Influence of cellular radiation sensitivity on local tumor control of human melanoma xenografts given fractionated radiation treatment

Journal Article · Sun Sep 01 04:00:00 EDT 1991 · Cancer Research; (United States)

OSTI ID:5227684

Rofstad, E K ^[1]

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1. Institute for Cancer Research, Norwegian Radium Hospital, Montebello, Oslo (Norway)

The radiocurability of human melanoma xenografts was studied by treating tumors with multiple fractions of 2.0 Gy and using local tumor control at 180 days as end point. Three melanoma lines (E. F., G. E., M. F.) that are only weakly immunogenic in athymic nude mice (BALB/c-nu/nu/BOM) were selected for the study. The tumor radiocurability was found to differ considerably among the lines; the radiation doses required to achieve local control of 50% of the tumors irradiated (TCD50s; mean {plus minus} SE) were 85.0 {plus minus} 4.7 Gy (E.F.), 60.3 {plus minus} 5.4 Gy (G.E.), and 99.3 {plus minus} 5.7 Gy (M. F.). The radiation sensitivity in vitro of cells isolated directly from tumors also differed significantly among the lines. The TCD50 showed positive correlations with the surviving fraction after 2.0 Gy in vitro, the surviving fraction after two doses of 2.0 Gy (4-h interval) in vitro, and the surviving fraction after 4.0 Gy at a low dose rate (1.25 cGy/min) in vitro. Thus, the differences in tumor radiocurability among the lines were mainly a consequence of cellular differences in the capacity to repair radiation damage. Comparisons of measured TCD50s with theoretical TCD50s, calculated from cell-surviving fractions measured in vitro after radiation treatment in vitro or in vivo, suggested that other tumor parameters, e.g., rate of population between radiation fractions, also had a significant impact on the TCD50. However, this study strongly supports the assumptions that the surviving fraction at 2.0 Gy in vitro is a useful parameter for prediction of clinical tumor radiocurability.

• OSTI ID: 5227684
• Journal Information: Cancer Research; (United States), Journal Name: Cancer Research; (United States) Vol. 51:17; ISSN 0008-5472; ISSN CNREA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
DISEASES
DOSES
EXPERIMENTAL NEOPLASMS
FRACTIONATED IRRADIATION
IRRADIATION
MAMMALS
MELANOMAS
MICE
NEOPLASMS
RADIATION DOSES
RADIOSENSITIVITY
RODENTS
TUMOR CELLS
VERTEBRATES