GD2-SADA:177Lu-DOTA Complex in Patients With Solid Tumors Known to Express GD2

Who May Qualify: - Signed willing to sign a consent form from patient, legal guardian(s) and/or adolescents obtained in accordance with local regulations. Pediatric patients must provide assent as required by local regulations. - Age ≥18 years at the time of willing to sign a consent form, for High Risk Neuroblastoma \& sarcoma age ≥16 years of age at time of willing to sign a consent form/assent - Measurable disease according to RECIST 1.1 - You should be able to carry out daily activities with 0 level of ability (ECOG 0)-1 - Expected survival \>3 months - Platelet counts ≥100,000 cells/mm3 - blood count (hemoglobin) at least 9 g/dL - Adequate renal function with serum creatinine ≤1.5 mg/dL or kidney function (creatinine clearance) at least 60mL/min as calculated using the Cockcroft-Gault equation - Patient willing and able to comply with the trial protocol Who Should NOT Join This Trial: - Systemic chemotherapy, radiotherapy, immunotherapy, or major surgery administered within 3 weeks prior to the first planned dosing of the IMP per protocol - Patients receiving any other investigational therapy for their cancer within 3 weeks prior to the first planned dosing of the IMP per protocol - Ongoing radiation toxicities from prior RT therapy - Patients with a diagnosis of autoimmune conditions (where your immune system attacks your own body)s or immunodeficiencies or documented infection with human weakened immune system virus (HIV) or hepatitis B or C virus (active) - Prior treatment with anti-GD2 antibody Always talk to your doctor about whether this trial is right for you.