[Diagnosis and therapy of neuroectodermal tumors]

Computed tomography (CT) and 123I- or 131I-meta-iodo-benzyl-guanidine (MIBG) scintigraphy were compared for accuracy in tumor detection in 47 patients with neuroectodermal neoplasms. MIBG concentration was found in 12 of 13 pheochromocytomas, 12 of 12 neuroblastomas, 5 of 9 carcinoids, and 1 of 4 glomus tumors. MIBG uptake was not observed in medullary thyroid carcinomas, oat-cell carcinomas, Merkel tumors, 1 gastrinoma, and 2 unclassified neuroectodermal neoplasms. With regard to the different tumor manifestations, the sensitivity in detecting pheochromocytomas, neuroblastomas, and carcinoids was 87%, 77%, and 100% for CT, and 83%, 100% and 71% for MIBG scintigraphy, MIBG scintiscan was superior in the detection of small adrenal pheochromocytomas (less than 1 cm diameter) and in the depiction of small bone metastases and bone marrow infiltration from neuroblastoma. In all, 25 cycles of high-dose MIBG therapy were performed in eight patients with surgically incurable tumors (4 malignant pheochromocytomas, 1 neuroblastoma, 3 carcinoids). The total therapeutic activity applied was 3.55-43.29 GBq 131I-MIBG. Tumor kinetics of MIBG were investigated before and during treatment. One patient with metastatic pheochromocytoma has been in complete remission for a follow-up period of 36 months since completion of treatment, and another patient is in partial remission. Tumor reduction or no change was observed in four patients. Two patients died of non-concentrating recurrence and metastases.