M. W. Groch

Bone scanning in pregnant patients with breast carcinoma.

Radionuclide scanning is usually contraindicated in pregnancy because of the danger of fetal radiation exposure. Radionuclide bone scanning with Tc–99m MDP is a sensitive indicator of early osseous metastases in breast cancer. Three cases of breast cancer during pregnancy are reported; modified bone scanning was utilized for staging and decision analysis. Modifications of bone scanning techniques to minimize fetal radiation exposure and fetal dosimetry calculations are described.

A Radioimmunoimaging and MIRD Dosimetry Treatment Planning Program for Radioimmunotherapy

A treatment planning program for radioimmunotherapy employing quantitative Anger camera imaging and the MIRD formalism has been designed and implemented on a clinical nuclear medicine computer. Radionuclide residence times are calculated from linear, mono- and bi-exponential, and cubic spline fits to regional activity versus time curves, and radiation-absorbed dose estimates for all target organs for 131I, 67Cu, and 58 other radionuclides can be calculated. This software has been successfully applied to radioimmunotherapy of B-cell malignancies and breast adenocarcinomas.

Phase I/II trial of combined 131I anti‐CEA monoclonal antibody and hyperthermia in patients with advanced colorectal adenocarcinoma

This pilot project was undertaken to evaluate the toxicity of and tumor response to combined 131I anti–carcinoembryonic antigen monoclonal antibody (131I anti‐CEA RMoAb) and hyperthermia in patients with metastatic colorectal adenocarcinoma.

Quantitative gated blood pool SPECT for the assessment of coronary artery disease at rest

BackgroundPlanar gated blood pool imaging (GBPI) has long proven to be useful for the noninvasive assessment of ventricular function. From a practical viewpoint, gated blood pool single photon emission computed tomography (GBPS) acquisition can be accomplished in the same time as a three-view planar series, with the benefit of a tomographic perspective that avoids chamber overlap.Methods and ResultsQuantitative gated blood pool SPECT was applied to 10 patients who underwent coronary arteriography, contrast ventriculography, and planar gated blood pool imaging. For each patient, the mid-short axis oblique slice was divided into 4 discrete segments using 4 different reference models and 2 forms of segmentation. A center of mass (counts) fixed in the end-diastolic frame and segmentation that bisected the ventricular septum proved to have the highest sensitivity and specificity for determining regional wall motionormalities at rest in myocardium supplied by severely diseased coronary arteries (>75%). GBPS correctly identified 19 of 21 abnormal segments (90%), with good specificity (95%), whereas ventriculography identified 12 (57%) and planar GBPI identified 9 (43%) of the segments supplied by diseased coronaries.ConclusionQuantitative GBPS appears to be a sensitive method for assessing coronary artery disease at rest in myocardium perfused by severely diseased coronary arteries.

Validation of a knowledge-based boundary detection algorithm: a multicenter study

A completely operator-independent boundary detection algorithm for multigated blood pool (MGBP) studies has been evaluated at four medical centers. The knowledge-based boundary detector (KBBD) algorithm is nondeterministic, utilizing a priori domain knowledge in the form of rule sets for the localization of cardiac chambers and image features, providing a case-by-case method for the identification and boundary definition of the left ventricle (LV). The nondeterministic algorithm employs multiple processing pathways, where KBBD rules have been designed for conventional (CONV) imaging geometries (nominal 45° LAO, nonzoom) as well as for highly zoomed and/or caudally tilted (ZOOM) studies. The resultant ejection fractions (LVEF) from the KBBD program have been compared with the standard LVEF calculations in 253 total cases in four institutions, 157 utilizing CONV geometry and 96 utilizing ZOOM geometries. The criteria for success was a KBBD boundary adequately defined over the LV as judged by an experienced observer, and the correlation of KBBD LVEFs to the standard calculation of LVEFs for the institution. The overall success rate for all institutions combined was 99.2%, with an overall correlation coefficient ofr=0.95 (P<0.001). The individual success rates and EF correlations (r), for CONY and ZOOM geometers were: 98%,r=0.93 (CONV) and 100%,r=0.95 (ZOOM). The KBBD algorithm can be adapted to varying clinical situations, employing automatic processing using artificial intelligence, with performance close to that of a human operator.