Effect of fractionated versus unfractionated total body irradiation on the growth of the BN acute myelocytic leukemia

Journal Article · Sat Aug 01 04:00:00 EDT 1981 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(81)90162-0· OSTI ID:5821764

Hagenbeek, A; Martens, A C.M.

The efficacy of various total body irradiation (TBI) regimens prior to bone marrow transplantation was evaluated in a rat model for acute myelocytic leukemia (Dq = 85.1 cGy gamma ; N = 3.7). Using high dose rate gamma-irradiation (115 cGy/min), fractionated TBI with large total daily doses (400 to 600 cGy), either given as acute doses or as split doses at 8 hr intervals, was most effective. Split doses (2 fractions per day) offered no additional advantage. At the most, a 4 log leukemic cell kill was induced. No lethal toxicity was observed. Nine-hundred cGy flash TBI had a similar anti-tumor effect, but with this regimen almost half of the rats died from radiation-induced toxicity (lungs and gastro-intestinal tract). The results are explained in terms of differences between normal and leukemic cells as regards (a) repair of sublethal damage; and (b) repopulation. Low dose rate continuous gamma-irradiation (0.26 cGy/min) with total doses ranging from 900 to 2000 cGy was also quite effective. Maximally a 4 log cell kill was obtained. With 2000 cGy, 50% of the rats died from the gastro-intestinal tract-syndrome. In addition to the major role played by chemotherapy, TBI is mainly of importance in sterilizing the various sanctuaries in the body which contain leukemic cells anatomically resistant to most cytostatic agents.

• Research Organization: Dutch Organization for Applied Scientific Research, Rijswijk, Netherlands
• OSTI ID: 5821764
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 7:8; ISSN IOBPD
• Country of Publication: United States
• Language: English

Related Subjects

550603* -- Medicine-- External Radiation in Therapy-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMAL TISSUES
ANIMALS
BODY
BONE MARROW
COMPARATIVE EVALUATIONS
CUMULATIVE RADIATION EFFECTS
DISEASES
DOSE-RESPONSE RELATIONSHIPS
DOSES
EXTERNAL IRRADIATION
FRACTIONATED IRRADIATION
HEMATOPOIETIC SYSTEM
HEMIC DISEASES
IRRADIATION
LEUKEMIA
MAMMALS
MEDICINE
NEOPLASMS
NUCLEAR MEDICINE
ORGANS
RADIATION DOSES
RADIOLOGY
RADIOTHERAPY
RATS
RODENTS
THERAPY
TISSUES
VERTEBRATES
WHOLE-BODY IRRADIATION