Purpose The purpose of this study was to describe the use of lymphoscintigraphy and sentinel lymph-node biopsy (SLNB) for the management of children with melanoma and sarcomas. We report the experience of two children’s hospitals that utilize this technique to identify sentinel lymph nodes for lymph-node biopsy and dissection. Methods We identified 56 patients (median age 10.8 years) who underwent 58 lymphoscintigraphy procedures. There were 33 patients with melanoma and melanocytic lesions, and 23 with sarcomas. Results Of 58 lymphoscintigraphy procedures, sentinel lymph nodes were identified in 52 (90% success rate). Using the combination of intraoperative blue dye injection and lymphoscintigraphy, the success rate was 95% (55/58). Metastatic disease was found in 14 sentinel lymph nodes (13 patients with melanoma and melanocytic lesions, and 1 patient with rhabdomyosarcoma). Conclusion We have found that lymphoscintigraphy with SLNB is an effective method to identify patients who may benefit from more extensive lymph-node dissection and to identify those patients who are unlikely to benefit from further lymph-node exploration.

Peptide-receptor imaging and therapy with radiolabeled somatostatin analogs such as ⁶⁸Ga-DOTA-TATE and ¹⁷⁷Lu-DOTA-TATE have become an effective treatment option for SSTR-positive neuroendocrine tumors. The purpose of this study was to evaluate the correlation of somatostatin receptor-2 (SSTR2) expression with ⁶⁸Ga-DOTA-TATE uptake and ¹⁷⁷Lu-DOTA-TATE therapy in neuroblastoma (NB) xenograft models. We demonstrated variable SSTR2 expression profiles in eight NB cell lines. From micro-PET imaging and autoradiography, a higher uptake of ⁶⁸Ga-DOTA-TATE was observed in SSTR2 high-expressing NB xenografts (CHLA-15) compared to SSTR2 low-expressing NB xenografts (SK-N-BE(2)). Combined autoradiography-immunohistochemistry revealed histological colocalization of SSTR2 and ⁶⁸Ga-DOTA-TATE uptake in CHLA-15 tumors. With a low dose of ¹⁷⁷Lu-DOTA-TATE (20 MBq/animal), tumor growth inhibition was achieved in the CHLA-15 high SSTR2 expressing xenograft model. Although, in vitro, NB cells showed variable expression levels of norepinephrine transporter (NET), a molecular target for ¹³¹I-MIBG therapy, low ¹²³I-MIBG uptake was observed in all selected NB xenografts. In conclusion, SSTR2 expression levels are associated with ⁶⁸Ga-DOTA-TATE uptake and antitumor efficacy of ¹⁷⁷Lu-DOTA-TATE. ⁶⁸Ga-DOTA-TATE PET is superior to ¹²³I-MIBG SPECT imaging in detecting NB tumors in our model. Radiolabeled DOTA-TATE can be used as an agent for NB tumor imaging to potentially discriminate tumors eligible for ¹⁷⁷Lu-DOTA-TATE therapy.

MCTO is a rare disorder, caused by mutations in the MafB gene, a negative regulator of receptor activator of nuclear factor-кB ligand (RANKL). Manifestations include carpal and tarsal osteolysis and renal failure. Pathophysiology is poorly understood, and no effective treatment is available.