identification and excision of the SLN allows the surgeon tostage the malignancy, while avoiding an extensive LN dissection andensuring lower morbidities in node-negative patients. In melanoma andbreast cancer patients, SLN biopsy has become a standard procedure. In theothers neoplasm, such as cervical carcinoma, vulvar cancer, prostatecancer and so on, the procedures for the dynamic detection of SLN are going to clarify its role in the surgical management. For the NSCLC, theearly investigations have met with success. Previous investigations showsthat the Technitium-99m sulfur colloid,Tc-99m tin colloid and Tc-99mnanocolloid could be tracers in SLN. However, few of them are focus onthe central NSCLC and endoscopical way.Objective:The aim of this study was to determine the accuracy and the role ofbronchoscopic radioisotope injection technique for detecting the sentinellymph node (SLN) in patients with non-small cell lung cancer.Methods：1. Twenty patients resectable non-small-cell lung cancer(NSCLC) wereincluded.2. A dosage of18.5~55.5MBq technetium99m sulfur colloid wasendoscopically administrated on patients before anaesthesia.3. The radioactivity of primary tumor and background was gatheredafter thoracotomy with a hand-hold gamma probe.4. Patients underwent routine lung resection and systematiclymphadenectomy.5. Radiolabeled nodes were also examined in vitro separately.6. Routine pathological examination was implemented andimmunohistochemistry (ICH) was carried out for micrometastases. Results：1. Identification of SLNs was in17patients, SLN identification rate is85%(17/20)2. In12patients, a unique SLN was identified and in3patients twoSLNs were detected, whereas in2patients, nodes from three differentstations could be classified as SLNs.3. The sensitivity and specificity would be52%(9/17) and100%(3/3)respectively.ConclusionsThe identification of sentinel lymph node using bronchoscopicradioisotope injection technique in patients with NSCLC is a reliable method.It could be a physiological way to mapping SLN.