Effectiveness of monoenergetic and spread-out bragg peak carbon-ions for inactivation of various normal and tumour human cell lines.
This work aimed at measuring cell-killing effectiveness of monoenergetic and Spread-Out Bragg Peak (SOBP) carbon-ion beams in normal and tumour cells with different radiation sensitivity. Clonogenic survival was assayed in normal and tumour human cell lines exhibiting different radiosensitivity to X- or gamma-rays following exposure to monoenergetic carbon-ion beams (incident LET 13-303 keV/microm) and at various positions along the ionization curve of a therapeutic carbon-ion beam, corresponding to three dose-averaged LET (LET(d)) values (40, 50 and 75 keV/microm). Chinese hamster V79 cells were also used. Carbon-ion effectiveness for cell inactivation generally increased with LET for monoenergetic beams, with the largest gain in cell-killing obtained in the cells most radioresistant to X- or gamma-rays. Such an increased effectiveness in cells less responsive to low LET radiation was found also for SOBP irradiation, but the latter was less effective compared with monoenergetic ion beams of the same LET. Our data show the superior effectiveness for cell-killing exhibited by carbon-ion beams compared to lower LET radiation, particularly in tumour cells radioresistant to X- or gamma-rays, hence the advantage of using such beams in radiotherapy. The observed lower effectiveness of SOBP irradiation compared to monoenergetic carbon beam irradiation argues against the radiobiological equivalence between dose-averaged LET in a point in the SOBP and the corresponding monoenergetic beams.
Belli
Mauro
M
Istituto Superiore di Sanità and INFN-Sezione di Roma1-Gruppo Collegato di Sanità, Roma, Italy.
Bettega
Daniela
D
Calzolari
Paola
P
Cherubini
Roberto
R
Cuttone
Giacomo
G
Durante
Marco
M
Esposito
Giuseppe
G
Furusawa
Yoshiya
Y
Gerardi
Silvia
S
Gialanella
Giancarlo
G
Grossi
Gianfranco
G
Manti
Lorenzo
L
Marchesini
Renato
R
Pugliese
Mariagabriella
M
Scampoli
Paola
P
Simone
Giustina
G
Sorrentino
Eugenio
E
Tabocchini
Maria Antonella
MA
Tallone
Lucia
L
D017209:Apoptosis / Q000528:radiation effects*; D002247:Carbon Isotopes; D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D020450:Heavy Ions; D006801:Humans; D009369:Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D011829:Radiation Dosage; D012542:Scattering, Radiation
D002247:Carbon Isotopes