[en] There are approximately 51,000 new cases of non-Hodgkin lymphoma and 7,800 new cases of Hodgkin disease reported yearly. Combined, these diseases account for 23,000 deaths. As medical oncology advances, the probability of curing cancer will increase because of improvements in diagnostic and therapeutic interventions. Anatomic diagnostic studies such as computed tomography (CT) and magnetic resonance (MR) imaging are generally used to identify and stage lymphoma; however, when the involved nodes are of normal size, CT and MR imaging are incapable of helping to distinguish between normal nodes and those involved with either Hodgkin or non-Hodgkin lymphoma. The problem of differentiating active lymphoma from scar or necrosis in residual masses after radiation therapy and/or chemotherapy, especially in the thorax, has been well documented in the medical literature. Whether gallium imaging is useful in this situation has been the subject of controversy over the years, and there have been many important detours and milestones on the road to our understanding of the role that gallium-67 scintigraphy should play. 22 refs

[en] The authors performed diuretic renography in 17 patients with pelvic malignancy and urinary tract diversion. After injection of 10 mCi of Tc-99m-labeled DTPA, perfusion and dynamic images of renal function were obtained. Patients received furosemide, 0.5 mg/kg intravenously, 20-21 minutes into the study. Background subtracted whole-kidney time activity curves were generated. Studies were interpreted as normal, intermediate, or obstructed, depending on the contour of the washout phase of the renogram. In the immediate postoperative period, 82% of patients showed an intermediate pattern. In these patients with urinary diversion procedures, the standard criterion of a half-life of 10 minutes or less could not be used. Instead, serial studies over time best separated patients into three groups: normal, dilated without obstruction, and obstruction. Diuretic renography is useful in the follow-up of patients who have undergone urinary diversion procedures

[en] This paper presents a study of twenty-four patients with Hodgkin disease (HD) and 25 patients with non-Hodgkin lymphoma (NHL) who underwent single photon emission computed tomography (SPECT). Eighteen showed nonuniform distribution of colloid (ten with HD and eight with NHL). All ten patients with HD and four of the eight patients with NHL had abnormal liver chemistry findings. Nonuniformity is a frequent finding (37%) on SPECT studies. The finding is nonspecific and is not related to tumor involvement at clinical follow-up. Rather, nonuniformity is related to hepatic dysfunction in HD and to a different mechanism in NHL. No significant imaging differences are found between the groups

[en] This paper discusses forty-two bone marrow scans obtained with Tc-99m sulfur colloid (10 mCi) in 17 cancer patients with marrow dysplastic syndrome during treatment with granulocyte macrophase colony-stimulating factor (GM-CSF). Digital images of whole body and spot areas were analyzed with respect to sulfur colloid distribution during therapy cycles. Evaluation of relative activity in central or peripheral marrow, liver-spleen size, and extramedullary activity led to the following conclusions: Tc-99m sulfur colloid can be useful in following responses to GM-CSF therapy; in characterizing marrow distribution; and in guiding target sites for magnetic resonance (MR) evaluation. Correlation of specific site response with clinical outcome is underway

[en] The use of gallium-67 scanning for the diagnosis of intraabdominal infections is discussed. A negative scan does not rule out infection and a positive scan is highly suspicious especially when the clinical picture suggests infection

[en] This paper reports on recurrent brain tumors from posttreatment changes. Histologic diagnoses were 70 gliomas, 6 pituitary adenomas, 4 lymphomas, 1 gliosarcoma, 1 acoustic neuroma, metastasis from 1 neuroblastoma, 1 osteosarcoma, 1 lung tumor, and 1 ovarian tumor. Thirty-nine patients showed positive findings (increased glucose uptake). This corresponded to the clinically active tumor in 29 patients; two cases revealed gliosis histologically but no tumor. Forty-seven patients demonstrated negative findings (decreased or no glucose uptake), but 5 of them showed recurrent microscopic or low-grade tumors in the treated area. PET with (F-18) FDG is useful in the detection of metabolically active recurrent brain tumor but limited in detecting microscopic or low-grade astrocytomas

[en] The authors evaluated 25 patients with malignant brain and liver tumors using positron emission tomography (PET) performed with F-18 FDG and a Posicam 6.5 camera. Four primary and three metastatic brain tumors and 12 metastatic hepatic tumors demonstrated marked glucose uptake in active tumors. In one case with minimal glucose uptake, a gliosis was revealed in the treated brain tumor. One primary brain tumor treated with irradiation and one metastatic brain tumor treated with surgery showed no significant glucose uptake. Intraarterial injection of FDG in five patients with liver metastases showed variable enhancement of FDG uptake immediately in the lesions. F-18 FDG PET appears to be helpful in differentiating between residual or recurrent tumor and post-treatment changes in the brain and liver

[en] Two major obstacles in the development of improved methods for more accurate dose estimates for radioimmunotherapy have been the difficulty in obtaining an accurate patient-specific three-dimensional activity map in vivo and calculating the resulting absorbed dose. We propose a method for three-dimensional internal dosimetry that integrates the three-dimensional activity map from SPECT with a dose-point kernal convolution technique to provide the three-dimensional distribution of absorbed dose. Accurate activity quantitation was achieved with appropriate methods. The count density map from SPECT images was converted into an activity concentration map with a calibration phantom approach. This map was then convolved with an ¹³¹I dose-point kernel and three-dimensional fast Fourier transform to yield three-dimensional distribution of absorbed dose, which was then processed to provide the absorbed dose distribution in regions of interest. The accuracy of quantitative SPECT was validated to be within 16%. The calculated penetrating radiation absorbed dose was verified with thermoluminescent dosimeter measurements to be within 8%. With standard organs and configuration, the method calculated absorbed dose in good agreement with the MIRD formalism (less than 14%). This method overcomes the limitations of planar imaging techniques and the current routine implementation of the MIRD formalism. The results can be processed to provide the absorbed dose distribution in regions of interest and parameters for treatment optimization. Absorbed dose distribution from any plane can be graphically displayed in various ways. 53 refs., 9 figs., 3 tabs

[en] This paper compares discordant results of gallium (Ga) single photon emission CT (SPECT) and CT with clinical outcome in patients with thoracic Hodgkin disease and non-Hodgkin lymphoma. In 25 patients with bulky, well-differentiated disease, the mediastinum was divided into nodal areas in accordance with CT technique (15 areas). The authors evaluated 660 sites in 44 CT scans obtained 48-72 hours after intravenous administration of 296-370 MBq of Ga-67 followed by SPECT. CT scans were obtained by using an intravenous contrast medium and 10-mm-thick contiguous sections. The results of the studies were discordant in 105 sites. In 22 sites of active disease, Ga SPECT correctly showed active disease, but CT showed a stable or shrinking mass; in three cases of proved disease, Ga SPECT results were incorrectly negative, and CT results were positive. Among the sites where no disease was present, Ga SPECT results were correct for 53 sites in which CT results were incorrect, and SPECT results were incorrect in 27 sites that CT correctly showed as negative for disease

No abstract available