Aim: In order to depict the anatomy and improve the localization, sentinel node scintigraphy in breast cancer was combined with intravenous administration of pertechnetate. As this may reduce the detectability of weak 'hot spots', the number of lymph nodes detected at scintigraphy and at surgery in one group of patients was compared with that obtained in another group that had not received pertechnetate.
Patients and methods: The number of 'hot spots' at frontal and lateral views in 47 female patients at scintigraphy performed 2-3 h after subcutaneous injection of radiocolloid together with 25 MBq pertechnetate i.v. was compared in retrospect with that of 41 female patients who had not received pertechnetate. The number of lymph nodes detected at surgery using a hand-held gamma probe together with blue dye in the two groups was also compared. The washout kinetics of pertechnetate was studied in 10 patients.
Results: There was no difference in the number of detected lymph nodes at any comparison. The kinetics study revealed a decreasing activity with time after correction for physical decay.
Conclusion: Administration of a 25 MBq pertechnetate i.v. in order to improve the anatomical localization at sentinel node scintigraphy in breast cancer does not reduce the detectability of radioactive lymph nodes.