ABSTRACT
Diagnosis and staging of neuroendocrine tumors were significantly improved by the introduction of the chromogranin Aassay in plasma or serum as a tumor marker. Most glioma are not curable by surgery, radiotherapy, or chemotherapy, and residual tumor of variable extent is left to adjuvant measures of limited efficacy. Direct intratumoral administration of radioimmunoconjugates, toxin compounds, and gene-expressing viral vectors is supposed to lead to high intratumoral doses or drug concentrations with reduced systemic toxicity. The radiopharmakon was locoregionally injected into a stereotactically inserted Port-a-cath. Diagnostic 111In-labeled DOTA-D-Phe-Tyr-Octreotide-scintigraphy following local injection displayed homogeneous to nodular intratumoral vector distribution. The occurrence of renal insufficiency in patients with kidney protection is of great concern. In peptide receptor radionuclide therapy of neuroendocrine tumors, the radiosensitive kidney is the dose-limiting organ because of high tubular reuptake of the peptide analogs after glomerular filtration and retention of the radionuclides in the tubular cells.
