Prolonged survival of Fischer rats bearing F98 glioma after iodine-enhanced synchrotron stereotactic radiotherapy.
OBJECTIVE
Heavy-atom-enhanced synchrotron stereotactic radiotherapy (SSR) is a treatment that involves selective accumulation of high-Z elements in tumors followed by stereotactic irradiation with X-rays from a synchrotron source. The purpose of this study was to determine whether the efficacy of iodine-enhanced SSR could be further improved in the F98 rodent glioma model, by using a concomitant injection of an iodinated contrast agent and a transient blood-brain barrier opener (mannitol) during irradiation.


METHODS
Fourteen days after intracerebral inoculations of F98 cells, the rats were irradiated with 50-keV X-rays while receiving an infusion of hyperosmotic mannitol with iodine, either intravenously or via the carotid (9 to 15 rats per group, 117 rats total).


RESULTS
For doses<or=15 Gy, the intracarotid infusion of mannitol and iodine improved the rats' survival compared with intravenous injection or irradiation alone. The percentage-increased life spans (ILS) were 91%, 116%, and 169% without iodine, after infusion of iodine and mannitol intravenously, and intracarotid, respectively (15 Gy). At 25 Gy, the rats irradiated without iodine had the longest survival (ILS=607%), but no additional benefit was obtained with iodine and mannitol.


CONCLUSIONS
Iodine-enhanced SSR is significantly improved with concomitant intracarotid infusion of iodine and mannitol for radiation doses<or=15 Gy.
Adam
Jean-François
JF
INSERM U647, Grenoble, France.
Joubert
Aurélie
A
Biston
Marie-Claude
MC
Charvet
Anne-Marie
AM
Peoc'h
Michel
M
Le Bas
Jean-François
JF
Balosso
Jacques
J
Estève
François
F
Elleaume
Hélène
H
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism / Q000401:mortality / Q000532:radiotherapy*; D003287:Contrast Media / Q000493:pharmacokinetics*; D005910:Glioma / Q000378:metabolism / Q000401:mortality / Q000532:radiotherapy*; D007479:Iopamidol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D008353:Mannitol / Q000494:pharmacology; D011879:Radiotherapy Dosage; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344; D013238:Stereotaxic Techniques / Q000295:instrumentation; D017356:Synchrotrons; D014057:Tomography, X-Ray Computed / Q000379:methods
D003287:Contrast Media; C057937:iomeprol; D008353:Mannitol; D007479:Iopamidol