Original Article Application of nuclear medicine to achieve less invasive surgery for malignant solid tumors in children Ryo Hotta, 1 Takumi Fujimura, 1 Naoki Shimojima, 1 Tadaki Nakahara, 2 Yasushi Fuchimoto, 3 Ken Hoshino, 1 Yasuhide Morikawa, 4 Hiroshi Matsufuji 5 and Tatsuo Kuroda 1 Departments of 1 Pediatric Surgery, 2 Radiology, Keio University School of Medicine, 3 Department of Surgery, National Center for Child Health and Development, Tokyo, 4 Department of Pediatric Surgery, International University of Health & Welfare, Tochigi, and 5 Department of Pediatric Surgery, Graduate School of Medicine, Kagoshima University, Kagoshima, Japan Abstract Background: The use of nuclear medicine for the management of malignant tumor, such as radioguided surgery and sentinel lymph node biopsy (SLNB), has been widely accepted in the adult practice. However, there are very few studies to apply those techniques for pediatric diseases. The aim of this study was to investigate the feasibility of application of nuclear medicine in surgery for neuroblastoma (NB) or rhabdomyosarcoma (RMS) in children. Methods: Radioguided surgery using 123 I-metaiodobenzylguanidine was performed on six children with NB. SLNB using technetium-labeled tin or sulfur colloid was performed on two children with perineal RMS. Histological evaluation of resected specimens was performed to determine the accuracy of intraoperative detection and SLNB. All patients were evaluated for overall survival and complications. Results: Intraoperative tumor localization using hand-held gamma probe was helpful in 85.7% of NB patients. Sensi- tivity and specificity of this technique were 81.8% and 93.3%, respectively. There were no postoperative complications, and four out of five patients with high-risk NB experienced disease-free survival (median follow up, 57 months). Sentinel lymph nodes were easily detected in patients with perineal RMS, and histological assessment revealed complete consistency with regional lymph node status. Conclusions: Nuclear medicine may have a potential application in the use of less invasive surgery for advanced NB or perineal RMS, the two most challenging pediatric malignancies. Key words children, neuroblastoma, rhabdomyosarcoma, radioguided surgery, sentinel lymph node biopsy. Nuclear medicine has been widely accepted as a powerful tool for diagnosing malignant tumors in children and a useful modality for assessing treatment outcomes. The accumulation of radioac- tive material in viable cells makes possible radioguided surgery and sentinel lymph node biopsy (SLNB). Radioguided surgery was first used for intraoperative detec- tion of parathyroid adenoma in the late 1990s. 1 Preoperative localization of diseased parathyroid glands following injection of radiotracer, combined with intraoperative detection using a hand- held gamma probe, has rapidly gained popularity because of excellent outcomes that can be achieved in a minimally invasive manner. 2 Radioguided localization of occult lesions can also be facilitated by the hand-held gamma probe; a recent meta-analysis has demonstrated easier and more accurate localization of non- palpable breast cancer in comparison with conventional tech- niques. 3 To date, a few reports describe the use of radioguided surgery in the management of neuroblastoma (NB), 4–7 including recurrent disease. 8 However, no available evidence supports the use of this technique based on long-term outcomes. SLNB was introduced in adult patients with malignant mela- noma 9 as a less invasive alternative to formal regional lymph node dissection. Detection and evaluation of the sentinel lymph node, the first node draining the primary tumor along its lym- phatic pathway, allows accurate staging without formal lymph node dissection. This technique has recently been accepted as standard practice for staging newly diagnosed and clinically non-metastatic malignant melanoma and breast cancers, as post- operative complications are significantly less likely to occur compared with extensive lymphadenectomy. 10,11 However, only a few papers have described SLNB for malignant tumors in children. 12,13 In this study, we aimed to investigate the feasibility of intraoperative application of nuclear medicine for the manage- ment of advanced NB and perineal rhabdomyosarcoma (RMS) in children. The accuracy of intraoperative detection of metastatic tumors or sentinel lymph nodes (SN) was evaluated. Medical records were reviewed retrospectively to determine overall sur- vival and morbidity of those procedures. Correspondence: Tatsuo Kuroda, MD PhD, Department of Pediatric Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Email: kuroda-t@z8.keio.jp Received 4 December 2013; revised 11 March 2014; accepted 17 April 2014. Pediatrics International (2014) 56, 896–901 doi: 10.1111/ped.12368 © 2014 Japan Pediatric Society