Indium-111 satumomab pendetide: the first FDA-approved monoclonal antibody for tumor imaging.

OBJECTIVE: Colon cancer is the second most common cause of cancer mortality. Ovarian cancer is the most common gynecologic malignancy cause of death in women. A labeled monoclonal antibody attaches to a tumor-associated antigen and allows these tumor masses to be imaged or treated, depending on the radionuclide used. Indium-111 satumomab pendetide was the first labeled monoclonal antibody to be approved by the Food and Drug Administration (FDA) for tumor imaging. It is reactive with most colorectal and ovarian cancers, as well as other cancers. After reading this article, the technologist will understand the FDA approval process, phase trial results, safety and adverse reactions, human antimurine antibody response, indications, imaging protocol, and strengths and weaknesses of imaging with satumomab pendetide. Representative cases are presented.

Raccoon eyes and the MIBG super scan: scintigraphic signs of neuroblastoma in a case of suspected child abuse.

The authors report on an infant suspected of having been abused, who presented with periorbital edema and ecchymoses (clinical "raccoon eyes"). The pattern of the nuclear medicine bone scan suggested neuroblastoma rather than trauma. Both the bone scan and the subsequent MIBG scan revealed multiple abnormalities, including markedly increased activity around the orbits, that we termed the scintigraphic raccoon eyes sign. In addition, the grossly abnormal MIBG scan demonstrated avid uptake of MIBG throughout the entire skeleton with essentially complete absence of visualization of the liver and heart (the MIBG super scan ). These signs have not previously been described in an infant or a child with neuroblastoma.

Krukenberg tumor and lung metastases from colon carcinoma diagnosed with F-18 FDG PET.

The authors report a case of a patient with postsurgical colorectal carcinoma and metastatic disease to the ovaries (Krukenberg tumor), the lung, and the liver first revealed by F-18 FDG PET imaging. The value of PET in a patient with an unexplained rising CEA is cited.

Indium-111 OncoScint CR/OV and F-18 FDG in colorectal and ovarian carcinoma recurrences. Early observations.

Indium-111 satumomab pendetide (In-111 OncoScint) planar and SPECT imaging and F-18 FDG positron emission tomography (PET) have been found individually to be helpful in the detection of recurrent colorectal and ovarian cancer, but have not been compared. Twelve patients who were examined for recurrent colorectal or ovarian carcinoma underwent both In-111 OncoScint imaging and F-18 FDG PET imaging. All had normal or equivocal results of CT or MR studies. Tumor detection abilities were similar in most cases. However, Oncoscint demonstrated an advantage in the detection of carcinomatosis. PET demonstrated an advantage in detecting focal tumor recurrence in one case and, not unexpectedly, in detecting liver metastases. All positive nuclear studies for tumor were found to be true-positives at pathology (7 patients), or by diagnostic new CT changes (1 patient). Finally, unreported, bone marrow, bowel, and colostomy sites appear to be normal sites of localization of F-18 FDG 1 hour after injection.

The MIBG super scan. Description and therapeutic implications.

The author reports a case of metastatic pheochromocytoma to bone imaged with 1-131 MIBG. The "MIBG super scan" pattern is described and is characterized by marked increased uptake in bone with essentially complete absence of activity in the liver and bladder. The avid bony metastases "steal" activity from the liver, as well as from the kidneys and soft tissues. This is felt to be comparable to the "super scan" in bone scintigraphy, whereby bony metastases "steal" activity from the kidneys and soft tissues.

The diagnostic value of grading hyperperfusion and the rim sign in cholescintigraphy.

Biliary scans of 84 hospitalized patients believed to likely have acute cholecystitis, including 55 scans that had a radionuclide angiography phase, were retrospectively evaluated to determine the frequency of the rim sign and hyperperfusion, and to test the hypothesis that more intense hyperperfusion or rim sign is associated with a greater severity of gallbladder pathology ("complicated" acute cholecystitis). In 65 of the 84 cases there was surgical intervention (including 43 from the 55 cases whose scans had a radionuclide angiography phase). "Complicated" acute cholecystitis was considered present if there was gangrene, perforation, empyema, necrosis, ulceration, or fibrous exudation. Each scan was evaluated for the presence of a rim sign and arterial hyperperfusion to the region of the gallbladder fossa. The intensities of these secondary signs of acute cholecystitis were then graded as "mild" or "marked." Subdividing the rim sign and hyperperfusion into a "marked" category considerably improved the specificity, positive predictive value, and likelihood ratio (positive) for the diagnosis of acute cholecystitis, but even more so for the complicated subgroup when marked hyperperfusion or marked rim sign were the criteria used for a positive study. Approximately 50% of the patients with acute cholecystitis had hyperperfusion and a rim sign, and approximately 15% had marked hyperperfusion and a marked rim sign. Of the patients with acute cholecystitis, the only ones with marked hyperperfusion or a marked rim sign were those who had complicated acute cholecystitis. The data demonstrate an association between greater intensity of the rim sign or hyperperfusion and greater severity of gallbladder pathology in patients with acute cholecystitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Unexpected pulmonary clumping of In-111 leukocytes attributable to indium oxine reagent.

Five cases of artifactual In-111 leukocyte pulmonary activity were noted at three local hospitals in a 4-day period. Based on the differences in the preparation of the final indium leukocyte product, the problem could be attributed to the indium oxine reagent in a specific lot. This artifact of multiple small foci of marked increased activity in the lungs (clumping pattern), attributable to the In-111 oxine reagent, has not been described previously.

Visualization of microscopic metastatic hepatoma to lung on gallium scintigraphy.

The author presents a case of metastatic hepatoma diagnosed at autopsy. The patient's liver had been nearly entirely replaced, and there were diffuse microscopic pulmonary metastases. Chest x-ray was normal at the time of gallium imaging for fever of unknown origin. Gallium imaging revealed a normal-appearing liver and mild, diffuse, bilateral increased uptake in the lungs. A CT scan 3 weeks before autopsy showed relatively minimal abnormality of the liver with a few areas of inhomogeneity and mild enhancement with contrast. Ultrasound-guided aspiration and liver biopsy were negative for tumor or infection. No case report or description of microscopic lung metastases from hepatoma seen with gallium was discovered in a recent literature search.

Mn (III) hematoporphyrin. A potential MR contrast agent.

Manganese (III) hematoporphyrin (MnHP), a new and stable complex, was prepared, and its toxicity and magnetic resonance (MR) imaging properties were evaluated. In tests of acute and subacute toxicity, no deaths resulted from bolus intravenous injections of 13 or 19 mumols/kg of MnHP, but there was a 33% mortality when the dose was 38 mumols/kg. Laboratory results were normal in the surviving rats. Ultraviolet- visible spectroscopy of the urine and serum of two rats injected 24 hours previously with 38 mumols/kg MnHP revealed no free HP, suggesting in vivo stability of MnHP. Finally, using a standardized imaging protocol, there was a mean increase of 37% in the liver-to-muscle intensity ratios in four rats injected 24 hours previously with 25 mumols/kg MnHP when compared to paired controls (P less than .005). In addition, obvious visual increase in the signal intensity of the liver on T1-weighted images was seen in animals tested with 13 and 19 mumols/kg of MnHP. The results suggest that further evaluation of MnHP as an MR contrast agent for the liver is warranted.