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Biomedical subjects

L C Swayne

Publications and source records attributed to L C Swayne.

At least 55 records · Page 3Linked to original sources

SPECT anti-CEA monoclonal antibody detection of occult colorectal carcinoma metastases.

Radioimmunodetection (RAID) using Tc-99m labeled Fab' fragments of the anti-CEA monoclonal antibody IMMU-4 was performed in a 68-year-old man for preoperative evaluation of colonic metastases. Planar images at 3 and 18 hours showed uptake within known metastases in the left lobe of the liver that had been observed with CT and at surgery during the preceding month. SPECT images at 3 hours demonstrated two additional unsuspected lesions. All sites were surgically confirmed the following day using intraoperative sonographic guidance, with the smallest occult lesion measuring only 6 x 9 mm. This case illustrates the limitations of CT and surgery, the potential of RAID for the detection of occult metastases, the increased sensitivity of SPECT over planar images for detecting lesions less than 1 cm in diameter, and the value of intraoperative guidance for small nonpalpable lesions.

Aged↗

The fetal presacral pseudo-mass: a normal sonographic variant.

We examined 416 consecutive third trimester intrauterine gestations over a 4-month period and discovered 26 hypoechoic masses in the fetal presacral space (6.3% incidence). These masses varied in diameter from 15 to 30 mm (mean, 21.5 mm). All neonates were normal on follow-up examination, without evidence of any masses or neurologic deficits. The fetal rectosigmoid colon frequently is identified in the third trimester and may reach 2 to 3 cm at term. Because the prevalence of meconium-filled rectum (6.3%) exceeds that of a presacral teratoma (0.0025%), this normal anatomic variant should be considered the most common cause of a third trimester presacral "mass."

Colon, Sigmoid↗

Mediastinal mass following esophageal surgery.

In this Radiology Rounds, the authors report the computed tomographic findings of a patient with an infected esophageal mucocele that formed within one month after repair of a perforated paraesophageal hiatus hernia. The patient was a 78-year old male.

Aged↗

Clinical studies of cancer radioimmunodetection with carcinoembryonic antigen monoclonal antibody fragments labeled with 123I or 99mTc.

Seventy-three patients with diverse cancers containing carcinoembryonic antigen received 123I-labeled anti-carcinoembryonic antigen monoclonal antibody F(ab')2 fragment [38 patients], 99mTc-labeled anti-carcinoembryonic antigen monoclonal antibody Fab' fragment [23 patients], or both reagents at different times [6 patients] for evaluation of antibody targeting and imaging [radioimmunodetection (RAID)], using planar and single-photon emission computed tomography. The results indicated that antibody fragments are preferred for early tumor imaging (within 24 h). Rapid targeting and clearance from blood and normal organs of the antibody fragments (blood median t1/2 elimination of 26.5 and 13.2 h for the F(ab')2 and Fab' fragments respectively) permitted the use of short-lived radionuclides, such as 123I (13.3 h) and 99mTc (6 h), and confirmed that selective antibody accretion in tumors occurred very soon after administration, such as between 2 and 5 h. Scan interpretations at 24 h for the 123I-labeled F(ab')2 and at 2-5 h for the 99mTc-labeled Fab' revealed overall sensitivities, on a tumor site basis, of 95.9 and 94.9%, respectively. On a site basis, the overall accuracies were 94.2 and 93.8% for the 123I and 99mTc immunoconjugates, respectively. In the 6 patients studied with both radioimmunoconjugates, a high concordance in detection was found. Both imaging agents also revealed a high number of putatively new tumor sites not disclosed by other radiological methods at the time of the RAID studies, of which 40.0 and 20.5% were subsequently confirmed as tumor for the 123I and 99mTc agents, respectively, within an 11-month follow-up period. This represented 24 proven occult tumor sites in 19 patients given the 123I-immunoconjugate and 16 proven occult tumor sites in 9 patients receiving the 99mTc agent. The new lesions were found up to 17 and 7 months earlier for 123I-RAID and 99mTc-RAID, respectively, than with other detection methods. The smallest tumors identified were below 0.5 cm, especially with the 99mTc immunoconjugate and single-photon emission computed tomography imaging. The findings of this study confirm previous evidence that RAID is a safe and a potentially useful new method of cancer detection. Despite the excellent results with the 123I-F(ab')2 antibody fragment, its poor availability and high cost limit its clinical use. Therefore, the 99mTc agent, which is made by an instant, 1-step, 1-vial, direct labeling method, appears to be the method of choice for rapid and accurate detection of cancer by RAID.

Adolescent↗

Transient acute tubular dysfunction in the newborn: CT findings.

We report the CT and sonographic findings of transient acute tubular disease in a newborn infant, who was dehydrated at birth. The initial CT scan demonstrated focal areas of increased attenuation within the central portions of both kidneys, and sonography showed echogenic medullary pyramids. After adequate hydration, a follow-up examination demonstrated complete spontaneous resolution.

Humans↗

Gallbladder perforation: correlation of cholescintigraphic and sonographic findings with the Niemeier classification.

We retrospectively analyzed the cholescintigrams and sonograms of 36 consecutive patients with gallbladder perforation to (a) determine the sensitivity of each for the preoperative detection of gallbladder perforation and (b) correlate the findings with the modified Niemeier classification. Cholescintigraphic criteria of perforation (free spill, pericholecystic hepatic activity, and scintigraphic gallstone ileus sign) were detected in 14 of 28 (50%) cases, while sonographic criteria of perforation (pericholecystic fluid or pneumobilia with gallstones) were present in 18% (4 of 22) of patients (p less than 0.05). Cholescintigraphic patterns of perforation associated with the Niemeier classification were: Type I (acute free perforation), 3 of 7 scans demonstrated free spill; Type II (subacute pericholecystic abscess), 9 of 19 scans showed pericholecystic activity; and Type III (chronic cholecystoenteric fistula), 1 of 3 scans showed a scintigraphic gallstone ileus. Thus, although cholescintigraphy appears superior to sonography, both modalities are relatively insensitive for the detection of gallbladder perforation.

Adult↗

Detection of left atrial myxoma with SPECT cardiac imaging.

A 69-year-old man with a left atrial myxoma underwent a gated cardiac blood pool radionuclide study that failed to visualize the cardiac tumor on either the planar images or on the composite cineangiograms from the anterior and 45 degrees LAO projections. A nongated cardiac SPECT examination, however, easily demonstrated the atrial myxoma in its characteristic location, adjacent to the interatrial septum. SPECT dramatically improved the image contrast; provided views in transaxial, coronal, and sagittal planes; and allowed direct comparison with computed tomography. Gated cardiac SPECT may be expected to provide a more accurate analysis of the complex motion and attachment site of these intracardiac tumors, as well as a more accurate tumor volume analysis.

Aged↗

Gallium SPECT detection of neoplastic intravascular obstruction of the superior vena cava.

A rare case of an intravascular neoplastic obstruction of the superior vena cava is discussed. The lesion was detected with gallium single photon emission computed tomography (SPECT) despite a normal appearance on a concurrent radiographic CT study. A computer-generated composite SPECT-CT image confirmed the intravascular localization of the radioisotope, and a subsequent CT-guided transthoracic needle biopsy revealed a poorly differentiated adenocarcinoma.

Adenocarcinoma↗