Radiofrequency electromagnetic fields have no effect on the in vivo proliferation of the 9L brain tumor.
The intracranial 9L tumor model was used to determine if exposure to a radiofrequency (RF) electromagnetic field similar to those used in cellular telephone has any effects on the growth of a central nervous system tumor. Fischer 344 rats implanted with different numbers of 9L gliosarcoma cells were exposed to 835.62 MHz frequency-modulated continuous wave (FMCW) or 847.74 MHz code division multiple access (CDMA) RF field with nominal slot-average specific absorption rates in the brain of 0.75 +/- 0.25 W/kg. The animals were exposed to the RF field for 4 h a day, 5 days a week starting 4 weeks prior to and up to 150 days after the implantation of tumor cells. Among sham-exposed animals injected with 2 to 10 viable cells (group 1), the median survival was 70 days, with 27% of the animals surviving at 150 days. The median survival length and final survival fraction for animals injected with 11 to 36 viable cells (group 2) were 52 days and 14%, respectively, while the values for those injected with 37 to 100 cells (group 3) were 45 days and 0%. The animals exposed to CDMA or FMCW had similar survival parameters, and the statistical comparison of the survival curves for each of the groups 1, 2 and 3 showed no significant differences compared to sham-exposed controls.
Higashikubo
R
R
Radiation Oncology Center, Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63108, USA.
Culbreth
V O
VO
Spitz
D R
DR
LaRegina
M C
MC
Pickard
W F
WF
Straube
W L
WL
Moros
E G
EG
Roti
J L
JL
D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology*; D002455:Cell Division / Q000528:radiation effects*; D004574:Electromagnetic Fields; D018316:Gliosarcoma / Q000473:pathology*; D008297:Male; D011846:Radio Waves; D051381:Rats; D011916:Rats, Inbred F344; D015996:Survival Rate; D013689:Telephone; D014407:Tumor Cells, Cultured