| 1. |
- Brun, Eva, et al.
(författare)
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Early prediction of treatment outcome in head and neck cancer with 2-18FDG PET
- 1997
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 36:7, s. 741-747
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Tidskriftsartikel (refereegranskat)abstract
- The development of alternative treatment regimens in clinical oncology has increased the need for early prediction of cancer therapy outcome. The aim of this study was, early in the treatment phase, to identify patients with advanced head and neck cancer, responding or not responding to initiated therapy. The tumour metabolic rate of glucose (MRgl) examined by 2-18FDG-PET was determined in 17 patients before and after the first weeks of either radiotherapy (16-35 Gy) or one course of combination chemotherapy. Metabolic values uptake values normalized to plasma activity integrals--were correlated to loco-regional outcome, as evaluated 5-6 weeks after completion of treatment. Initial low tumour MRgl (<20 micromol/min/100 g tissue), in primary lesions or regional metastases, predicted a local complete response. When a high initial tumour MRgl was found, the magnitude of the reduction of MRgl in the second PET examination might be an adjunct in predicting local tumour response.
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| 2. |
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| 3. |
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| 4. |
- Garkavij, Michael, et al.
(författare)
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Enhanced radioimmunotargeting of 125I-labeled L6-biotin monoclonal antibody (MAb) by combining preload of cold L6 MAb and subsequent immunoadsorption in rats
- 1995
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Ingår i: Cancer Research. - 1538-7445. ; 55:23 Suppl, s. 5874-5880
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates whether tumor:normal tissue uptake ratios of radiolabeled monoclonal antibodies can be further improved by a combination of extracorporeal immunoadsorption (ECIA) and preload with unlabeled idiotypic monoclonal antibody. Athymic rats, heterotransplanted with human lung carcinoma under the kidney capsule (SR tumor) and i.m. (IM tumor), were divided into four study groups: controls, ECIA, preload, and combined preload+ECIA. The preload+ECIA procedure reduced the whole-body and plasma activity by 48 and 89%, respectively. After such combined procedure, the uptake of 125I-labeled L6-biotin in SR tumors was unchanged, while the uptake in normal tissues was considerably reduced. Tumor (T):bone marrow ratio was then increased by 17.5 times (after ECIA) and by 4.5 times (24 h after ECIA). Similar enhancements were achieved for T:liver and T:kidney ratios. For the IM tumors, the ratios were not as high as for SR tumors. The effects on T:normal ratios of preload+ECIA in combination were synergistic. The combined procedure resulted both in an increased uptake and prolonged persistence of 125I-labeled L6-biotin in the SR tumors and also in a reduction of corresponding uptake values in organs critical for radiation.
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| 5. |
- Garkavij, Michael, et al.
(författare)
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Extracorporeal immunoadsorption from whole blood based on the avidin-biotin concept. Evaluation of a new method
- 1996
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 35:3, s. 309-312
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Tidskriftsartikel (refereegranskat)abstract
- This study of 36 rats with rat colon adenocarcinoma transplants was carried out to investigate the efficacy of a new method of whole blood immunoadsorption (WBIA) in removing biotinylated monoclonal antibodies (MAbs) directly from unseparated blood, in order to increase 'the tumor/normal-tissue uptake ratio', as compared with extracorporeal immunoadsorption (ECIA) of antibodies from plasma. Compared with the ECIA system, the overall volume of the WBIA system (comprising only a pump, an adsorption column, a drop-chamber and tubings) was less (3.6 vs. 6.2 ml), and procedure duration 2 h less. The 17 rats undergoing the WBIA procedure, started 12 h after i.v. injection of 4.0-4.5 MBq 125I-BR96-biotin, manifested neither hemolysis nor any other complication; no signs of organ edema were found at dissection; whole body and blood radioactivity values were reduced by 51% and 89.5%, respectively. The WBIA method was as effective as ECIA, but technically simpler, safer and more reliable.
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| 6. |
- Garkavij, Martin, et al.
(författare)
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Extracorporeal whole-blood immunoadsorption enhances radioimmunotargeting of iodine-125-labeled BR96-biotin monoclonal antibody
- 1997
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 38:6, s. 895-901
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the efficacy of tumor radioimmunotargeting with 125I-labeled BR96-biotin monoclonal antibody using a new method, whole-blood immunoadsorption (WBIA), based on direct adsorption of unbound monoclonal antibody (MAb) from blood without preceding separation of plasma. METHODS: Highly tumor-reactive, internalizing, chimeric BR96 MAb of isotype IgG1 binds to a tumor-associated Lewis-type (Le(Y)) cell surface antigen. Forty-six Brown Norwegian male rats were inoculated intramuscularly and beneath the liver or kidney capsule with syngeneic rat colon carcinoma BN7005, expressing Lewis-type antigen, and investigated. The rats were injected intravenously with 3.5-4.5 MBq 125I-labeled BR96-biotin. Twenty of the rats underwent WBIA starting 5 or 12 hr after injection. About six blood volumes were passed through an avidin-gel adsorption column during 2 hr. RESULTS: By using WBIA, whole-body radioactivity was reduced by 50%, and plasma activity by 85%. Both directly after completion of WBIA and 33 hr later, the activity uptake in tumors manifested only a nonsignificant decrease as compared with corresponding controls (p > 0.05) and had approximately similar time-activity curves. Uptake ratios for tumor (T):bone marrow, T:liver, T:kidney and T:lung were enhanced 2.3- to 3.5-fold in all three tumor models, as compared with controls. The ratio of liver tumor to bone marrow was improved from 10:1 to 30:1. CONCLUSION: This new method of WBIA yields significantly improved radioimmunotargeting of highly tumor-reactive, internalizing MAb BR96.
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| 7. |
- Jonsson, Ann-Charlotte, et al.
(författare)
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Cell survival after Auger electron emission from stable intracellular indium exposed to monochromatic synchrotron radiation
- 1996
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 35:7, s. 947-952
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Tidskriftsartikel (refereegranskat)abstract
- The biological effect of Auger electrons emitted from indium in V79 cells was investigated. K-shell vacancies were induced by synchrotron x-rays. Two energies, 100 eV above and below the K-edge of indium, were used. The cell survival for controls was similar to that which has been reported by others, with D37 = 4.4 Gy. Indium-oxine-labelled cells exhibited a survival clearly below that of the controls, D37 = 3.2 Gy, but no significant difference in survival between irradiations above and below the K-edge could be observed. The explanation is, inter alia, that the number of photons interacting with indium atoms incorporated into the cell, is small compared with the number of photons interacting with other atoms in the cell. The toxicity of indium oxine made it impossible to incorporate a sufficient number of indium atoms into the cells to observe a difference in this study. However, monoenergetic irradiation above and below the K-edge, provides a technique for the investigation of basic biological effects of Auger processes.
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| 8. |
- Lindén, Ola, et al.
(författare)
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Radioimmunotherapy using 131I-labeled anti-CD22 monoclonal antibody (LL2) in patients with previously treated B-cell lymphomas
- 1999
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 5:10 Suppl, s. 3287-3291
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Tidskriftsartikel (refereegranskat)abstract
- Experience in using rapidly internalizing antibodies, such as the anti-CD22 antibody, for radioimmunotherapy of B-cell lymphomas is still limited. The present study was conducted to assess the efficacy and toxicity of a 131I-labeled anti-CD22 monoclonal antibody (mAb), LL2, in patients with B-cell lymphomas failing first- or second-line chemotherapy. Eligible patients were required to have measurable disease, less than 25% B cells in unseparated bone marrow, and an uptake of 99mTc-labeled LL2Fab' in at least one lymphoma lesion on immunoscintigram. Eight of nine patients examined with immunoscintigraphy were unequivocally found to have an uptake, and therapy with 131I-labeled anti-CD22 [1330 MBq/m2 (36 mCi/m2)] preceded by 20 mg of naked anti-CD22 mAb was administered. Three patients achieved partial remission (duration, 12, 3, and 2 months), and one patient with progressive lymphoma showed stable disease for 17 months. Four patients exhibited progressive disease. The toxicity was hematological. Patients with subnormal counts of neutrophils or platelets before therapy seemed to be more at risk for hematological side effects. Radioimmunotherapy in patients with B-cell lymphomas using 131I-labeled mouse anti-CD22 can induce objective remission in patients with aggressive as well as indolent lymphomas who have failed prior chemotherapy.
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| 9. |
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| 10. |
- Mardirossian, G, et al.
(författare)
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A new rectal model for dosimetry applications
- 1999
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 40:9, s. 1524-1531
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Tidskriftsartikel (refereegranskat)abstract
- A revised geometric representative model of the lower part of the colon, including the rectum, the urinary bladder and prostate, is proposed for use in the calculation of absorbed dose from injected radiopharmaceuticals. The lower segment of the sigmoid colon as described in the 1987 Oak Ridge National Laboratory mathematical phantoms does not accurately represent the combined urinary bladder/rectal/prostate geometry. In the revised model in this study, the lower part of the abdomen includes an explicitly defined rectum. The shape of sigmoid colon is more anatomically structured, and the diameters of the descending colon are modified to better approximate their true anatomic dimensions. To avoid organ overlap and for more accurate representation of the urinary bladder and the prostate gland (in the male), these organs are shifted from their originally defined positions. The insertion of the rectum and the shifting of the urinary bladder will not overlap with or displace the female phantom's ovaries or the uterus. In the adult male phantom, the prostatic urethra and seminal duct are also included explicitly in the model. The relevant structures are defined for the newborn and 1-, 5-, 10- and 15-y-old (adult female) and adult male phantoms. METHODS: Values of the specific absorbed fractions and radionuclide S values were calculated with the SIMDOS dosimetry package. Results for 99mTc and other radionuclides are compared with previously reported values. RESULTS: The new model was used to calculate S values that may be crucial to calculations of the effective dose equivalent. For 131I, the S (prostate<--urinary bladder contents) and S (lower large intestine [LLI] wall<--urinary bladder contents) are 6.7 x 10(-6) and 3.41 x 10(-6) mGy/MBq x s, respectively. Corresponding values given by the MIRDOSE3 computer program are 6.23 x 10(-6) and 1.53 x 10(-6) mGy/MBq x s, respectively. The value of S (rectum wall<--urinary bladder contents) is 4.84 x 10(-5) mGy/MBq x s. For 99mTc, we report S (testes<--prostate) and S (LLI wall<--prostate) of 9.41 x 10(-7) and 1.53 x 10(-7) mGy/MBq x s versus 1.33 x 10(-6) and 7.57 x 10(-6) mGy/MBq x s given by MIRDOSE3, respectively. The value of S (rectum wall<--prostate) for 99mTc is given as 4.05 x 10(-6) mGy/MBq x s in the present model. CONCLUSION: The new revised rectal model describes an anatomically realistic lower abdomen region, thus giving improved estimates of absorbed dose. Due to shifting the prostate gland, a 30%-45% reduction in the testes dose and the insertion of the rectum leads to 48%-55% increase in the LLI wall dose when the prostate is the source organ.
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