The efficacy and safety of m-[131I]iodobenzylguanidine ([131I]MIBG) were assessed in 15 patients with malignant pheochromocytomas in a nonrandomized, single arm trial, in which patients were treated with [131I]MIBG (SA, 740 megabequerel/mg) every 3 months. Seven of these patients had bone and soft tissue metastases, 4 had only soft metastases, and 4 had only bone metastases. The follow-up period ranged from 6-54 months; the number of doses ranged from 2-11, with 2.9 (78.4 mCi) to 9.25 gigabequerel (GBq) (250 mCi)/administration and a cumulative activity from 11.1-85.90 GBq (300-2322 mCi). The absorbed cumulative dose in tumors ranged from 12-155 Gy. A beneficial effect of the treatment was observed in 9 patients (60%). No complete remission of the disease was observed. Seven patients died during the study, among whom 4 never responded to the treatment. Seven had hormonal responses (4 complete and 3 partial), with a duration ranging from 5-48 months. Among these patients, 4 relapsed, and 3 died within 3 months. Five patients had partial tumoral responses mainly located in soft tissues and for a duration ranging from 29-54 months. All patients with a hormonal response had objective improvement in clinical status and blood pressure. There was no clear-cut relationship between the cumulative dose and the responses. The main side-effect observed in 1 patient with widespread bone metastases after three doses (12.9 GBq) was a pancytopenia, which resolved after treatment was discontinued. This study suggests that repeated [131I]MIBG treatment could be effective in patients with advanced malignant pheochromocytoma.

To evaluate the effects of congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia on subsequent lung function and development, we performed lung 133Xe ventilation and 99mTc perfusion scintigraphies in a group of infants who had undergone surgical repair of a severe left CDH with respiratory distress within the first 6 h of life. The initial lung scans performed in 15 children, 2-3 months of age, demonstrated a decreased ventilation in 7. In 9 children there was a trapping of 133Xe at the left lung base. Perfusion to the hernia side was reduced in 8 of the children. We re-evaluated 11 of these 15 patients after 1-2 years. The ventilation to the left lung was still decreased in 3, but perfusion remained decreased in 9. After 5 years, ventilation to the hernia side was normal in 4 of the 5 patients studied, whereas pulmonary blood flow was abnormal in 4. These results show a progressive improvement of ventilation with a persisting reduction of perfusion to the lung of the hernia side, suggesting a primary vascular pulmonary hypoplasia in CDH.

We evaluated the reliability of very low serum thyroglobulin (Tg) levels (less than 3 ng/ml) obtained after withdrawal of thyroid suppression therapy in 224 patients without anti-Tg antibodies, who had undergone total thyroidectomy (125 patients) or thyroidectomy followed by 1 or more courses of 131I therapy (99 patients), by performing whole body scans after a therapeutic course of 131I given at the same time of Tg measurement. In 79 patients (35%) a positive scan, associated with a very low level of Tg, was noted. The 131I uptake was limited to the thyroid bed in 60 patients, but metastases were demonstrated in 19 patients (8.5%). These results are mainly explained by the much improved performance of scintigraphy after administration of therapeutic doses of 131I. In the majority of patients, especially those whose 131I uptake was limited to the thyroid bed, further scans were negative. Therefore, in these cases, negative Tg values can generally be considered an early indication of satisfactory evolution. However, in 8.5% of all cases, very low Tg levels were associated with metastases. Thus the follow up of thyroid cancer should not rely only upon Tg determination, even after suppression therapy withdrawal.

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A prospective evaluation of conventional planar scintigraphy (PS), single photon emission computed tomography (SPECT), and transmission computed tomography (TCT) was performed in 98 patients with suspected focal hepatic disease (FHD). The three examinations were performed on the same day. TCT had slightly higher sensitivity (91%) and specificity (96%) than either PS or SPECT. The sensitivity and specificity of TCT was also higher than that of the combination of PS and SPECT, which was more accurate than either radionuclide technique alone, with a sensitivity of 85-87% and a specificity of 90%. These differences were not statistically significant. However, receiver operating characteristic (ROC) analysis showed that the performance of TCT was significantly better. The ROC curves also showed, without statistical significance, that SPECT appears to have better diagnostic accuracy than PS and that it seems desirable to complement SPECT imaging with PS views, to reduce the number of equivocal results.