CT guided injection of ^99mTc-MAA for lung nodule localization prior to VATS

CT guided technetium99m-macroaggregated albumin (^99mTc-MAA) injection for lung nodule localization prior to video-assisted thoracoscopic surgery (VATS) is employed at our institution for more than a decade. We retrospectively studied the success rate, factors that affect outcomes, and complications of this procedure.

147 patients with 164 nodules underwent this procedure before VATS. Imaging and procedure characteristics, complications of the procedure, successful intra-operative localization and wedge resection, if there was conversion of primary VATS to open thoracotomy and if so the reason, and histopathological diagnosis for each nodule were reviewed by two radiologists in consensus. In case of unsuccessful wedge resection, reasons for failure were derived from electronic medical record. The impact of nodule and procedure characteristics on successful intra-operative localization was assessed.

Excluding 9 nodules with unsuccessful localization due to non-procedure related reasons, the CT guided procedure was successful in 96.1% for intraoperative localization (149/155). Pleural leak of the radiotracer, split injection within the lobe, injection into a wrong nodule and gamma probe malfunction were primary reasons for failure. Nodule size, depth from pleura, and time between radiotracer injection and surgical incision did not impact success of the procedure. Among the 6 cases with procedure related failure, only 1 required conversion to open thoracotomy.

CT guided ^99mTc-MAA injection for intra-operative lung nodule localization is a feasible procedure with a high success rate and low complication rate. Attention to technique can potentially avoid procedure failure.