Introduction: Sentinel node mapping with radioactive technetium in non-small cell lung cancer has been shown to be feasible in several single institution reports. The Cancer and Leukemia Group B designed a phase II trial to test a standardized method of this technique in a multi-institutional setting. If validated, the technique could provide a more accurate and sensitive way to identify lymph node metastases.
Methods: Patients with clinical stage I non-small cell lung cancer amenable to resection were candidates for this trial. Intraoperatively, tumors were injected with technetium sulfur colloid (0.25 mCi). The tumor and lymph nodes were measured in vivo with a hand held Geiger counter and resection of the tumor and nodes was carried out. Sentinel nodes, all other nodes and the tumor were analyzed with standard histologic assessment. Negative sentinel nodes were also evaluated with immunohistochemistry.
Results: In this phase II trial, 8 surgeons participated (1-13 patients enrolled per surgeon), and 46 patients (out of a planned 150) were enrolled. Of these, 43 patients had cancer and an attempted complete resection, and 39 patients underwent sentinel node mapping. One or more sentinel nodes were identified in 24 of the 39 patients (61.5%). The sentinel node(s) were found to be accurate (no other nodes were positive for cancer if the sentinel node was negative) in 20/24 patients (83.3%). In the overall group the sentinel node mapping procedure was found to be accurate in 20/39 patients (51.2%).
Conclusions: Intraoperative sentinel node mapping in lung cancer with radioisotope yielded lower accrual and worse accuracy than expected. The multi-institutional attempt at validating this technique was unsuccessful.