A multi‐institutional feasibility lead‐in trial of lymphatic mapping with SPECT–CT for evaluating contralateral disease in lateralized oropharynx cancer using 99m‐technetium sulfur colloid.

Background: Lymphatic mapping with SPECT–CT has been demonstrated to accurately define lymphatic drainage patterns in oropharyngeal cancer but there has yet to be a study demonstrating its feasibility across multiple institutions. Methods: Twelve adult patients with lateralized oropharyngeal carcinoma (T1‐T3) who were planned for definitive or adjuvant radiotherapy without contralateral nodal disease underwent injection of 99‐m technetium sulfur colloid followed by static planar lymphoscintigraphy to verify tracer migration, and SPECT–CT acquired at 30 ± 15 min (optional) and 3 h (±1 h) (mandatory time‐point). Results: All 12 patients completed the study with 7/12 patients having the injections performed under local anesthetic and 5 patients requiring general anesthetic. There were no tracer migration failures and there were no serious adverse events or complications encountered. Four out of 12 patients (33%) showed contralateral drainage patterns. Conclusions: Lymphatic mapping with SPECT–CT of lateralized oropharyngeal squamous cell carcinoma can be performed safely across multiple institutions. [ABSTRACT FROM AUTHOR]