Intraoperative sentinel lymph node mapping in non-small-cell lung cancer improves detection of micrometastases.
OBJECTIVE
Lymph node metastases are the most significant prognostic factor in localized non-small-cell lung cancer (NSCLC). Nodal micrometastases may not be detected with current standard histologic methods. We performed intraoperative technetium-99m ((99m)Tc) sentinel lymph node (SN) mapping in patients with resectable NSCLC. This study aimed to identify the first station of nodal drainage of operable lung cancers. Serial section histology and immunohistochemistry were used to validate the SN and to identify the presence of micrometastatic disease.


METHODS
One hundred patients with potentially resectable suspected NSCLC were enrolled. At thoracotomy, the primary tumor was injected with 0.25 to 2 mCi (99m)Tc. Intraoperative scintigraphic readings of both the primary tumor and lymph nodes were obtained with a hand-held gamma counter. Anatomic resection with a mediastinal node dissection was then performed.


RESULTS
Nine of the 100 patients did not have NSCLC (seven benign lesions and two metastatic tumors) and were excluded. Seventy-eight (86%) of 91 patients had a SN identified and a complete resection. Sixty-nine (88.5%) out of the 78 SNs were classified as true-positive with no metastases found in other intrathoracic lymph nodes without concurrent SN involvement. In nine patients, the SN was the only positive node. In seven of these nine patients, the SN was found to harbor only micrometastatic disease.


CONCLUSIONS
Intraoperative SN mapping with (99m)Tc is an accurate way to identify the first site of lymphatic tumor drainage in NSCLC. This method may also improve the precision of pathologic staging.
Liptay
Michael J
MJ
Section of Thoracic Surgery, Division of Thoracic Oncology, Radiation Medicine and Department of Pathology, Evanston Northwestern Healthcare, Northwestern University Medical School, Evanston, IL 60201, USA.
Grondin
Sean C
SC
Fry
Willard A
WA
Pozdol
Chris
C
Carson
Doreine
D
Knop
Carol
C
Masters
Gregory A
GA
Perlman
Reid M
RM
Watkin
William
W
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy; D013671:Technetium Tc 99m Sulfur Colloid
D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid