Indocyanine green remains in the lung for up to 6 days.

Currently there is no explicit guideline for the use of indocyanine green (ICG) in the localization of pulmonary nodules before surgery. How long ICG can remain in vivo is unknown. According to previous reports, ICG can be observed under infrared thoracoscope within 24 hours after injection. We unexpectedly found a case of a 54-year-old male who was still clearly visible under the infrared thoracoscope after 6 days of CT-guided injection of ICG. This unexpected finding suggests that the operation time can be arranged appropriately after local injection with ICG.