Fluorescence guided surgery using indocyanine green for pulmonary osteosarcoma metastasectomy in pediatric patients: A feasibility study

Abstract

BackgroundIn osteosarcoma patients, resection of pulmonary metastases is considered necessary for long term survival. Radiologically detected lesions are sometimes difficult to identify intraoperatively, especially when no palpation is possible during thoracoscopy. In adults, fluorescence guided surgery (FGS) using indocyanine green (ICG) has been shown to be a safe method for intra-operative identification of pulmonary metastases of different primary tumors. Our aim is to determine the feasibility of using ICG for identification of pulmonary metastases in pediatric osteosarcoma patients. MethodsNine consecutive patients with pulmonary metastases received an intravenous dose of ICG 24 h preoperatively. We started with the adult dosage of 0.5 mg/kg and also used 1.0 mg/kg to confirm that maximum fluorescent signal was achieved. Intra-operatively and post-operatively, lesions were visualized with a near-infrared camera system. Fluorescence was quantified by calculating a tumor-to-background ratio (TBR). ResultsTwo (22%) patients underwent a thoracoscopy and seven (78%) underwent a thoracotomy. Five (56%) patients had a fluorescent metastasis during surgery. In four (44%) patients there were no fluorescent metastases. In two the metastases were necrotic. In the other two, intraoperative fluorescence was most likely hampered by the depth of the metastases. Ex vivo, all vital metastases were fluorescent and necrotic specimens were not. There was no difference between 1.0 mg/kg and 0.5 mg/kg concerning TBR. No adverse events occurred. ConclusionsICG for fluorescence guided metastasectomy of pulmonary osteosarcoma is a feasible procedure in the pediatric population. However, its additional value in intra-operative guidance still has to be investigated. Levels of evidenceLevel III evidence based on a Diagnostic test study: study without a universally applied “gold” standard.