Use of radiotracer labeling of pulmonary nodules to facilitate excisional biopsy and metastasectomy in children with solid tumors.

PURPOSE: Excision of suspected pulmonary metastases in children is challenging in the setting of multiple nodules or nodules that are small, deep, or soft. This study describes preoperative technetium macro-aggregated albumin (Tc 99m MAA) localization of pulmonary lesions to aid in intraoperative identification and resection.

METHODS: Patients with past or present pediatric solid tumors who underwent resection of pulmonary nodules following CT-guided Tc 99m MAA labeling were identified. The primary outcomes were successful preoperative localization and subsequent resection.

RESULTS: Metastasectomy following Tc 99m MAA localization was performed 15 times in 11 patients from 2014 to 2016. Mean age was 13years; the most common diagnosis was osteosarcoma (33%). Tc 99m MAA labeling was attempted in 24 nodules with mean nodule diameter 6±5mm and mean depth from the pleural surface of 12±17mm; localization was successful in 23 nodules (96%). Subsequent resection was performed by thoracotomy in 12 cases and thoracoscopy in 3. All labeled nodules were identified intraoperatively; two were not resected and 17 of the 21 nodules resected demonstrated metastatic disease on pathology.

CONCLUSION: Tc 99m MAA labeling of pulmonary nodules in children is effective in facilitating resection of sub-centimeter intraparenchymal metastases identified on preoperative imaging. Furthermore, this technique allows for thoracoscopic metastasectomy in select patients.

TYPE OF STUDY/LEVEL OF EVIDENCE: Case Series/Level IV.