Response of a rat rhabdomyosarcoma to neon- and helium-ion irradiation

Journal Article · Mon May 01 04:00:00 EDT 1978 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574888· OSTI ID:6817164

Curtis, S B; Tenforde, T S; Parks, D; Schilling, W A; Lyman, J T

The response of a rhabdomyosarcoma tumor in an inbred strain of rat has been measured after irradiation by charged-particle beams of helium and neon ions. Tumor volume regression and regrowth and tumor cure were measured and compared with results from 220-kVp x irradiation. RBEs for 20-day radiation-induced growth delay (RBE/sub 20/), for 50-day radiation-induced growth delay (RBE/sub 50/), and for 50% tumor cure probability (RBE/sub TCD50/180/) were measured in the plateau (high energy and spread-out Bragg-peak (low energy) ionization regions of both charged-particle beams. In the neon-ion peak region, RBE/sub 20/, RBE/sub 50/, and RBE/sub TCD50/180/ values (with standard deviations) of 2.9 -+ 0.7, 2.6 -+ 0.5, and 3.1 -+ 0.6, respectively, were obtained. These high values reflect the effect of a high-LET contribution in the beam and possibly the presence of a significant hypoxic fraction in this tumor. In the neon plateau region, RBE/sub 20/ and RBE/sub 50/ values of 1.7 -+ 0.4 and 1.8 -+ 0.3 were obtained. These values are significantly lower than those in the peak region and indicate a marked difference in beam quality between the peak and plateau regions of the beam. This characteristic may make the neon beam a candidate for possible use in the radiotherapy of human tumors. For the helium-ion Bragg-peak position, RBE/sub 20/, RBE/sub 50/, and RBE/sub TCD50/180/ values of 1.5 -+ 0.3, 1.4 -+ 0.3, and 1.4 -+ 0.2, respectively, were obtained. These values indicate that there is a significant increase in biological effectiveness in the helium-ion spread-out peak region. For the helium-ion plateau region, RBE/sub 20/ and RBE/sub 50/ values of 1.0 -+ 0.2 and 1.1 -+ 0.2 indicate that this region can be considered a region of low-LET radiation.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6817164
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 74:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CHARGED PARTICLES
DISEASES
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY TRANSFER
HELIUM IONS
IONIZING RADIATIONS
IONS
IRRADIATION
LET
LOCAL IRRADIATION
MAMMALS
MYOSARCOMAS
NEON IONS
NEOPLASMS
RADIATION EFFECTS
RADIATIONS
RATS
RBE
RHABDOMYOSARCOMAS
RODENTS
SARCOMAS
VERTEBRATES
X RADIATION