| 1. |
- Strand, Sven-Erik, et al.
(författare)
-
Radio-immunotherapy dosimetry with special emphasis on SPECT quantification and extracorporeal immuno-adsorption
- 1994
-
Ingår i: Medical & Biological Engineering & Computing. - 0140-0118. ; 32:5, s. 551-561
-
Forskningsöversikt (refereegranskat)abstract
- Results from therapeutic trials with radiolabelled monoclonal antibodies are difficult to compare, because of lack of accurate macroscopic and microscopic dosimetry for both tumours and normal tissues. Requirements for such a dosimetry are covered in the paper. Accurate in vivo dosimetric measurement techniques for verification of calculated absorbed doses are also needed to verify treatment planning. In the review, important topics related to dosimetry in therapeutic trials in RIT are covered, such as, absorbed-dose calculations and activity-quantification techniques for planar imaging and SPECT. The latter is particularly discussed, including a summary of different correction techniques. Absorbed-dose calculations and treatment-planning techniques are also discussed. Possible ways of enhancing the therapeutic ratio are reviewed, especially the novel technique with extracorporeal immuno-adsorption. The review could form the basis of the development of future treatment-planning protocols and for dosimetry calculations in radio-immunotherapy, considering some of the most important parameters for approaching an accurate in vivo dosimetry.
|
|
| 2. |
- Garkavij, Michael, et al.
(författare)
-
Improving radioimmonotargeting of tumors. Variation in the amount of L6 MAb administered, combined with an immunoadsorption system (ECIA)
- 1993
-
Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 32:7-8, s. 853-859
-
Tidskriftsartikel (refereegranskat)abstract
- Extracorporeal immunoadsorption (ECIA) is a new method for the selective removal of circulating radiolabeled monoclonal antibodies (MAb) from plasma to increase the uptake in tumor versus normal tissues (T/N-ratio). To ascertain whether the amount of MAb affects T/N ratios immediately and 24 h after ECIA, we used a rat model with two tumor sites--one intramuscular (im) and one below the subrenal capsule (SR). Extracorporeal immunoadsorption was done with an avidin-agarose column after injection of 125I-labeled biotinylated L6 MAb. The animals received 10, 50 or 250 micrograms of L6 only (controls), or followed by ECIA. The efficacy of the procedure in removing plasma activity was 80-95%. For both tumor sites, the highest T/N-ratios were obtained with 10 micrograms L6. All T/N-ratios significantly improved for SR tumors by a factor ranging from 3.2 (lung) to 12.6 (bone marrow). The T/N-ratios were still elevated 24 h after ECIA. Injection of larger amounts of MAb, probably causing a higher degree of tumor saturation, will not necessarily improve the T/N ratio after ECIA.
|
|
| 3. |
- Garkavij, Michael, et al.
(författare)
-
Improving radioimmunotargeting of tumors: the impact of preloading unlabeled L6 monoclonal antibody on the biodistribution of 125I-L6 in rats
- 1994
-
Ingår i: Journal of nuclear biology and medicine (Turin, Italy : 1991). - 0368-3249. ; 38:4, s. 594-600
-
Tidskriftsartikel (refereegranskat)abstract
- In the radioimmunotherapy of malignancies the uptake of monoclonal antibodies (MoAb) is commonly low in tumors compared with normal tissue. Several methods have been suggested to increase the tumor-to-normal tissue (T/N) ratio. In this study we have investigated the biodistribution of different amounts of 125I-L6-biotin MoAb in combination with a preload of unlabeled L6 MoAb. Nude rats were injected with 50 micrograms or 250 micrograms of unlabeled L6 24 hours prior to the injection of 10 micrograms, 50 micrograms or 250 micrograms of 125I-L6, antipancarcinoma MoAb. Dissections were performed 24 hours after the injection of radiolabeled MoAb. The maximal enhancement of tumor uptake with simultaneously decreased uptake in normal tissues was with 250 micrograms of 125I-L6 preceded by a preload of 50 micrograms unlabeled L6. Mean T/N ratios were improved by a factor of 2.9 for bone marrow, 3.4 for liver, 3.7 for lungs and 2.3 for kidneys as compared with the corresponding controls. This study demonstrated that preinjection of optimal amounts of unlabeled L6 MoAb may increase the uptake of 125I-L6 by tumor and improve the T/N ratios. Based on present data, preloading with unlabeled MoAb should be considered in future clinical studies with immunoconjugates to improve the radioimmunotargeting of tumors. It is essential to titrate an appropriate amount of the preload, thus avoiding possible tumor antigen saturation of unlabeled MoAbs but simultaneously decreasing the uptake of subsequently injected radiolabeled MoAb in normal tissues.
|
|
| 4. |
|
|
| 5. |
- Strand, Sven-Erik, et al.
(författare)
-
A general extracorporeal immunoadsorption method to increase tumor-to-tissue ratio
- 1994
-
Ingår i: Cancer. - 1097-0142. ; 73:3 Suppl, s. 1033-1037
-
Tidskriftsartikel (refereegranskat)abstract
- The idea of applying extracorporeal immunoadsorption (ECIA) in radioimmunodiagnosis and radioimmunotherapy has been proposed previously. The authors here report on the development of new concept using a general method for ECIA based on biotinylated MoAb adsorbed on an avidin column. Athymic rats heterotransplanted with either human melanomas or human lung carcinoma were injected with iodine-125-labeled biotinylated 96.5 or L6 MoAb, respectively. At 24 or 48 hours after the injection, ECIA was performed by pumping blood through a hollow-fiber plasma filter. The separated plasma then was passed through an absorbent (avidin-agarose) column. The whole ECIA procedure lasted for 3 hours. By this ECIA method, the tumor-to-normal tissue ratios were increased in various tissues (i.e., radiosensitive and blood rich organs) by a factor of four to five.
|
|
