ABSTRACT
Iodine-131-metaiodobenzylguanidine is a recently-developed radiopharmaceutical agent for adrenal medullary scintigraphy. Twenty-one scans with 131I-metaiodobenzylguanidine were performed in 20 adults with suspected phaeochromocytomas over a four-year period. All patients previously had undergone computed tomographic scans of the abdomen and pelvis. The computed-tomographic scans were abnormal in 14 patients (16 tumours), eight (nine tumours) of whose 131I-metaiodobenzylguanidine scans gave positive results. Both types of scan gave negative results in the remaining six patients. Among 12 patients who underwent surgery or postmortem examination, the 131I-metaiodobenzylguanidine scan correctly showed eight phaeochromocytomas; six tumours that were found on computed-tomographic scans but not on 131I-metaiodobenzylguanidine scans proved not to be phaeochromocytoma. The 131I-metaiodobenzylguanidine scan probably gave a true-positive result in an additional case (surgical confirmation was not available). None of the remaining seven patients in whom the 131I-metaiodobenzylguanidine scan gave negative results has been shown to harbour a phaeochromocytoma on extended follow-up (2.5 to four years). Iodine-131-metaiodobenzylguanidine is a highly sensitive and specific agent for the localization of phaeochromocytomas. In patients with suspected phaeochromocytomas and abnormal computed-tomographic findings, 131I-metaiodobenzylguanidine permits a non-invasive, functional evaluation of the morphological abnormalities to be made. The importance of making a biochemical diagnosis of a phaeochromocytoma before attempting localization studies is emphasized.
Subject(s)
Adrenal Gland Neoplasms/diagnostic imaging , Iodobenzenes , Pheochromocytoma/diagnostic imaging , 3-Iodobenzylguanidine , Adult , Aged , Female , Humans , Iodine Radioisotopes , Male , Middle Aged , Predictive Value of Tests , Radionuclide Imaging , Tomography, X-Ray ComputedABSTRACT
Prostaglandin 15-hydroxydehydrogenase (PGDH) activity in the rabbit lung increased strikingly during pregnancy. This change did not occur in the kidney, or spleen. In the corresponding organs from the rat, PGDH activity was essentially the same in pregnant and non-pregnant animals. These results are discussed in relation to the hypothesis that the increased PGDH activity in the pregnant rabbit lung is secondary to an elevated concentration of prostaglandins in the venous blood.
