William G. Spies

Staging and monitoring of small cell lung cancer using [18F]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET).

Background:[18F]Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) scan is widely used for the staging evaluation of nonsmall cell lung cancer, however, its use in small cell lung cancer (SCLC) remains investigational. Patient and Methods:We designed a prospective study to evaluate the role of PET in SCLC. Patients with SCLC underwent PET scanning as well as conventional imaging before and after treatment. Results:A total of 39 PET scan examinations were performed in 21 patients with SCLC; 18 studies were performed before first-line chemotherapy and 21 studies were done during or after treatment. PET findings were compared with findings on CT scans of the chest or abdomen and bone scan. Discordant findings were detected in 14 out of 383 comparisons (4%) for 10 anatomic sites. In the thorax and the abdomen, PET agreed with CT scan in 92% to 100% of examinations assessing potential disease sites, including the contralateral chest, liver, and adrenals. PET agreed with bone scan in detecting bony lesions in 27 out of 32 imaging studies (84%): in 4 out of 5 discordant cases, PET findings were true and in 1 case indeterminate. Staging at baseline (limited, n = 6; extensive, n = 12) was identical when PET and sum of other staging procedures were compared. Response assessment was concordant between PET and CT scans in 8 of 9 patients who had evaluation before and after first-line chemotherapy. Conclusions:PET is potentially useful for the initial staging and monitoring of patients with SCLC and it may be superior to bone scan in detecting bone metastasis. The cost effectiveness of PET scan in SCLC remains to be determined.

Macronutrient absorption characteristics in humans with short bowel syndrome and jejunocolonic anastomosis: starch is the most important carbohydrate substrate, although pectin supplementation may modestly enhance short chain fatty acid production and fluid absorption.

BACKGROUND Diet may play an important role in the management of patients with short bowel syndrome who have colon in continuity. However, macronutrient absorption has not been well characterized, and the most appropriate dietary constituents have not been well defined. OBJECTIVE To define carbohydrate absorption characteristics in patients with short bowel syndrome and determine the potential role of pectin as a dietary substrate. METHODS The authors studied the effect of a custom pectin-based supplement in 6 subjects (3 male/3 female) aged 29-67 years with jejunocolonic anastomosis, 4 of whom required long-term parental nutrition. Small intestinal absorption capacity, macronutrient and fluid balance, gastrointestinal transit time, and energy consumption were measured. RESULTS Data showed that 53% nitrogen, 50% fat, and 32% total energy were malabsorbed. In contrast, the majority (92%) of total carbohydrate was utilized. Fecal short-chain fatty acids (SCFAs) were increased, an indication of increased fermentation. Although only 4% of starch was recovered in stool, it is indicative of considerable starch malabsorption, thus providing the main carbohydrate substrate, for colonic bacterial fermentation. In contrast, nonstarch polysaccharide was a relatively minor fermentation substrate with only 49% utilized. Eighty percent of the pectin was fermented. Supplementation was associated with increased total SCFAs, acetate, and propionate excretion. There was a trend observed toward greater fluid absorption (-5.9% ± 54.4% to 26.9% ± 25.2%) following pectin supplementation. Nonsignificant increases in gastric emptying time and orocolonic transit time were observed. CONCLUSION Despite malabsorption, starch is the primary carbohydrate substrate for colonic bacterial fermentation in patients with short bowel syndrome, although soluble fiber intake also enhances colonic SCFA production.

Usefulness of single-photon emission computed tomography of thallium-201 uptake after dipyridamole infusion for detection of coronary artery disease

The diagnostic performance of single-photon emission computed tomography (SPECT) and planar imaging of thallium-201 uptake for the detection of coronary artery disease (CAD) was compared in 79 patients who underwent both dipyridamole thallium-201 scintigraphy and coronary angiography. Clinical subgroups were assigned by severity of CAD, presence of a prior myocardial infarction and the number of narrowed coronary arteries. The overall detection of CAD was 89% for SPECT and 67% for planar (p less than 0.001). For the anterior vascular territory, sensitivities for SPECT and planar imaging were 69 and 44% (p less than 0.01), respectively; for the posterior vascular territory, sensitivities were 80 and 54% (p less than 0.01). Receiver-operating characteristic analysis, using a 5-point evaluation scale, was performed for the anterior and posterior vascular territories. Receiver-operating characteristic curves generated for SPECT and planar studies demonstrated improved diagnostic performance by SPECT in the anterior vascular territory, but showed similar performance in the posterior territory because of lower SPECT specificity despite higher sensitivity at clinically relevant decision thresholds. In each clinical subgroup of patients, the detection of CAD by SPECT was significantly superior to that by planar imaging, regardless of the severity of stenosis or the number of significantly narrowed coronary arteries, or whether a myocardial infarction was present. Thus, SPECT thallium-201 scintigraphy is an important and necessary clinical tool for detecting CAD after dipyridamole infusion.

The Novel Expanded Porphyrin, Motexafin Gadolinium, Combined with [90Y]Ibritumomab Tiuxetan for Relapsed/Refractory Non-Hodgkin's Lymphoma: Preclinical Findings and Results of a Phase I Trial

Purpose: Therapeutic strategies to enhance the efficacy of radioimmunotherapy have not been explored. Motexafin gadolinium is a novel anticancer agent that targets redox-dependent pathways and enhances sensitivity of tumor cells to ionizing radiation. Experimental Design: We did preclinical studies examining motexafin gadolinium combined with rituximab and/or radiation in lymphoma cells. We subsequently completed a phase I clinical trial combining escalating doses of motexafin gadolinium concurrently with standard [90Y]ibritumomab tiuxetan for patients with relapsed/refractory non-Hodgkins lymphoma. Results: In HF1 lymphoma cells, motexafin gadolinium and rituximab resulted in synergistic cytotoxicity (combination index, 0.757) through a mitochondrial-mediated caspase-dependent pathway, whereas cell death in Ramos and SUDHL4 cells was additive. Motexafin gadolinium/rituximab combined with radiation (1-3 Gy) resulted in additive apoptosis. Twenty-eight of 30 patients were evaluable on the phase I clinical trial. Median age was 65 years (47-87 years), and histologies were marginal-zone (n = 1), mantle-cell (n = 3), diffuse large cell (n = 6), and follicular lymphoma (n = 18). Of all patients, 86% were rituximab refractory. Therapy was well tolerated, and no dose-limiting toxicity was seen. Overall response rate was 57% [complete remission (CR), 43%], with median time–to–treatment failure of 10 months (1-48+ months) and median duration-of-response of 17 months. Of note, all responses were documented at 4 weeks. Furthermore, in rituximab-refractory follicular lymphoma (n = 14), overall response rate was 86% (CR, 64%), with a median time–to–treatment failure of 14 months (2-48+ months). Conclusions: This represents the first report of a novel agent to be combined safely concurrently with radioimmunotherapy. Furthermore, tumor responses with [90Y]ibritumomab tiuxetan/motexafin gadolinium were prompt with a high rate of CRs, especially in rituximab-refractory follicular lymphoma. (Clin Cancer Res 2009;15(20):6462–71)

Technetium-99m sulfur colloid scanning and correlative magnetic resonance imaging in patients with hairy cell leukemia and hypocellular bone marrow biopsies after 2-chlorodeoxyadenosine.

It has been observed that some patients in complete remission (CR) after 2-chlorodeoxyadenosine (2-CdA) for hairy cell leukemia (HCL) have hypocellular bone marrow biopsies despite normal peripheral blood cell counts. This discrepancy between bone marrow cellularity and peripheral blood cell counts suggests the possibility of abnormal sites of hematopoiesis. To determine sites of hematopoiesis, 11 radionuclide scans using technetium-99m (99mTc) sulfur colloid were performed in eight patients. Although no single, pattern was observed on the 99mTc sulfur colloid scans, two of the eight patients, both with virtually aplastic marrows, had multiple areas of increased uptake in the distal appendicular skeleton, suggesting abnormal sites of hematopoiesis. The same two patients had magnetic resonance imaging (MRI), which confirmed the abnormal sites of hematopoiesis.

Stability of radioiodinated monoclonal antibodies: In vitro storage and plasma analysis

The in vitro stability and immunointegrity of four radioiodinated monoclonal antibodies was evaluated in various storage conditions and also in plasma samples. The monoclonal antibodies studied included T101, B72.3, Lym1, and 16.88. Stabilities of typical monoclonal antibody therapy solutions, with radioactivities ranging from 2220 to 3700 MBq (60-100 mCi) were assessed using conventional instant thin layer chromatography and size exclusion high performance liquid chromatography. Radioimmunoreactivity was assessed using a live cell attenuated cell, or mucin-linked bead assay. Results of the study demonstrated that therapy solutions were stable to degradation, if properly stored in 5 or 10% human serum albumin at 4 degrees C for the duration of the study (5 days). Minor losses in immunoreactivity were also measured in stabilized therapy solutions. When incubated in plasma samples, radioiodinated monoclonal antibodies generally remained stable for the duration of the study (3 days). However, significant decreases in immunoreactivity were measured for specific radioiodinated monoclonal antibody preparations.

Considerations for tomographic imaging of monoclonal antibodies

Monoclonal antibodies have begun to assume a significant role in clinical research. The ability to label these agents has initiated research in the areas of radioimmunodetection and radioimmunotherapy. In the case of antibodies directed against tumor antigens, imaging has been employed to help assess location and extent of disease, and to provide information and extent of disease, and to provide information concerning biodistribution to be used in subsequent dosimetric calculations. Because of the low counting statistics characteristic of such images, the use of single photon emission computed tomography (SPECT) is suggested as a potential method of improving the diagnostic yield from image data. Careful attention to acquisition parameters and image processing options is needed if these goals are to be achieved.

Nuclear medicine imaging workstations based on personal computer technology

The development of personal computer technology has resulted in extremely powerful, inexpensive computers available as consumer items. With the addition of suitable hardware for gamma camera interfacing and image display, such systems can be transformed into fully functional nuclear medicine computers capable of performing all of the acquisition and processing tasks required in a modern radioisotope imaging department. Such an approach to nuclear medicine computerization offers many advantages in terms of flexibility, speed, cost, and expandability.

A new radioisotope technique of splenic localization for radiation treatment

A new technique of splenic localization, before initiating radiation therapy in patients with Hodgkins disease, is described. We find this method of splenic localization economical and accurate.