NEW ORLEANS – Indocyanine green (ICG) worked better than isosulfan blue for mapping sentinel lymph nodes (SLNs) in a pivotal phase 3 trial with 176 patients who had stage I endometrial or cervical cancer.
Four injections of ICG resulted in detection of 96% of the identified SLNs in these patients, including bilateral SLNs in 78% of the patients. In contrast, four injections with isosulfan blue dye led to detection of 74% of all SLNs and identified bilateral SLNs in 31% of the patients,, said at the annual meeting of the Society for Gynecologic Oncology.
Thetrial randomized 176 patients with stage I endometrial or cervical cancer at eight centers in the United States or Canada between December 2015 and May 2017. Patients first received one of the tagging agents and then the second, and then underwent mapping using white light to detect blue-tagged SLNs and near-infrared light to find green-tagged SLNs. The patients were aged 63 years on average, and 96% had endometrial cancer.
The researchers identified 279 sentinel lymph nodes that stained only green, nine SLNs that stained only blue, and 248 SLNs tagged with both dyes. They confirmed tumor cells within all nine of SLNs tagged with blue dye only, in 95% of those tagged with ICG only, and in 92% of the SLNs stained with both dyes. The isosulfan blue dye identified SLNs in two patients who did not have any SLNs detected by the ICG, whereas the ICG identified SLNs in 22 patients who did not have any SLNs detected using the blue dye. Sixteen patients had metastatic disease that had moved to 21 SLNs. The ICG system identified all 21 involved lymph nodes; the blue dye identified 13 of the 21 affected SLNs (62%).
Dr. Frumovitz and his associates designed FILM as primarily a test of noninferiority. The per-protocol analysis with 163 patients showed that ICG was noninferior to isosulfan blue (P less than .001). Once the results demonstrated noninferiority, the study protocol allowed the researchers to test for superiority in the full, intention-to-treat cohort of 176 patients. The results showed that ICG was significantly superior to isosulfan blue (P less than .001). In addition, ICG treatment produced no allergic or other adverse reactions, Dr. Frumovitz said.
Once ICG and the associated near-infrared detection camera receive FDA marketing approval, “I think this will become the standard within 5 years,” he predicted in an interview.