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D A Podoloff

Publications and source records attributed to D A Podoloff.

At least 37 records · Page 2Linked to original sources
PubMed1996

Evaluation of [131I]iodoerythronitroimidazole as a predictor for the radiosensitizing effect.

The aim of this study was to evaluate whether radiolabeled iodoerythronitroimidazole (IETNIM) could predict the radiosensitization effect on tumors. Tumor-bearing mice were irradiated at a dose of 25, 31 and 37 Gy after the injection of IETNIM. They were also exposed to 37 Gy radiation at 35, 70, 140 and 240 min after the i.p. injection of IETNIM. After the irradiation, tumor growth assays were conducted and the effect of IETNIM as a radiosensitizer was estimated as enhancement factor (EF). Tumor uptake was measured at 35, 70, 140 and 240 min after i.p. injection of [131I]IETNIM, which were the same intervals used in the radiosensitization study. EF of IETNIM in mice treated with 25, 30 and 37 Gy irradiation was 0.72, 0.98 and 1.28, respectively. EF of IETNIM in mice irradiated at 35, 70, 140 and 240 min after the injection was 1.50, 1.69, 1.46 and 1.08, which corresponded to the tumor uptake and blood clearance of [131I]IETNIM. [131I]IETNIM may be a suitable radiopharmaceutical to predict the radiosensitization effect of misonidazole analogs on tumors.

Animals↗
PubMed1996

99Tcm-IMMU4 imaging in recurrent colorectal cancer: efficacy and impact on surgical management.

The aims of this study were to evaluate the efficacy of scintigraphy with the 99Tcm-labelled anti-carcinoembryonic antigen (CEA) monoclonal antibody Fab' fragment (IMMU4) in the diagnosis of recurrent colorectal carcinoma and to investigate its usefulness in the intraoperative surgical management of patients undergoing re-operation because of a rising serum CEA. We evaluated 24 patients prospectively who had rising serum CEA 6-19 months after initial surgery for colorectal carcinoma. Ten patients had lesions confirmed by computed tomography, ultrasound, magnetic resonance imaging, endoscopic examination or barium enema. Fourteen patients had negative findings on one or more of the above studies, but were suspected of having occult disease from their rising serum CEA. All patients were scheduled for surgery for restaging during a "second look' procedure. Planar and single photon emission tomography (SPET) imaging was performed in all patients. All scintigraphic findings were correlated with surgical and histopathological results. The overall sensitivity, specificity and accuracy were 81, 90 and 86% respectively when analysed by lesion, and 95, 60 and 88% respectively when analysed by patient. Ten of 14 (71%) patients with occult disease were correctly diagnosed as having recurrent disease. The SPET images were shown to have superior detectability (80%) compared with the planar images (35%). The surgeon judged the study to have had a neutral impact in 75% of the patients, but to have been helpful in 25%. We conclude that this antibody is potentially useful in detecting recurrent colorectal carcinoma in patients with rising serum CEA, especially when conventional imaging is negative or equivocal. It can also be helpful in altering planned surgery.

Adenocarcinoma↗
PubMed1996

Development of new markers for hypoxic cells: [131I]Iodomisonidazole and [131I]Iodoerythronitroimidazole.

This study was aimed at developing ligands to evaluate tumor hypoxia by planar scintigraphy. Two 2-nitroimidazole analogues were developed as precursor compounds to image hypoxic tumors. Both tosylmisonidazole (Ts MISO) and tosylerythronitroimidazole (Ts ETNIM) were labeled with 131I. The biodistribution and autoradiographic evaluations by planar scintigraphy of 131I-IMISO and 131I-IETNIM were conducted at 1, 2 and 4 hours after administration to rats bearing 13762 breast tumors. Biodistribution of 131I-IMISO was also evaluated in Madison lung tumor-bearing mice. Intratumoral oxygen tension was measured by the Eppendorf system. Biodistribution showed similar tumor/blood and tumor/muscle count density ratios for both compounds. The thyroid uptake of both analogues was increased with time, suggesting in vivo deiodination probably occurred. Autoradiographs of 131I-IMISO and 131I-IETNIM revealed good visualization of the neoplasms. The tumor oxygen tension was 3-6 mmHg as compared to the normal tissue oxygenation of 30-40 mmHg. The findings indicate that these analogues can localize in the hypoxic region of solid tumors and may assist with quantitation of the hypoxic fraction of tumor for proper selection and evaluation of appropriate radiotherapy and chemotherapy.

Animals↗
PubMed1996

Evaluation of preoperative chemotherapy using PET with fluorine-18-fluorodeoxyglucose in breast cancer.

UNLABELLED: We retrospectively investigated the value of PET with fluorine-18 fluorodeoxyglucose (FDG) for preoperative chemotherapy response in patients with locally advanced breast cancer. METHODS: FDG-PET studies were performed on 16 consecutive patients. All patients had PET studies before chemotherapy, 13 patients between the end of the first cycle and at the midpoint of chemotherapy, and 14 patients before surgery. Visual diagnoses and the standardized uptake values (SUV) of PET scans were compared with pathology findings at surgery and with the results of mammography, ultrasonography (US) or both, which were performed before chemotherapy and before local surgery for residual disease. Each patient's clinical course was monitored for up to 3 yr. RESULTS: Sensitivity for detection of pathologically proven primary lesions was 100%, 62.5% and 87.5% with FDG-PET, mammography and US, respectively; and sensitivity for detection of initial nodal involvement was 77%, 70% and 87.5%, respectively. Sensitivity for detection of residual primary tumor was 75%, 71.4% and 87.5%, respectively; and sensitivity for detection of residual nodal involvement was 41.6%, 71.4% and 66.6%, respectively. The mean SUV value of primary lesions was 9.4 (range 2.0-20.7, n = 16), with only two lesions showing an SUV below 3. Clinical improvement of primary lesions was seen in all patients; improvement with smaller size and less FDG uptake was visible as early as the second study in 11 patients (69%). Mean SUV values obtained at the second and third studies decreased significantly from those obtained in the first study. In four patients, the disease recurred after breast surgery with high SUV values. The mammograms and sonograms obtained before surgery showed a decrease in the diameter of 6 and 12 primary lesions of the 13 and 14 patients examined, respectively. CONCLUSION: FDG-PET is valuable for monitoring the effects of preoperative chemotherapy in patients with locally advanced breast cancer with better sensitivity for primary tumor and better specificity for nodal metastasis in comparison with ultrasonography.

Adult↗
PubMed1996

Comparison of fluorine-18-fluorodeoxyglucose and carbon-11-methionine PET in detection of malignant tumors.

UNLABELLED: Two commonly used tumor-seeking agents for PET are 2-deoxy-2-18F-fluoro-D-glucose (FDG) and L-methyl-11C-methionine (Met). This study compared FDG and Met in detecting residual or recurrent malignant tumors in the same patients. METHODS: Thirty-four lesions in 24 patients with clinically suspected recurrent or residual tumors were studied with PET using Met as well as FDG. FDG scans were conducted 1 hr after the completion of PET with Met. The color-coded superimposed images of standardized uptake values (SUVs) and transmission data were produced, and the peak SUVs in the lesions were then evaluated. Lesions above 2.5 SUV were interpreted as positive results for active tumor. RESULTS: The sensitivity of FDG-PET and Met-PET were 64.5% (20/31 lesions) and 61.3% (19/31 lesions), respectively. The mean SUV of FDG in residual or recurrent malignant tumors (n = 31) was significantly higher than that of Met but there was a significant correlation (r = 0.788, p < 0.01) between FDG and Met SUVs in all lesions (n = 34). CONCLUSION: PET using FDG and Met appear equally effective in detecting residual or recurrent malignant tumors although FDG uptakes were slightly higher than Met uptakes. Both showed a limited diagnostic sensitivity for small (< 1.5 cm) tumors.

Adult↗
PubMed1996

Comparison of fluorine-18-FDG PET and technetium-99m-MIBI SPECT in evaluation of musculoskeletal sarcomas.

UNLABELLED: We compared the diagnostic accuracy of [18F]FDG PET and 99mTc-MIBI SPECT in musculoskeletal sarcomas. METHODS: Forty-eight patients with clinically suspected recurrent or residual musculoskeletal sarcomas were examined with both FDG-PET and MIBI-SPECT within 2 wk of each study (one follow-up study in nine patients and we follow-up studies in one patient). Imaging findings were visually inspected with grading scales in conjunction with CT and/or MRI, and count-density ratios of lesion-to-contralateral area and standard uptake values (SUVs) of FDG and MIBI in lesions were also generated. The results were correlated with histologic findings (in 51 studies) and/or long-term follow-up evaluations. RESULTS: The diagnostic sensitivities and specificities were 98% and 90% using FDG, and 81.6% and 80% using MIBI, respectively, with statistical significance in the sensitivity. The tumors were demonstrated better in FDG studies, which produced higher visual grades (2.1 versus 1.6), and the tumors showed increasing SUVs with time (from 6.3 to 7.3). Four of nine patients with positive FDG but negative MIBI scans failed to respond to multidrug therapy. CONCLUSION: FDG-PET and MIBI-SPECT are useful in differentiating active sarcomas from post-treatment changes and in evaluating therapeutic response. MIBI-SPECT and FDG-PET findings should be interpreted in con junction with CT and/or MRI. FDG-PET shows statistically significant higher sensitivity than MIBI-SPECT. A positive FDG but negative MIBI scan might suggest a multidrug resistance.

Adult↗
PubMed1995

Radioimmunoscintigraphy in the differential diagnosis of hepatic mass lesion.

A patient with suspected recurrent cancer of the colon underwent a variety of imaging procedures for the differential diagnosis of a hepatic mass lesion. Computed tomography (CT) showed a low-density lesion in the left hepatic lobe, and the initial CT-guided biopsy of the liver mass was reported to demonstrate a benign lesion. Ultrasonography (US) showed a hypoechoic lesion, and technetium-99m red blood cell (RBC) scan failed to suggest a hemangioma. However, radioimmunoscintigraphy (RIS) using 99mTc- labeled anti-carcinoembryonic antigen (CEA) monoclonal antibody clearly demonstrated increase uptake of antibody in the liver lesion. Scheduled hepatic angiography was canceled and subsequent exploratory laparotomy confirmed liver metastasis. RIS appears most helpful in the diagnosis of hepatic metastasis in patients with colorectal cancer and a rising CEA level. CT, US, and 99mTc-RBC studies for the investigation of hepatic masses are briefly discussed.

Adenocarcinoma↗
PubMed1995

In-111 DTPA Ommayagrams in leptomeningeal carcinomatosis.

Radionuclide Ommayagrams in 25 patients with leptomeningeal carcinomatosis were performed after injection of 0.5 mCl of In-111 DTPA into Ommaya shunt reservoirs to evaluate cerebrospinal fluid-shunt communication, detect the blockage of the cerebrospinal fluid pathway, evaluate the cerebrospinal fluid flow pattern, and predict the distribution of the chemotherapeutics. All results were correlated with MRI evaluations of the brain and spine, as well as clinical findings. Radionuclide Ommayagrams were found to be 73% sensitive and 100% specific in the evaluation of cerebrospinal fluid space disease. MRI of the spine and head was found to be 100% sensitive, but 86% specific for obstructive cerebrospinal fluid space disease.

Adolescent↗
PubMed1995

Comparison of nuclear bone and gallium scans in the therapeutic evaluation of bone lymphoma.

The objective of this study was to compare Tc-99m MDP bone and Ga-67 scans for the therapeutic response to bone lymphoma in 40 patients. The authors retrospectively compared 40 Tc-99m MDP bone scans and 20 Ga-67 scans before therapy, 29 bone scans and 13 Ga-67 scans during the therapy, and 33 bone scans and 15 Ga-67 scans after therapy. Tc-99m MDP and Ga-67 whole body scans were obtained within 2 weeks of each study and were graded visually (grades 1-4) in which grade 3 means similar count density to that of normal iliac alar activity on bone scans and normal liver activity on Ga-67 scans, respectively. The findings of lesion improvement during and after therapy were found in 66.0% (19 of 29) and 72.7% (24 of 33) with Tc-99m MDP bone scans, 84.6% (11 of 13) and 86.7% (13 of 15) with Ga-67 scans, respectively. The mean grades of Tc-99m MDP uptake were 3.06 before, 2.34 during, and 1.75 after therapy. The mean grades of Ga-67 uptake were 3.22 before, 1.42 during, and 1.30 after therapy. Ga-67 scans appear to be more reliable than Tc-99m MDP bone scans in evaluating the therapeutic response of bone lymphoma.

Adult↗
PubMed1995

Value of SPECT imaging of the thoracolumbar spine in cancer patients.

The purpose of this study was to evaluate the usefulness of SPECT bone imaging in targeting the precise location of vertebral abnormalities to ascertain whether such knowledge would help in differentiating between metastatic and benign lesions. SPECT images of the thoracolumbar spine in 50 patients were correlated with plain x-rays, CT, MRI, PET, and bone scans and 6-month clinical follow-ups. SPECT images revealed 110 lesions, 35 of which were metastases. Twenty-four of 25 lesions involving the vertebral body with extension into posterior elements were metastases, as well as 10 of 39 lesions found in the vertebral body and 1 of 4 found in the spinous process. All lesions limited to the anterior aspect of the vertebral body (13/13), facet joints (23/23), and intervertebral disk space (6/6) were benign. In conclusion, SPECT imaging of the thoracolumbar spine is helpful in determining the precise anatomic location of vertebral abnormalities, and knowledge of the location can be used to determine whether these abnormalities in cancer patients are benign entities or metastases.

Diagnostic Imaging↗
PubMed1995

Improved conjugate view quantitation of I-131 by subtraction of scatter and septal penetration events with a triple energy window method.

The majority of radiation absorbed dose estimates for radioimmunotherapy (RIT) with I-131 labeled antibodies have been calculated based on in vivo quantitation of activity using the conjugate view approach with planar Anger camera images. Scatter and septal penetration events contributed by a small fraction of high-energy photons emitted by I-131 with an energy exceeding 600 KeV lead to a significant degradation of I-131 images acquired with an Anger camera, which blurs the images of uptake sites and complicates the definition of background regions. The objective of this study was to evaluate a triple energy window (TEW) subtraction method that has been used to remove these interfering events from I-131 images. In the method, a primary photopeak image for I-131 is obtained after sequential subtraction of septal penetration and scatter events by using scatter multipliers derived from a photopeak window and two adjacent scatter window images. Qualitative improvement in image contrast was demonstrated with this technique, together with more accurate and reproducible quantitation for I-131 in the organs of an abdominal phantom. This TEW scatter subtraction method can be used to provide more precise dosimetry estimates for radionuclide therapy and RIT with I-131.

Abdomen↗
PubMed1995

Development of F-18-labeled fluoroerythronitroimidazole as a PET agent for imaging tumor hypoxia.

PURPOSE: To develop a hydrophilic ligand to image tumor hypoxia at positron emission tomography (PET). MATERIALS AND METHODS: Biodistribution of fluorine-18-labeled fluoroerythronitroimidazole (FETNIM) and F-18-labeled fluoromisonidazole (FMISO) was determined at PET and autoradiography in three mammary-tumor-bearing rats. The partition coefficient of FETNIM, FMISO, and misonidazole was determined. RESULTS: Biodistribution of F-18-labeled FETNIM at 1, 2, and 4 hours showed tumor-to-blood ratios of 2.29 +/- 0.599, 2.41 +/- 0.567 and 8.02 +/- 2.420, respectively, and tumor-to-muscle ratios of 0.66 +/- 0.267, 2.11 +/- 0.347, and 5.92 +/- 2.240, respectively. The tumor-to-blood count density ratio with F-18-labeled FETNIM at 4 hours after injection was significantly higher than with F-18-labeled FMISO. Autoradiographs indicated that both agents could help differentiate hypoxic versus necrotic region in the tumor. CONCLUSION: F-18-labeled FETNIM can help detect tumor hypoxia and is easier to prepare, less costly, and more hydrophilic than F-18-labeled FMISO.

Animals↗